Bitmap
(Redirected from Basic bitmap storage)
You are encouraged to solve this task according to the task description, using any language you may know.
Show a basic storage type to handle a simple RGB raster graphics image, and some primitive associated functions.
If possible provide a function to allocate an uninitialised image, given its width and height, and provide 3 additional functions:
- one to fill an image with a plain RGB color,
- one to set a given pixel with a color,
- one to get the color of a pixel.
(If there are specificities about the storage or the allocation, explain those.)
These functions are used as a base for the articles in the category raster graphics operations,
and a basic output function to check the results
is available in the article write ppm file.
11l
T Colour = BVec3
V black = Colour(0, 0, 0)
V white = Colour(255, 255, 255)
T Bitmap
Int width, height
Colour background
[[Colour]] map
F (width = 40, height = 40, background = white)
assert(width > 0 & height > 0)
.width = width
.height = height
.background = background
.map = [[background] * width] * height
F fillrect(x, y, width, height, colour = black)
assert(x >= 0 & y >= 0 & width > 0 & height > 0)
L(h) 0 .< height
L(w) 0 .< width
.map[y + h][x + w] = colour
F chardisplay()
V txt = .map.map(row -> row.map(bit -> (I bit == @@.background {‘ ’} E ‘@’)).join(‘’))
txt = txt.map(row -> ‘|’row‘|’)
txt.insert(0, ‘+’(‘-’ * .width)‘+’)
txt.append(‘+’(‘-’ * .width)‘+’)
print(reversed(txt).join("\n"))
F set(x, y, colour = black)
.map[y][x] = colour
F get(x, y)
R .map[y][x]
V bitmap = Bitmap(20, 10)
bitmap.fillrect(4, 5, 6, 3)
assert(bitmap.get(5, 5) == black)
assert(bitmap.get(0, 1) == white)
bitmap.set(0, 1, black)
assert(bitmap.get(0, 1) == black)
bitmap.chardisplay()- Output:
+--------------------+ | | | | | @@@@@@ | | @@@@@@ | | @@@@@@ | | | | | | | |@ | | | +--------------------+
Action!
Part of the solution can be found in RGBIMAGE.ACT
INCLUDE "H6:RGBIMAGE.ACT" ;from task Bitmap
RGB black,yellow,violet,blue
PROC DrawImage(RgbImage POINTER img BYTE x,y)
RGB c
BYTE i,j
FOR j=0 TO img.h-1
DO
FOR i=0 TO img.w-1
DO
GetRgbPixel(img,i,j,c)
IF RgbEqual(c,yellow) THEN
Color=1
ELSEIF RgbEqual(c,violet) THEN
Color=2
ELSEIF RgbEqual(c,blue) THEN
Color=3
ELSE
Color=0
FI
Plot(x+i,y+j)
OD
OD
RETURN
PROC Main()
RgbImage img
BYTE CH=$02FC,width=[80],height=[60]
BYTE ARRAY ptr(14400)
BYTE i,x,y,c
Graphics(7+16)
SetColor(0,13,12) ;yellow
SetColor(1,4,10) ;violet
SetColor(2,8,6) ;blue
SetColor(4,0,0) ;black
RgbBlack(black)
RgbYellow(yellow)
RgbViolet(violet)
RgbBlue(blue)
InitRgbImage(img,width,height,ptr)
FillRgbImage(img,blue)
FOR i=1 TO 1000
DO
c=Rand(3)
x=Rand(width)
y=Rand(height)
IF c=0 THEN
SetRgbPixel(img,x,y,yellow)
ELSEIF c=1 THEN
SetRgbPixel(img,x,y,violet)
ELSE
SetRgbPixel(img,x,y,black)
FI
OD
DrawImage(img,(160-width)/2,(96-height)/2)
DO UNTIL CH#$FF OD
CH=$FF
RETURN- Output:
Screenshot from Atari 8-bit computer
ActionScript
ActionScript 3 has a BitmapData class (in the flash.display package) which can be used for storage and handling of bitmap images.
To display these images, the Bitmap class can be used.
// To import the BitmapData class:
import flash.display.BitmapData;
// Creates a new BitmapData object with a width of 500 pixels and a height of 300 pixels.
var bitmap:BitmapData = new BitmapData(500, 300);
// Create a BitmapData with transparency disallowed
var opaqueBitmap:BitmapData = new BitmapData(500, 300, false);
// Bitmap with initial fill colour, as 0xAARRGGBB (default is white)
var redFilledBitmap:BitmapData = new BitmapData(400, 300, true, 0xFFFF0000);
// Get the colour value of the pixel at point (200, 200)
bitmap.getPixel(200, 200) // As 0xRRGGBB
bitmap.getPixel32(200, 200) // As 0xAARRGGBB
// Set the colour value of the pixel at point (300, 200) to blue
bitmap.setPixel(300, 200, 0x0000FF); // As 0xRRGGBB
bitmap.setPixel32(300, 200, 0xFF0000FF); // As 0xAARRGGBB
// Fill the bitmap with a given colour (as 0xAARRGGBB) after construction
bitmap.fillRect(bitmap.rect, 0xFF44FF44);
Ada
The package interface:
package Bitmap_Store is
type Luminance is mod 2**8;
type Pixel is record
R, G, B : Luminance := Luminance'First;
end record;
Black : constant Pixel := (others => Luminance'First);
White : constant Pixel := (others => Luminance'Last);
type Image is array (Positive range <>, Positive range <>) of Pixel;
procedure Fill (Picture : in out Image; Color : Pixel);
procedure Print (Picture : Image);
type Point is record
X, Y : Positive;
end record;
end Bitmap_Store;
The implementation of:
with Ada.Text_IO; use Ada.Text_IO;
package body Bitmap_Store is
procedure Fill (Picture : in out Image; Color : Pixel) is
begin
for p of Picture loop x:= Color;end loop;
end Fill;
procedure Print (Picture : Image) is
begin
for I in Picture'Range (1) loop
for J in Picture'Range (2) loop
Put (if Picture (I, J) = White then ' ' else 'H');
end loop;
New_Line;
end loop;
end Print;
end Bitmap_Store;
This can be used like:
use Bitmap_Store; with Bitmap_Store;
...
X : Image (1..64, 1..64);
begin
Fill (X, (255, 255, 255));
X (1, 2) := (R => 255, others => 0);
X (3, 4) := X (1, 2);
ALGOL 68
Note: short and shorten need to be tuned (added or removed) to match the underlying graphic hardware colour depth.
File: prelude/Bitmap.a68
# -*- coding: utf-8 -*- #
MODE PIXEL = STRUCT(#SHORT# BITS red,green,blue);
MODE POINT = STRUCT(INT x,y);
MODE IMAGE = [0,0]PIXEL; # instance attributes #
MODE CLASSIMAGE = STRUCT ( # class attributes #
PIXEL black, red, green, blue, white,
PROC (REF IMAGE)REF IMAGE init,
PROC (REF IMAGE, PIXEL)VOID fill,
PROC (REF IMAGE)VOID print,
# virtual: #
REF PROC (REF IMAGE, POINT, POINT, PIXEL)VOID line,
REF PROC (REF IMAGE, POINT, INT, PIXEL)VOID circle,
REF PROC (REF IMAGE, POINT, POINT, POINT, POINT, PIXEL, UNION(INT, VOID))VOID cubic bezier
);
CLASSIMAGE class image = (
# black = # (#SHORTEN# 16r00, #SHORTEN# 16r00, #SHORTEN# 16r00),
# red = # (#SHORTEN# 16rff, #SHORTEN# 16r00, #SHORTEN# 16r00),
# green = # (#SHORTEN# 16r00, #SHORTEN# 16rff, #SHORTEN# 16r00),
# blue = # (#SHORTEN# 16r00, #SHORTEN# 16r00, #SHORTEN# 16rff),
# white = # (#SHORTEN# 16rff, #SHORTEN# 16rff, #SHORTEN# 16rff),
# PROC init = # (REF IMAGE self)REF IMAGE:
BEGIN
(fill OF class image)(self, black OF class image);
self
END,
# PROC fill = # (REF IMAGE self, PIXEL color)VOID:
FOR x FROM 1 LWB self TO 1 UPB self DO
FOR y FROM 2 LWB self TO 2 UPB self DO
self[x,y] := color
OD
OD,
# PROC print = # (REF IMAGE self)VOID:
printf(($n(UPB self)(3(16r2d))l$, self)),
# virtual: #
# REF PROC line = # LOC PROC (REF IMAGE, POINT, POINT, PIXEL)VOID,
# REF PROC circle = # LOC PROC (REF IMAGE, POINT, INT, PIXEL)VOID,
# REF PROC cubic bezier = # LOC PROC (REF IMAGE, POINT, POINT, POINT, POINT, PIXEL, UNION(INT, VOID))VOID
);
OP CLASSOF = (IMAGE image)CLASSIMAGE: class image;
OP INIT = (REF IMAGE image)REF IMAGE: (init OF (CLASSOF image))(image);
SKIPFile: test/Bitmap.a68
#!/usr/bin/a68g --script #
# -*- coding: utf-8 -*- #
### The test program ###
PR READ "prelude/Bitmap.a68" PR;
test:(
REF IMAGE x := INIT LOC[1:16, 1:16]PIXEL;
(fill OF class image) (x, white OF class image);
(print OF class image) (x)
)- Output:
(A 16x16 white block)
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
Applesoft BASIC
The Bitmap Address (BA) of the image is 24576 in order to maximize available space for the image without clobbering hi-res graphics memory. Just enough room is allocated for a P6 header. The Bitmap Beginning (BB) is just after the header.
HIMEM is set to 8192 which is just below hi-res graphics memory. It isn't necessary to protect hi-res graphics memory, but it doesn't hurt. Larger images can be allocated by using a lower Bitmap Address.
100 W = 8
110 H = 8
120 BB = 24576 + LEN ( STR$ (W) + STR$ (H)) + 9: REM P6 HEADER
130 HIMEM: 8192
140 R = 255
150 G = 255
160 B = 0
170 C = R + G * 256 + B * 65536
180 GOSUB 600FILL
190 X = 4
200 Y = 5
210 R = 127
220 G = 127
230 B = 255
240 C = R + G * 256 + B * 65536
250 GOSUB 500"SET PIXEL"
260 X = 3
270 Y = 2
280 GOSUB 400"GET PIXEL"
290 PRINT "COLOR="C" RED="R" GREEN="G" BLUE="B;
300 END
400 A = BB + X * 3 + Y * W * 3
410 R = PEEK (A)
420 G = PEEK (A + 1)
430 B = PEEK (A + 2)
440 C = R + G * 256 + B * 65536
450 RETURN
500 R = C - INT (C / 256) * 256
510 B = INT (C / 65536)
520 G = INT (C / 256) - B * 256
530 A = BB + X * 3 + Y * W * 3
540 POKE A,R
550 POKE A + 1,G
560 POKE A + 2,B
570 RETURN
600 FOR Y = 0 TO H - 1
610 FOR X = 0 TO W - 1
620 GOSUB 500"SET PIXEL"
630 NEXT X,Y
640 RETURN
ARM Assembly
The Game Boy Advance's video memory is located at address 0x06000000, and is 240 pixels by 160 pixels, with 16 bits defining the color of each pixel. This is a linear array of memory; storing 0xFFFF at 0x06000000 for example will immediately make the top-left pixel of the screen turn white. The following routines are intended for the bitmap screen modes, and have only been tested in screen mode 3. There is no need to allocate this video memory as it is always available thanks to the hardware.
Bitmap_FloodFill:
;input:
;r0 = color to fill screen with (15-bit color)
STMFD sp!,{r0-r12,lr}
MOV R2,#160
MOV R4,#0x06000000
outerloop_floodfill:
MOV R1,#240 ;restore inner loop counter
innerloop_floodfill:
strH r0,[r4]
add r4,r4,#2 ;next pixel
subs r1,r1,#1 ;decrement loop counter
bne innerloop_floodfill
subs r2,r2,#1
bne outerloop_floodfill
LDMFD sp!,{r0-r12,pc}
Bitmap_Locate:
;given x and y coordinates, offsets vram addr to that pixel on screen.
;input:
;r0 = x
;r1 = y
;output: r2 = vram area
STMFD sp!,{r4-r12,lr}
mov r2,#0x06000000 ;vram base
mov r4,#240*2 ;240 pixels across, 2 bytes per pixel
mul r1,r4,r1
add r2,r2,r1 ;add y*480
add r2,r2,r0,lsl #1 ;add x*2
LDMFD sp!,{r4-r12,pc}
Bitmap_StorePixel:
;input: r3 = color
;r0 = x
;r1 = y
bl Bitmap_Locate
strH r3,[r2] ;store the pixel color in video memory
bx lr
Bitmap_GetPixel:
;retrieves the color of the pixel at [r2] and stores its color value in r3.
;r0 = x
;r1 = y
;output in r3
bl Bitmap_Locate
ldrH r3,[r2]
bx lrATS
Because this code will be used in other tasks, I have separated it into "static" and "dynamic" source files. The former is the equivalent of an "interface" file in some other languages, and the latter is equivalent of an "implementation" file. I included some test code that gets compiled if you put the correct option on the compiler command line.
The ATS static file
This file should be called bitmap_task.sats.
#define ATS_PACKNAME "Rosetta_Code.bitmap_task"
(*------------------------------------------------------------------*)
(* I am going to do this at the most primitive level. So here is the
"abstractified" type, or really a whole set of different types:
w-by-h pixmap of values of type a, with pixel storage at address
p. The type is linear (‘use it once and only once’). We will make
pixmap a boxed type, so its size will be equal to that of a
pointer. (This is actually a general 2-dimensional array type!
But let us ignore that.) *)
absvtype pixmap (a : t@ype, w : int, h : int, p : addr) = ptr
(* A shorthand for a pixmap with its pixel storage at "some"
address. *)
vtypedef pixmap (a : t@ype, w : int, h : int) =
[p : addr] pixmap (a, w, h, p)
(* A shorthand for a pixmap with "some" width and height, and with its
pixel storage at "some" address. *)
vtypedef pixmap (a : t@ype) = [w, h : int] pixmap (a, w, h)
(* A shorthand for a pixmap with "some" POSITIVE width and POSITIVE
height, and with its pixel storage at "some" address. *)
vtypedef pixmap1 (a : t@ype) = [w, h : pos] pixmap (a, w, h)
(*------------------------------------------------------------------*)
(* Here are definitions for a small set of operations, including the
ones requested in the task document.
But note that, in ATS, we are careful about uninitialized data. It
is POSSIBLE to create an uninitialized pixmap, but NOT possible to
set or get individual pixels, if the pixmap is not already fully
initialized by some other means (such as "fill" or "load"). *)
fn {}
pixmap_width :
{a : t@ype}
{w, h : int}
(!pixmap (a, w, h)) -<> size_t w
fn {}
pixmap_height :
{a : t@ype}
{w, h : int}
(!pixmap (a, w, h)) -<> size_t h
fn {a : t@ype}
pixmap_make_array :
(* Make a new pixmap from an existing array. The array may be
anywhere (for instance, a stack frame or the heap), and need not
be initialized. *)
{w, h : int} {p : addr}
(array_v (a, p, w * h) | size_t w, size_t h, ptr p) ->
pixmap (a, w, h, p)
fn {a : t@ype}
pixmap_unmake :
(* Essentially the reverse of pixmap_make_array. Temporarily treat a
pixmap as an array. The array will be organized as rows from left
to right, with the rows themselves going from top to bottom. Thus
an index would be i = x + (y * w). *)
{w, h : int} {p : addr}
pixmap (a, w, h, p) ->
@(array_v (a, p, w * h) | size_t w, size_t h, ptr p)
prfn
pixmap_prove_index_bounds :
(* A proof that i = x + (y * w) is within bounds of the array
returned by pixmap_unmake. *)
{w, h : int}
{x, y : nat | x < w; y < h}
() -<prf>
[0 <= x + (y * w);
x + (y * w) < w * h]
void
fn {a : t@ype}
pixmap_make_uninitized :
(* Make a new uninitialized pixmap, with the pixels stored in the
heap. *)
{w, h : int}
(size_t w, size_t h) ->
[p : addr | null < p] @(mfree_gc_v p | pixmap (a?, w, h, p))
fn {a : t@ype}
pixmap_make_elt :
(* Make a new pixmap, initialized with a given element, with the
pixels stored in the heap. *)
{w, h : int}
(size_t w, size_t h, a) ->
[p : addr | null < p] @(mfree_gc_v p | pixmap (a, w, h, p))
fn {}
pixmap_free_storage_return :
(* Free a pixmap, returning the storage array to the user. *)
{a : t@ype}
{w, h : int} {p : addr}
pixmap (a, w, h, p) -> @(array_v (a, p, w * h) | ptr p)
fn {}
pixmap_free_storage_free :
(* If a pixmap's pixels were allocated in the heap, then free its
storage. *)
{a : t@ype}
{w, h : int} {p : addr}
(mfree_gc_v p | pixmap (a, w, h, p)) -> void
fn {a : t@ype}
pixmap_fill_elt :
(* Fill a pixmap with the given element. (Technically speaking, the
value of the first argument is consumed, and replaced by a new
value. Its type before and after is linear.) *)
{w, h : int} {p : addr}
(* The question mark means that the pixmap elements can start out
uninitialized. *)
(!pixmap (a?, w, h, p) >> pixmap (a, w, h, p), a) -> void
fn {a : t@ype}
{tk : tkind}
pixmap_set_at_guint :
(* Set a pixel at unsigned integer coordinates. You can do this only
on a pixmap that has been initialized. (It would be prohibitively
tedious to safely work with randomly located pixels, if the array
were not already fully initialized.) *)
{w, h : int}
{x, y : int | x < w; y < h}
(!pixmap (a, w, h), g1uint (tk, x), g1uint (tk, y), a) -> void
fn {a : t@ype}
{tk : tkind}
pixmap_set_at_gint :
(* Set a pixel, but with signed integer coordinates. *)
{w, h : int}
{x, y : nat | x < w; y < h}
(!pixmap (a, w, h), g1int (tk, x), g1int (tk, y), a) -> void
fn {a : t@ype} {tk : tkind}
pixmap_get_at_guint :
(* Get a pixel at unsigned integer coordinates. You can do this only
on a pixmap that has been initialized. *)
{w, h : int}
{x, y : int | x < w; y < h}
(!pixmap (a, w, h), g1uint (tk, x), g1uint (tk, y)) -> a
fn {a : t@ype} {tk : tkind}
pixmap_get_at_gint :
(* Get a pixel, but with signed integer coordinates. *)
{w, h : int}
{x, y : nat | x < w; y < h}
(!pixmap (a, w, h), g1int (tk, x), g1int (tk, y)) -> a
fn {a : t@ype}
pixmap_dump :
(* Dump the contents of a pixmap to an output stream, row by row as
in a PPM. You must implement the pixmap$pixels_dump template
function. (We are anticipating the task to write a PPM file, and
wish to do it in a nice way. I am likely to end up actually using
this code, after all.) *)
{w, h : int}
(* I return a success-or-failure value, to avoid committing to using
an exception here. There are circumstances in which exceptions are
not the best approach. *)
(FILEref, !pixmap (a, w, h)) -> bool (* success *)
fn {a : t@ype}
pixmap$pixels_dump :
(* A function that the writes n pixels to an output stream. (It
could be one pixel, it could be the entire image. From the user's
standpoint, it makes no difference. It is an implementation
detail HOW the function is called by pixmap_dump.) *)
{n : int}
(FILEref, &array (a, n), size_t n) -> bool (* success *)
fn {a : t@ype}
pixmap_load :
(* Load the contents of a pixmap from an input stream, row by row as
in a PPM. You must implement the pixmap$pixels_load template
function. A value of type a has to be given, to initialize the
array with if the loading fails. *)
{w, h : int} {p : addr}
(FILEref, !pixmap (a?, w, h, p) >> pixmap (a, w, h, p), a) ->
bool (* success *)
fn {a : t@ype}
pixmap$pixels_load :
(* A function that the reads n pixels from an input stream. (It
could be one pixel, it could be the entire image. From the user's
standpoint, it makes no difference. It is an implementation
detail HOW the function is called by pixmap_load.) *)
{n : int}
(FILEref, &array (a?, n) >> array (a, n), size_t n, a) ->
bool (* success *)
overload pixmap_make with pixmap_make_array
overload pixmap_make with pixmap_make_uninitized
overload pixmap_make with pixmap_make_elt
overload pixmap_free with pixmap_free_storage_return
overload pixmap_free with pixmap_free_storage_free
overload free with pixmap_free_storage_free
overload fill with pixmap_fill_elt
overload pixmap_set_at with pixmap_set_at_guint
overload pixmap_set_at with pixmap_set_at_gint
overload [] with pixmap_set_at
overload pixmap_get_at with pixmap_get_at_guint
overload pixmap_get_at with pixmap_get_at_gint
overload [] with pixmap_get_at
overload dump with pixmap_dump
overload load with pixmap_load
overload width with pixmap_width
overload height with pixmap_height
(*------------------------------------------------------------------*)
(* Here is a type for 24-bit RGB data. An RGB pixmap type thus can be
written as "pixmap (rgb24, w, h, p)".
There are, though you cannot see it here (they are in the dynamic
file), default implementations of pixmap$pixels_dump<rgb24> and
pixmap$pixels_load<rgb24>. These implementations are for dumping
raw data in PPM format. *)
(* It is an abstract type, the size of a triple of uint8. (It is, in
fact, a triple of uint8, but we hide this fact, so the template
system will not confuse the type with other triples of uint8. It is
a subtle matter. *)
abst@ype rgb24 = @(uint8, uint8, uint8)
fn {tk : tkind}
rgb24_make_uint_uint_uint :
(g0uint tk, g0uint tk, g0uint tk) -<> rgb24
fn {tk : tkind}
rgb24_make_int_int_int :
(g0int tk, g0int tk, g0int tk) -<> rgb24
fn {}
rgb24_make_tuple : @(uint8, uint8, uint8) -<> rgb24
fn {}
rgb24_values : rgb24 -<> @(uint8, uint8, uint8)
overload rgb24_make with rgb24_make_uint_uint_uint
overload rgb24_make with rgb24_make_int_int_int
overload rgb24_make with rgb24_make_tuple
(*------------------------------------------------------------------*)The ATS dynamic file
This file should be called bitmap_task.dats.
(*------------------------------------------------------------------*)
#define ATS_DYNLOADFLAG 0
#define ATS_PACKNAME "Rosetta_Code.bitmap_task"
#include "share/atspre_staload.hats"
staload "bitmap_task.sats"
(*------------------------------------------------------------------*)
(* The actual type, normally not seen by the user, is a boxed
record. *)
datavtype _pixmap (a : t@ype, w : int, h : int, p : addr) =
| _pixmap of
@{
pf = array_v (a, p, w * h) |
w = size_t w,
h = size_t h,
p = ptr p
}
(* Here is one of the ways to tie an abstract type to its
implementation: *)
assume pixmap (a, w, h, p) = _pixmap (a, w, h, p)
(* Another way is to use casts. *)
(*------------------------------------------------------------------*)
implement {}
pixmap_width pix =
case+ pix of _pixmap record => record.w
implement {}
pixmap_height pix =
case+ pix of _pixmap record => record.h
implement {a}
pixmap_make_array (pf | w, h, p) =
_pixmap @{pf = pf | w = w, h = h, p = p}
implement {a}
pixmap_unmake pix =
case+ pix of
| ~ _pixmap @{pf = pf | w = w, h = h, p = p} => @(pf | w, h, p)
primplement
pixmap_prove_index_bounds {w, h} {x, y} () =
let
prval () = mul_gte_gte_gte {y, w} ()
prval () = mul_gte_gte_gte {h - (y + 1), w} ()
in
end
implement {a}
pixmap_make_uninitized {w, h} (w, h) =
let
prval () = lemma_g1uint_param w (* Proves w >= 0. *)
prval () = lemma_g1uint_param h (* Proves h >= 0. *)
prval () = mul_gte_gte_gte {w, h} () (* Proves w*h >= 0. *)
val @(pf, pfgc | p) = array_ptr_alloc<a> (w * h)
val pix = pixmap_make<a?> (pf | w, h, p)
in
@(pfgc | pix)
end
implement {a}
pixmap_make_elt (w, h, elt) =
let
val @(pfgc | pix) = pixmap_make<a> (w, h)
in
fill<a> (pix, elt);
@(pfgc | pix)
end
implement {}
pixmap_free_storage_return pix =
case+ pix of
| ~ _pixmap record => @(record.pf | record.p)
implement {}
pixmap_free_storage_free (pfgc | pix) =
let
val @(pf | p) = pixmap_free pix
in
array_ptr_free (pf, pfgc | p)
end
implement {a}
pixmap_fill_elt {w, h} {p} (pix, elt) =
case+ pix of
| @ _pixmap record =>
let
prval () = lemma_g1uint_param (record.w)
prval () = lemma_g1uint_param (record.h)
prval () = mul_gte_gte_gte {w, h} ()
stadef n = w * h
val n : size_t n = record.w * record.h
and p : ptr p = record.p
fun
loop {i : nat | i <= n}
.<n - i>.
(pf_lft : array_v (a, p, i),
pf_rgt : array_v (a?, p + (i * sizeof a), n - i) |
i : size_t i)
: @(array_v (a, p, n) | ) =
if i = n then
let
prval () = array_v_unnil pf_rgt
in
@(pf_lft | )
end
else
let
prval @(pf_elt, pf_rgt) = array_v_uncons pf_rgt
val () = ptr_set<a> (pf_elt | ptr_add<a> (p, i), elt)
prval pf_lft = array_v_extend (pf_lft, pf_elt)
in
loop (pf_lft, pf_rgt | succ i)
end
val @(pf | ) = loop (array_v_nil (), record.pf | i2sz 0)
prval () = record.pf := pf
prval () = fold@ pix
in
end
implement {a} {tk}
pixmap_set_at_guint {w, h} {x, y} (pix, x, y, elt) =
case+ pix of
| @ _pixmap record =>
let
prval () = lemma_g1uint_param x
prval () = lemma_g1uint_param y
stadef n = w * h
stadef i = x + (y * w)
prval () = pixmap_prove_index_bounds {w, h} {x, y} ()
prval () = prop_verify {0 <= i && i < n} ()
(* I purposely store the data in an order such that you can
write something such as a PPM without looping separately
over x and y. Also, even if you did do an outer loop over y
and an inner loop over x, you would get the advantage of
data locality. *)
val i : size_t i = g1u2u x + (g1u2u y * record.w)
macdef pixels = !(record.p)
val () = pixels[i] := elt
prval () = fold@ pix
in
end
implement {a} {tk}
pixmap_set_at_gint (pix, x, y, elt) =
pixmap_set_at_guint<a><sizeknd> (pix, g1i2u x, g1i2u y, elt)
implement {a} {tk}
pixmap_get_at_guint {w, h} {x, y} (pix, x, y) =
case+ pix of
| @ _pixmap record =>
let
prval () = lemma_g1uint_param x
prval () = lemma_g1uint_param y
stadef n = w * h
stadef i = x + (y * w)
prval () = pixmap_prove_index_bounds {w, h} {x, y} ()
prval () = prop_verify {0 <= i && i < n} ()
val i : size_t i = g1u2u x + (g1u2u y * record.w)
macdef pixels = !(record.p)
val elt = pixels[i]
prval () = fold@ pix
in
elt
end
implement {a} {tk}
pixmap_get_at_gint (pix, x, y) =
pixmap_get_at_guint<a><sizeknd> (pix, g1i2u x, g1i2u y)
implement {a}
pixmap_dump (outf, pix) =
case+ pix of
| @ _pixmap record =>
let
macdef pixels = !(record.p)
val n = record.w * record.h
val success = pixmap$pixels_dump<a> (outf, pixels, n)
prval () = fold@ pix
in
success
end
implement {a}
pixmap_load (inpf, pix, elt) =
case+ pix of
| @ _pixmap record =>
let
macdef pixels = !(record.p)
val n = record.w * record.h
val success = pixmap$pixels_load<a> (inpf, pixels, n, elt)
prval () = fold@ pix
in
success
end
(*------------------------------------------------------------------*)
typedef FILEstar = $extype"FILE *"
extern castfn FILEref2star : FILEref -<> FILEstar
implement
pixmap$pixels_dump<rgb24> (outf, pixels, n) =
let
val num_written =
$extfcall (size_t, "fwrite", addr@ pixels, sizeof<rgb24>, n,
FILEref2star outf)
in
num_written = n
end
implement
pixmap$pixels_load<rgb24> (inpf, pixels, n, elt) =
let
prval [n : int] EQINT () = eqint_make_guint n
val num_read =
$extfcall (size_t, "fread", addr@ pixels, sizeof<rgb24>, n,
FILEref2star inpf)
in
if num_read = n then
let
prval () = $UNSAFE.castvwtp2void{@[rgb24][n]} pixels
in
true
end
else
begin
array_initize_elt<rgb24> (pixels, n, elt);
false
end
end
(*------------------------------------------------------------------*)
assume rgb24 = @(uint8, uint8, uint8)
implement {tk}
rgb24_make_uint_uint_uint (r, g, b) =
let
(* The prelude tends to miss implementations for type conversions
to uint8, so let us at least implement conversion from uint to
uint8. (I do not wish to use a general unsafe cast, because
that sort of code has caused me bugs before. C does not always
know how to do a type conversion correctly.) The ats2-xprelude
package has a much more complete set of implementations
(generated en masse by m4 macros), but for this task I am
avoiding such dependencies. *)
implement
g0uint2uint<uintknd,uint8knd> i =
let
extern castfn g0uint2uint_uint_uint8 : uint -<> uint8
in
g0uint2uint_uint_uint8 i
end
in
rgb24_make_tuple @(g0u2u r, g0u2u g, g0u2u b)
end
implement {tk}
rgb24_make_int_int_int (r, g, b) =
let
(* See the comment in rgb24_make_uint_uint_uint. *)
implement
g0int2uint<intknd,uint8knd> i =
let
extern castfn g0int2uint_int_uint8 : int -<> uint8
in
g0int2uint_int_uint8 i
end
in
rgb24_make @(g0i2u r, g0i2u g, g0i2u b)
end
implement {}
rgb24_make_tuple tup = tup
implement {}
rgb24_values rgb = rgb
(*------------------------------------------------------------------*)
#ifdef BITMAP_TASK_TEST #then
%{^
#include <limits.h>
%}
fn
test_sizeof_rgb24 () : void =
(* We want to be sure rgb24 takes up exactly 24 bits. Our dump and
load implementations depend on that. (If it prove not the case on
some platform, one can write, for that unanticipated platform,
special implementations of dump and load.) *)
let
val- true = sizeof<rgb24> = i2sz 3
val- true = sizeof<rgb24> * $extval (size_t, "CHAR_BIT") = i2sz 24
in
end
fn
test_pixel_load_copy_dump () : void =
(* Test loading, copying, and dumping of raw 24-bit RGB data from
SIPI image "Peppers", 4.2.07.tiff:
https://sipi.usc.edu/database/database.php?volume=misc&image=13#top
I have the data stored as "4.2.07.raw". *)
let
val failure_color = rgb24_make (0xFF, 0x00, 0x00)
val @(pfgc1 | pix1) = pixmap_make<rgb24> (i2sz 512, i2sz 512)
val inpf = fileref_open_exn ("4.2.07.raw", file_mode_r)
val success = load<rgb24> (inpf, pix1, failure_color)
val () = fileref_close inpf
val- true = success
val @(pfgc2 | pix2) = pixmap_make<rgb24> (i2sz 512, i2sz 512,
failure_color)
fun
copy_pixels {x, y : nat | x <= 512; y <= 512}
.<512 - x, 512 - y>.
(pix1 : !pixmap (rgb24, 512, 512),
pix2 : !pixmap (rgb24, 512, 512),
x : int x,
y : int y) : void =
if x = 512 then
()
else if y = 512 then
copy_pixels (pix1, pix2, succ x, 0)
else
begin
pix2[x, y] := pix1[x, y];
copy_pixels (pix1, pix2, x, succ y)
end
val () = copy_pixels (pix1, pix2, 0, 0)
val outf = fileref_open_exn ("4.2.07.raw.dumped", file_mode_w)
val success = dump<rgb24> (outf, pix2)
val () = fileref_close outf
val- true = success
val status = $extfcall (int, "system",
"cmp 4.2.07.raw 4.2.07.raw.dumped")
val- true = status = 0
in
free (pfgc1 | pix1);
free (pfgc2 | pix2)
end
implement
main0 () =
begin
test_sizeof_rgb24 ();
test_pixel_load_copy_dump ()
end
#endif
(*------------------------------------------------------------------*)A test can be run if one has a 786432-byte file and names it 4.2.07.raw. I used the raw data from a commonly used 512x512 test image. You can compile and run the test program thus:
$ patscc -std=gnu2x -g -O2 -DATS_MEMALLOC_LIBC -DATS BITMAP_TASK_TEST bitmap_task.sats bitmap_task.dats $ ./a.out
You should end up with a copy of the data in a file named 4.2.07.raw.dumped.
AutoHotkey
test:
blue := color(0,0,255) ; rgb
cyan := color(0,255,255)
blue_square := Bitmap(10, 10, blue)
cyanppm := Bitmap(10, 10, cyan)
x := blue_square[4,4] ; get pixel(4,4)
msgbox % "blue: 4,4,R,G,B, RGB: " x.R ", " x.G ", " x.B ", " x.rgb()
blue_square[4,4] := cyan ; set pixel(4,4)
x := blue_square[4,4] ; get pixel(4,4)
blue_square.write("blue.ppm")
return
Bitmap(width = 1, height = 1, background = 0)
{
global black
black := color(0,0,0)
if !background
background := black
static BitmapType
if !BitmapType
BitmapType
:= Object("fill", "Bitmap_Fill"
,"write", "Bitmap_write_ppm3")
img := Object("width", width
,"height", height
, "base" , BitmapType)
img._SetCapacity(height) ; an array of rows
img.fill(background)
Return img
}
Bitmap_Fill(bitmap, color)
{
r := color.r
g := color.g
b := color.b
loop % bitmap.height
{
height := A_Index
loop % bitmap.width
{
width := A_Index
bitmap[height, width] := color(r, g, b)
}
}
return bitmap
}
Bitmap_write_ppm3(bitmap, filename)
{
file := FileOpen(filename, 0x11) ; utf-8, write
file.seek(0,0)
file.write("P3`n"
. bitmap.width . " " . bitmap.height . "`n"
. "255`n")
loop % bitmap.height
{
height := A_Index
loop % bitmap.width
{
width := A_Index
color := bitmap[height, width]
file.Write(color.R . " ")
file.Write(color.G . " ")
file.Write(color.B . " ")
}
file.write("`n")
}
file.close()
return 0
}
Color(r, g, b)
{
static ColorType
if !ColorType
ColorType
:= Object("rgb" , "Color_rgb")
return Object("r" , r, "g", g, "b", b
, "base" , ColorType)
; return Object("r" , r, "g", g, "b", b, "rgb", "Color_rgb")
}
Color_rgb(clr)
{
return clr.R << 16 | clr.G << 8 | clr.B
}
Axe
All of the functions specified in the task are built in to Axe. Note that bitmaps are always 96x64 black and white. Thus, since each pixel takes 1 bit, a complete bitmap is 768 bytes.
Two bitmaps can be masked together to create 3- and 4-color grayscale.
Buff(768)→Pic1
Fill(Pic1,768,255)
Pxl-Off(45,30,Pic1)
.Display the bitmap to demonstrate
Copy(Pic1)
DispGraph
Pause 4500
Disp pxl-Test(50,50,Pic1)▶Dec,iBASIC
BASIC256
graphsize 30,30
call fill(rgb(255,0,0))
call setpixel(10,10,rgb(0,255,255))
print "pixel 10,10 is " + pixel(10,10)
print "pixel 20,20 is " + pixel(20,10)
imgsave "BASIC256_bitmap.png"
end
subroutine fill(c)
color c
rect 0,0,graphwidth, graphheight
end subroutine
subroutine setpixel(x,y,c)
color c
plot x,y
end subroutine- Output:
pixel 10,10 is 4278255615 pixel 20,20 is 4294901760
BBC BASIC
BBC BASIC expects a bitmap always to be associated with a window; for simplicity this code uses the main output window.
Width% = 200
Height% = 200
REM Set window size:
VDU 23,22,Width%;Height%;8,16,16,128
REM Fill with an RGB colour:
PROCfill(100,150,200)
REM Set a pixel:
PROCsetpixel(100,100,255,255,0)
REM Get a pixel:
rgb% = FNgetpixel(100,100)
PRINT RIGHT$("00000" + STR$~rgb%, 6)
END
DEF PROCfill(r%,g%,b%)
COLOUR 1,r%,g%,b%
GCOL 1+128
CLG
ENDPROC
DEF PROCsetpixel(x%,y%,r%,g%,b%)
COLOUR 1,r%,g%,b%
GCOL 1
LINE x%*2,y%*2,x%*2,y%*2
ENDPROC
DEF FNgetpixel(x%,y%)
LOCAL col%
col% = TINT(x%*2,y%*2)
SWAP ?^col%,?(^col%+2)
= col%
C
Working excerpt from imglib.h usable as "interface" (some includes are needed for other functions of the same category). This code uses functions from category Raster graphics operations. One must create files imglib.h and imglib.c using code from these pages. Start from bitmap page
#ifndef _IMGLIB_0
#define _IMGLIB_0
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <string.h>
#include <math.h>
#include <sys/queue.h>
typedef unsigned char color_component;
typedef color_component pixel[3];
typedef struct {
unsigned int width;
unsigned int height;
pixel * buf;
} image_t;
typedef image_t * image;
image alloc_img(unsigned int width, unsigned int height);
void free_img(image);
void fill_img(image img,
color_component r,
color_component g,
color_component b );
void put_pixel_unsafe(
image img,
unsigned int x,
unsigned int y,
color_component r,
color_component g,
color_component b );
void put_pixel_clip(
image img,
unsigned int x,
unsigned int y,
color_component r,
color_component g,
color_component b );
#define GET_PIXEL(IMG, X, Y) (IMG->buf[ ((Y) * IMG->width + (X)) ])
#endif
image alloc_img(unsigned int width, unsigned int height)
{
image img;
img = malloc(sizeof(image_t));
img->buf = malloc(width * height * sizeof(pixel));
img->width = width;
img->height = height;
return img;
}
void free_img(image img)
{
free(img->buf);
free(img);
}
void fill_img(
image img,
color_component r,
color_component g,
color_component b )
{
unsigned int i, n;
n = img->width * img->height;
for (i=0; i < n; ++i)
{
img->buf[i][0] = r;
img->buf[i][1] = g;
img->buf[i][2] = b;
}
}
void put_pixel_unsafe(
image img,
unsigned int x,
unsigned int y,
color_component r,
color_component g,
color_component b )
{
unsigned int ofs;
ofs = (y * img->width) + x;
img->buf[ofs][0] = r;
img->buf[ofs][1] = g;
img->buf[ofs][2] = b;
}
void put_pixel_clip(
image img,
unsigned int x,
unsigned int y,
color_component r,
color_component g,
color_component b )
{
if (x < img->width && y < img->height)
put_pixel_unsafe(img, x, y, r, g, b);
}
C#
This implementation uses a multidemensional array to store the Color structure (which stores the RGB values). No exception catching for out-of-bounds errors if they occur, but provides Height and Width properties so a program using it can avoid them.
public class Bitmap
{
public struct Color
{
public byte Red { get; set; }
public byte Blue { get; set; }
public byte Green { get; set; }
}
Color[,] _imagemap;
public int Width { get { return _imagemap.GetLength(0); } }
public int Height { get { return _imagemap.GetLength(1); } }
public Bitmap(int width, int height)
{
_imagemap = new Color[width, height];
}
public void Fill(Color color)
{
for (int y = 0; y < Height; y++)
for (int x = 0; x < Width; x++)
{
_imagemap[x, y] = color;
}
}
public Color GetPixel(int x, int y)
{
return _imagemap[x, y];
}
public void SetPixel(int x, int y, Color color)
{
_imagemap[x, y] = color;
}
}
C++
#include <iostream>
#include <boost/gil/gil_all.hpp>
int main()
{
using namespace boost::gil;
// create 30x40 image
rgb8_image_t img(30, 40);
// fill with red
rgb8_pixel_t red(255, 0, 0);
fill_pixels(view(img), red);
// set pixel at 10x20 to blue
rgb8_pixel_t blue(0, 0, 255);
view(img)(10, 20) = blue;
// read the value of pixel at 11x20
rgb8_pixel_t px = const_view(img)(11, 20);
std::cout << "the pixel at 11, 20 is " << (unsigned)px[0] << ':' << (unsigned)px[1] << ':' << (unsigned)px[2] << '\n';
}
See also Basic bitmap storage/C++
Clojure
(import '[java.awt Color Graphics Image]
'[java.awt.image BufferedImage])
(defn blank-bitmap [width height]
(BufferedImage. width height BufferedImage/TYPE_3BYTE_BGR))
(defn fill [image color]
(doto (.getGraphics image)
(.setColor color)
(.fillRect 0 0 (.getWidth image) (.getHeight image))))
(defn set-pixel [image x y color]
(.setRGB image x y (.getRGB color)))
(defn get-pixel [image x y]
(Color. (.getRGB image x y)))
Common Lisp
(defpackage #:rgb-pixel-buffer
(:use #:common-lisp)
(:export #:rgb-pixel-component #:rgb-pixel #:rgb-pixel-buffer
#:+red+ #:+green+ #:+blue+ #:+black+ #:+white+
#:make-rgb-pixel #:make-rgb-pixel-buffer #:rgb-pixel-buffer-width
#:rgb-pixel-buffer-height #:rgb-pixel-red #:rgb-pixel-green
#:rgb-pixel-blue #:fill-rgb-pixel-buffer))
(in-package #:rgb-pixel-buffer)
(deftype rgb-pixel-component ()
'(unsigned-byte 8))
(deftype rgb-pixel ()
'(unsigned-byte 24))
(deftype rgb-pixel-buffer (&optional (width '*) (height '*))
`(array rgb-pixel (,width ,height)))
(defconstant +black+ 0)
(defconstant +white+ #xFFFFFF)
(defconstant +red+ #xFF0000)
(defconstant +green+ #x00FF00)
(defconstant +blue+ #x0000FF)
(defun make-rgb-pixel (r g b)
(declare (type rgb-pixel-component r g b))
(logior (ash r 16) (ash g 8) b))
(defun rgb-pixel-red (rgb)
(declare (type rgb-pixel rgb))
(logand (ash rgb -16) #xFF))
(defun rgb-pixel-green (rgb)
(declare (type rgb-pixel rgb))
(logand (ash rgb -8) #xFF))
(defun rgb-pixel-blue (rgb)
(declare (type rgb-pixel rgb))
(logand rgb #xFF))
(defun make-rgb-pixel-buffer (width height &optional (initial-element +black+))
(declare (type (integer 1) width height))
(declare (type rgb-pixel initial-element))
(make-array (list width height)
:element-type 'rgb-pixel
:initial-element initial-element))
(defun rgb-pixel-buffer-width (buffer)
(first (array-dimensions buffer)))
(defun rgb-pixel-buffer-height (buffer)
(second (array-dimensions buffer)))
(defun rgb-pixel (buffer x y)
(declare (type rgb-pixel-buffer buffer))
(declare (type (integer 0) x y))
(aref buffer x y))
(defun (setf rgb-pixel) (value buffer x y)
(declare (type rgb-pixel-buffer buffer))
(declare (type rgb-pixel value))
(declare (type (integer 0) x y))
(setf (aref buffer x y) value))
(defun fill-rgb-pixel-buffer (buffer pixel)
(declare (type rgb-pixel-buffer buffer))
(declare (type rgb-pixel pixel))
(let* ((dimensions (array-dimensions buffer))
(width (first dimensions))
(height (second dimensions)))
(loop
:for y :of-type fixnum :upfrom 0 :below height
:do (loop
:for x :of-type fixnum :upfrom 0 :below width
:do (setf (rgb-pixel buffer x y) pixel)))
buffer))
Example:
(defvar *buffer* (make-rgb-pixel-buffer 10 10))
(fill-rgb-pixel-buffer *buffer* +white+)
(setf (rgb-pixel *buffer* 0 0) +red+)
(setf (rgb-pixel *buffer* 0 9) +red+)
(setf (rgb-pixel *buffer* 9 0) +red+)
(setf (rgb-pixel *buffer* 9 9) +red+)
Crystal
class RGBColor
getter red, green, blue
def initialize(@red = 0_u8, @green = 0_u8, @blue = 0_u8)
end
RED = new(red: 255_u8)
GREEN = new(green: 255_u8)
BLUE = new(blue: 255_u8)
BLACK = new
WHITE = new(255_u8, 255_u8, 255_u8)
end
class Pixmap
getter width, height
@data : Array(Array(RGBColor))
def initialize(@width : Int32, @height : Int32)
@data = Array.new(@width) { Array.new(@height, RGBColor::WHITE) }
end
def fill(color)
@data.each &.fill(color)
end
def [](x, y)
@data[x][y]
end
def []=(x, y, color)
@data[x][y] = color
end
end
bmap = Pixmap.new(5, 5)
pp bmap
D
This code is a little complex because many Tasks use this module for various purposes.
module bitmap;
import std.stdio, std.array, std.exception, std.string, std.conv,
std.algorithm, std.ascii;
final class Image(T) {
static if (is(typeof({ auto x = T.black; })))
const static T black = T.black;
else
const static T black = T.init;
static if (is(typeof({ auto x = T.white; })))
const static T white = T.white;
T[] image;
private size_t nx_, ny_;
this(in int nxx=0, in int nyy=0, in bool inizialize=true)
pure nothrow {
allocate(nxx, nyy, inizialize);
}
void allocate(in int nxx=0, in int nyy=0, in bool inizialize=true)
pure nothrow @safe in {
assert(nxx >= 0 && nyy >= 0);
} body {
this.nx_ = nxx;
this.ny_ = nyy;
if (nxx * nyy > 0) {
if (inizialize)
image.length = nxx * nyy;
else // Optimization.
image = minimallyInitializedArray!(typeof(image))
(nxx * nyy);
}
}
@property Image dup() const pure nothrow @safe {
auto result = new Image();
result.image = this.image.dup;
result.nx_ = this.nx;
result.ny_ = this.ny;
return result;
}
static Image fromData(T[] data, in size_t nxx=0, in size_t nyy=0)
pure nothrow @safe in {
assert(nxx >= 0 && nyy >= 0 && data.length == nxx * nyy);
} body {
auto result = new Image();
result.image = data;
result.nx_ = nxx;
result.ny_ = nyy;
return result;
}
@property size_t nx() const pure nothrow @safe @nogc { return nx_; }
@property size_t ny() const pure nothrow @safe @nogc { return ny_; }
ref T opIndex(in size_t x, in size_t y) pure nothrow @safe @nogc
in {
assert(x < nx_ && y < ny_);
//assert(x < nx_, format("opIndex, x=%d, nx=%d", x, nx));
//assert(y < ny_, format("opIndex, y=%d, ny=%d", y, ny));
} body {
return image[x + y * nx_];
}
T opIndex(in size_t x, in size_t y) const pure nothrow @safe @nogc
in {
assert(x < nx_ && y < ny_);
//assert(x < nx_, format("opIndex, x=%d, nx=%d", x, nx));
//assert(y < ny_, format("opIndex, y=%d, ny=%d", y, ny));
} body {
return image[x + y * nx_];
}
T opIndexAssign(in T color, in size_t x, in size_t y)
pure nothrow @safe @nogc
in {
assert(x < nx_ && y < ny_);
//assert(x < nx_, format("opIndex, x=%d, nx=%d", x, nx));
//assert(y < ny_, format("opIndex, y=%d, ny=%d", y, ny));
} body {
return image[x + y * nx_] = color;
}
void opIndexUnary(string op)(in size_t x, in size_t y)
pure nothrow @safe @nogc
if (op == "++" || op == "--") in {
assert(x < nx_ && y < ny_);
} body {
mixin("image[x + y * nx_] " ~ op ~ ";");
}
void clear(in T color=this.black) pure nothrow @safe @nogc {
image[] = color;
}
/// Convert a 2D array of chars to a binary Image.
static Image fromText(in string txt,
in char one='#', in char zero='.') pure {
auto M = txt
.strip
.split
.map!(row => row
.filter!(c => c == one || c == zero)
.map!(c => T(c == one))
.array)
.array;
assert(M.join.length > 0); // Not empty.
foreach (row; M)
assert(row.length == M[0].length); // Rectangular
return Image.fromData(M.join, M[0].length, M.length);
}
/// The axis origin is at the top left.
void textualShow(in char bl='#', in char wh='.') const nothrow {
size_t i = 0;
foreach (immutable y; 0 .. ny_) {
foreach (immutable x; 0 .. nx_)
putchar(image[i++] == black ? bl : wh);
putchar('\n');
}
}
}
struct RGB {
ubyte r, g, b;
static immutable black = typeof(this)();
static immutable white = typeof(this)(255, 255, 255);
}
Image!RGB loadPPM6(ref Image!RGB img, in string fileName) {
if (img is null)
img = new Image!RGB;
auto f = File(fileName, "rb");
enforce(f.readln.strip == "P6");
string line;
do {
line = f.readln();
} while (line.length && line[0] == '#'); // Skip comments.
const size = line.split;
enforce(size.length == 2);
img.allocate(size[0].to!uint, size[1].to!uint);
enforce(f.readln().strip() == "255");
auto l = new ubyte[img.nx * 3];
size_t i = 0;
foreach (immutable y; 0 .. img.ny) {
f.rawRead!ubyte(l);
foreach (immutable x; 0 .. img.nx)
img.image[i++] = RGB(l[x * 3], l[x * 3 + 1], l[x * 3 + 2]);
}
return img;
}
void savePPM6(in Image!RGB img, in string fileName)
in {
assert(img !is null);
assert(img.nx > 0 && img.nx > 0);
} body {
auto f = File(fileName, "wb");
f.writefln("P6\n%d %d\n255", img.nx, img.ny);
size_t i = 0;
foreach (immutable y; 0 .. img.ny)
foreach (immutable x; 0 .. img.nx) {
immutable p = img.image[i++];
f.write(cast(char)p.r, cast(char)p.g, cast(char)p.b);
}
}
version (bitmap_main) {
void main() {
auto img = new Image!RGB(30, 10);
img[4, 5] = RGB.white;
img.textualShow;
}
}
Compiling it with version=bitmap_main prints:
- Output:
############################## ############################## ############################## ############################## ############################## ####.######################### ############################## ############################## ############################## ##############################
Delphi
program BitmapTest;
{$APPTYPE CONSOLE}
type
TColor = record
private
function GetColor: Cardinal;
procedure SetColor(const Value: Cardinal);
public
Red, Green, Blue, Alpha: Byte;
property Color: Cardinal read GetColor write SetColor;
end;
TBitmap = class
private
FPixels: array of array of TColor;
FHeight: Integer;
FWidth: Integer;
function GetPixel(X, Y: integer): TColor;
public
procedure Fill(aColor: TColor); overload;
procedure Fill(aColor: Cardinal); overload;
procedure SetSize(w, h: Integer);
constructor Create(); overload;
constructor Create(w, h: Integer); overload;
property Height: Integer read FHeight;
property Width: Integer read FWidth;
property Pixel[X, Y: integer]: TColor read GetPixel;
end;
{ TColor }
function TColor.GetColor: Cardinal;
begin
Result := (alpha shl 24) + (red shl 16) + (green shl 8) + blue;
end;
procedure TColor.SetColor(const Value: Cardinal);
begin
blue := (Value and $FF);
green := ((Value shr 8) and $FF);
red := ((Value shr 16) and $FF);
alpha := ((Value shr 24) and $FF);
end;
{ TBitmap }
constructor TBitmap.Create;
begin
inherited;
FHeight := 0;
FWidth := 0;
end;
constructor TBitmap.Create(w, h: Integer);
begin
Create;
SetSize(w, h);
end;
procedure TBitmap.Fill(aColor: Cardinal);
var
x, y: Integer;
begin
if (Width > 0) and (Height > 0) then
for x := 0 to width - 1 do
for y := 0 to height - 1 do
FPixels[x, y].Color := aColor;
end;
procedure TBitmap.Fill(aColor: TColor);
begin
Fill(aColor.Color);
end;
function TBitmap.GetPixel(X, Y: integer): TColor;
begin
Result := FPixels[X, Y];
end;
procedure TBitmap.SetSize(w, h: Integer);
var
i: Integer;
begin
if (h = 0) or (w = 0) then
begin
h := 0;
w := 0;
end;
FHeight := h;
FWidth := w;
SetLength(FPixels, w);
if w > 0 then
for i := 0 to w - 1 do
SetLength(FPixels[i], h);
end;
var
bmp: TBitmap;
x, y: Integer;
begin
bmp := TBitmap.Create(200, 200);
bmp.Fill($00FF0000);
for y := 0 to bmp.Height - 1 do
for x := 0 to bmp.Width - 1 do
begin
if x mod 2 = 1 then
bmp.Pixel[x, y].Color := $0000FF;
end;
bmp.Free;
end.
Delphi
This is a pure Delphi example using standard Delphi controls and libraries that already have raster and bitmap objects and operations built in.
Bascially, Delphi has a powerful set of tools for manipulating graphic objects. All graphic objects including Screens, Printers, Windows or Bitmaps, have a property called a "Canvas." As a consequence, the same code can draw on the Screen, the Printer, a Window or a Bitmap. A Canvas has powerful function that allow you to draw pixels, lines, rectangles, circles, elispes, polygons and text on any graphic object. The code below demonstrates many of the function available in a canvas.
procedure ShowBitmapFunctions(Image: TImage);
{Code to demonstrate some of the main features the Delphi "TCanvas" object}
var I,X,Y: integer;
var C: TColor;
begin
{Draw red rectangle with 3 pixels wide lines}
Image.Canvas.Pen.Color:=clRed;
Image.Canvas.Pen.Width:=3;
Image.Canvas.Rectangle(50,50,500,300);
{Flood fill rectangle blue}
Image.Canvas.Brush.Color:=clBlue;
Image.Canvas.FloodFill(55,55,clRed,fsBorder);
{Draw random dots on the screen}
for I:=1 to 1000 do
begin
X:=trunc((Random * 450) + 50);
Y:=trunc((Random * 250) + 50);
C:=RGB(Random(255),Random(255),Random(255));
{draw 9 pixels for each point to make dots more visible}
Image.Canvas.Pixels[X-1,Y-1]:=C;
Image.Canvas.Pixels[X ,Y-1]:=C;
Image.Canvas.Pixels[X+1,Y-1]:=C;
Image.Canvas.Pixels[X-1,Y ]:=C;
Image.Canvas.Pixels[X ,Y ]:=C;
Image.Canvas.Pixels[X+1,Y ]:=C;
Image.Canvas.Pixels[X-1,Y+1]:=C;
Image.Canvas.Pixels[X ,Y+1]:=C;
Image.Canvas.Pixels[X+1,Y+1]:=C;
end;
{Draw lime-green line from corner to cornder}
Image.Canvas.Pen.Color:=clLime;
Image.Canvas.MoveTo(50,50);
Image.Canvas.LineTo(500,300);
{Sample pixel color at 51,51}
C:=Image.Canvas.Pixels[51,51];
{Display the color value }
Image.Canvas.Brush.Color:=clAqua;
Image.Canvas.Font.Size:=25;
Image.Canvas.Font.Color:=clRed;
Image.Canvas.TextOut(5,5,IntToHex(C,8));
{Tell Delphi to update the Window}
Image.Repaint;
end;
- Output:
Elapsed Time: 39.038 ms.
E
This example includes the write ppm file code, because it is most naturally written as a method on the image object.
def makeFlexList := <elib:tables.makeFlexList>
def format := <import:java.lang.makeString>.format
def CHANNELS := 3
def UByte := 0..255
def makeColor {
to fromFloat(r, g, b) {
return makeColor.fromByte((r * 255).round(),
(g * 255).round(),
(b * 255).round())
}
to fromByte(r :UByte, g :UByte, b :UByte) {
def color {
to __printOn(out) {
out.print(format("%02x%02x%02x", [color.rb(), color.gb(), color.bb()]))
}
to rf() { return r / 255 }
to gf() { return g / 255 }
to bf() { return b / 255 }
to rb() { return r }
to gb() { return g }
to bb() { return b }
}
return color
}
}
/** Convert 0..255 into 0..127 -128..-1 */
def sign(v) {
return v %% 256 - 2*(v & 128)
}
def makeImage(width, height) {
# NOTE: The primary E implementation is in Java and Java's fixed-size integers only
# come in signed varieties. Therefore, there is a little bit of extra arithmetic.
#
# In an ideal E implementation we would specify the type 0..255, but this is not
# currently possible everywhere, or efficient.
def storage := makeFlexList.fromType(<type:java.lang.Byte>, width * height * CHANNELS)
storage.setSize(width * height * CHANNELS)
def X := 0..!width
def Y := 0..!height
def flexImage {
to __printOn(out) {
for y in Y {
out.print("[")
for x in X {
out.print(flexImage[x, y], " ")
}
out.println("]")
}
}
to width() { return width }
to height() { return height }
to fill(color) {
for x in X {
for y in Y {
flexImage[x, y] := color
}
}
}
to get(x :X, y :Y) {
def base := (y * width + x) * CHANNELS
return makeColor.fromByte(storage[base + 0] %% 256,
storage[base + 1] %% 256,
storage[base + 2] %% 256)
}
/** Provided to make [[Flood fill]] slightly less insanely slow. */
to test(x :X, y :Y, c) {
def base := (y * width + x) * CHANNELS
return storage[base + 0] <=> sign(c.rb()) &&
storage[base + 1] <=> sign(c.gb()) &&
storage[base + 2] <=> sign(c.bb())
}
to put(x :X, y :Y, c) {
def base := (y * width + x) * CHANNELS
storage[base + 0] := sign(c.rb())
storage[base + 1] := sign(c.gb())
storage[base + 2] := sign(c.bb())
}
to writePPM(outputStream) {
outputStream.write(`P6$\n$width $height$\n255$\n`.getBytes("US-ASCII"))
outputStream.write(storage.getArray())
}
/** Used for [[Read ppm file]] */
to replace(list :List) {
require(list.size() == width * height * CHANNELS)
storage(0) := list
}
}
return flexImage
}Examples/tests:
? def i := makeImage(3, 3)
# value: [000000 000000 000000 ]
# [000000 000000 000000 ]
# [000000 000000 000000 ]
#
? i.fill(makeColor.fromFloat(1, 0, 0))
? i
# value: [ff0000 ff0000 ff0000 ]
# [ff0000 ff0000 ff0000 ]
# [ff0000 ff0000 ff0000 ]
#
? i[1, 1] := makeColor.fromFloat(0.5, 0.5, 0.5)
# value: 808080
? i
# value: [ff0000 ff0000 ff0000 ]
# [ff0000 808080 ff0000 ]
# [ff0000 ff0000 ff0000 ]
#
? i[0, 1]
# value: ff0000
? i[1, 1]
# value: 808080
? i.writePPM(<import:java.io.makeFileOutputStream>(<file:~/Desktop/Rosetta.ppm>))EchoLisp
(lib 'plot)
(define width 600)
(define height 400)
(plot-size width height) ;; set image size
(define (blue x y) (rgb 0.0 0.0 1.0)) ;; a constant function
(plot-rgb blue 1 1) ;; blue everywhere
(lib 'types) ;; uint32 and uint8 vector types
;; bit-map pixel access
(define bitmap (pixels->uint32-vector)) ;; screen to vector of int32
→ 240000
(define (pix-at x y) (vector-ref bitmap (+ x (* y width))))
(rgb->list (pix-at 100 200)) → (0 0 255 255) ;; rgb blue
;; writing to bitmap
(define (set-color-xy x y col) (vector-set! bitmap (+ x (* y width)) col))
(for* ((x 100)(y 200)) (set-color-xy x y (rgb 1 1 0))) ;; to bitmap
(vector->pixels bitmap) ;; bitmap to screen
;; bit-map color components (r g b a) = index (0 1 2 3) access
(define bitmap (pixels->uint8-clamped-vector)) ;; screen to vector of uint8
(vector-length bitmap)
→ 960000
(define (blue-at-xy x y) (vector-ref bitmap (+ x 3 (* y width)))) ;; 3 = blue component
(blue-at-xy 100 200)
→ 255
Elixir
Translation of the erlang version of the code.
defmodule RosBitmap do
defrecord Bitmap, pixels: nil, shape: {0, 0}
defp new(width, height, {:rgb, r, g, b}) do
Bitmap[
pixels: :array.new(width * height,
{:default, <<r::size(8), g::size(8), b::size(8)>>}),
shape: {width, height}]
end
def new(width, height), do: new(width, height, {:rgb, 0, 0, 0})
def fill(Bitmap[shape: {width, height}], {:rgb, _r, _g, _b}=color) do
new(width, height, color)
end
def set_pixel(Bitmap[pixels: pixels, shape: {width, _height}]=bitmap,
{:at, x, y}, {:rgb, r, g, b}) do
index = x + y * width
bitmap.pixels(:array.set(index, <<r::size(8), g::size(8), b::size(8)>>, pixels))
end
def get_pixel(Bitmap[pixels: pixels, shape: {width, _height}], {:at, x, y}) do
index = x + y * width
<<r::size(8), g::size(8), b::size(8)>> = :array.get(index, pixels)
{:rgb, r, g, b}
end
end
Erlang
Stores pixels as a 1d array and colors as binaries.
-module(ros_bitmap).
-export([new/2, fill/2, set_pixel/3, get_pixel/2]).
-record(bitmap, {
pixels = nil,
shape = {0, 0}
}).
new(Width, Height) ->
#bitmap{pixels=array:new(Width * Height, {default, <<0:8, 0:8, 0:8>>}), shape={Width, Height}}.
fill(#bitmap{shape={Width, Height}}, {rgb, R, G, B}) ->
#bitmap{
pixels=array:new(Width * Height, {default, <<R:8, G:8, B:8>>}),
shape={Width, Height}}.
set_pixel(#bitmap{pixels=Pixels, shape={Width, _Height}}=Bitmap, {at, X, Y}, {rgb, R, G, B}) ->
Index = X + Y * Width,
Bitmap#bitmap{pixels=array:set(Index, <<R:8, G:8, B:8>>, Pixels)}.
get_pixel(#bitmap{pixels=Pixels, shape={Width, _Height}}, {at, X, Y}) ->
Index = X + Y * Width,
<<R:8, G:8, B:8>> = array:get(Index, Pixels),
{rgb, R, G, B}.
Euphoria
-- Some color constants:
constant
black = #000000,
white = #FFFFFF,
red = #FF0000,
green = #00FF00,
blue = #0000FF
-- Create new image filled with some color
function new_image(integer width, integer height, atom fill_color)
return repeat(repeat(fill_color,height),width)
end function
-- Usage example:
sequence image
image = new_image(800,600,black)
-- Set pixel color:
image[400][300] = red
-- Get pixel color
atom color
color = image[400][300] -- Now color is #FF0000?color -- Should print out 16711680
F#
FSharp can accomplish this task in several ways. This version is purely functional. The bitmap data structure does not mutate. Set pixel, for example, simply transforms the input bitmap into a new bitmap with that pixel set to the input color. If you have Framework 4.5, you can use ImmutableArray to force this immutability.
Solution:
//pure functional version ... changing a pixel color provides a new Bitmap
type Color = {red: byte; green: byte; blue: byte}
type Point = {x:uint32; y:uint32}
type Bitmap = {color: Color array; maxX: uint32; maxY: uint32}
let colorBlack = {red = (byte) 0; green = (byte) 0; blue = (byte) 0}
let emptyBitmap = {color = Array.empty; maxX = (uint32) 0; maxY = (uint32) 0}
let bitmap (width: uint32) (height: uint32) =
match width, height with
| 0u,0u | 0u,_ | _, 0u -> emptyBitmap
| _,_ -> {color = Array.create ((int) (width * height)) colorBlack;
maxX = width;
maxY = height}
let getPixel point bitmap =
match bitmap.color with
| c when c |> Array.isEmpty -> None
| c when (uint32) c.Length <= (point.y * bitmap.maxY + point.x) -> None
| c -> Some c.[(int) (point.y * bitmap.maxY + point.x)]
let setPixel point color bitmap =
{bitmap with color = bitmap.color |> Array.mapi (function
| i when i = (int) (point.y * bitmap.maxY + point.x) ->
(fun _ -> color)
| _ -> id)}
let fill color bitmap = {bitmap with color = bitmap.color |> Array.map (fun _ ->color)}
Tests:
//setups
//==check pixel for color function
let check bitmap color (x,y) =
match (getPixel {x=x;y=y} bitmap) with
| Some(v) -> v = color
| _ -> false
let allPixels i j = [for x in [0u..(i-1u)] do for y in [0u..(j-1u)] -> (x,y)]
//create new empty bitmap
let myBitmap = bitmap 0u 0u
printfn "Is empty: %b" (myBitmap = emptyBitmap)
let myBitmap2 = bitmap 1u 0u
printfn "Is empty: %b" (myBitmap2 = emptyBitmap)
let myBitmap3 = bitmap 0u 1u
printfn "Is empty: %b" (myBitmap3 = emptyBitmap)
//create normal bitmap
let myBitmap4 = bitmap 14u 14u
printfn "Is not empty: %b" (not (myBitmap4 = emptyBitmap))
//just check one color
printfn "Is 1,1 black: %b" (check myBitmap4 colorBlack (1u,1u))
//check out of range color
printfn "Is 100,100 nothing: %b" (not(check myBitmap4 colorBlack (100u,100u)))
//make sure all pixels are black
printfn "Is all black: %b" ((allPixels 14u 14u) |> List.forall (check myBitmap4 colorBlack))
//fill bitmap color
let colorWhite = {red = (byte) 255; green = (byte) 255; blue = (byte) 255}
let myBitmap5 = myBitmap4 |> fill colorWhite
printfn "Is all white: %b" ((allPixels 14u 14u) |> List.forall (check myBitmap5 colorWhite))
//change just one pixel
let myBitmap6 = myBitmap5 |> setPixel {x=5u;y=10u} colorBlack
printfn "Is 5,10 black: %b" (check myBitmap4 colorBlack (5u,10u))
- Output:
Is empty
Is empty: true
Is empty: true
Is not empty: true
Is 1,1 black: true
Is 100,100 nothing: true
Is all black: true
Is all white: true
Is 5,10 black: true Usage:
bitmap 14u 14u
|> fill {red = (byte) 200; green = (byte) 0; blue = (byte) 10}
|> setPixel {x=5u;y=10u} {red = (byte) 0; green = (byte) 0; blue = (byte) 0}
|> getPixel {x=5u;y=10u}
|> printfn "%A"
- Output:
Some {red = 0uy;
green = 0uy;
blue = 0uy;}
Factor
The image is a matrix of triples {R,G,B}. The various utilities could be defined in another file, most of them are not used right now, but we need them for drawing so I put every thing here..
USING: arrays fry kernel math.matrices sequences ;
IN: rosettacode.raster.storage
! Various utilities
: meach ( matrix quot -- ) [ each ] curry each ; inline
: meach-index ( matrix quot -- )
[ swap 2array ] prepose
[ curry each-index ] curry each-index ; inline
: mmap ( matrix quot -- matrix' ) [ map ] curry map ; inline
: mmap! ( matrix quot -- matrix' ) [ map! ] curry map! ; inline
: mmap-index ( matrix quot -- matrix' )
[ swap 2array ] prepose
[ curry map-index ] curry map-index ; inline
: matrix-dim ( matrix -- i j ) [ length ] [ first length ] bi ;
: set-Mi,j ( elt {i,j} matrix -- ) [ first2 swap ] dip nth set-nth ;
: Mi,j ( {i,j} matrix -- elt ) [ first2 swap ] dip nth nth ;
! The storage functions
: <raster-image> ( width height -- image )
zero-matrix [ drop { 0 0 0 } ] mmap ;
: fill-image ( {R,G,B} image -- image )
swap '[ drop _ ] mmap! ;
: set-pixel ( {R,G,B} {i,j} image -- ) set-Mi,j ; inline
: get-pixel ( {i,j} image -- pixel ) Mi,j ; inline
FBSL
Volatility in FBSL is a feature uncommon to most other languages. It is the ability of its intrinsic functions as well as its user-defined functions, DynAsm and DynC blocks, and functions imported from 3rd-party DLL's to preserve their return values between function calls in FBSL Variants that have the same names as their respective functions but use neither the parentheses nor the arguments. These Variants belong to the global namespace and can be used throughout the entire script until another fully qualified function call to their respective functions is made, whereby they change their values accordingly. The feature minimizes the need for temporary variables and assignments.
This feature is a logical extension of VisualBasic way to formalize its function return value by assigning it to a Variant of the same name as that of the respective function. However, the VB Variant is only effective within the scope of its own function.
Using pure FBSL's built-in graphics functions:
#DEFINE WM_LBUTTONDOWN 513
#DEFINE WM_RBUTTONDOWN 516
#DEFINE WM_CLOSE 16
FBSLSETFORMCOLOR(ME, RGB(0, 255, 255)) ' Cyan: set persistent background color
DRAWWIDTH(5) ' Adjust point size
FBSL.GETDC(ME) ' Use volatile FBSL.GETDC below to avoid extra assignments
RESIZE(ME, 0, 0, 300, 200)
CENTER(ME)
SHOW(ME)
BEGIN EVENTS
SELECT CASE CBMSG
CASE WM_LBUTTONDOWN ' Set color at current coords as hex literal
PSET(FBSL.GETDC, LOWORD(CBLPARAM), HIWORD(CBLPARAM), &H0000FF) ' Red: Windows stores colors in BGR order
CASE WM_RBUTTONDOWN ' Get color at current coords as hex literal
FBSLSETTEXT(ME, "&H" & HEX(POINT(FBSL.GETDC, LOWORD(CBLPARAM), HIWORD(CBLPARAM))))
CASE WM_CLOSE ' Clean up
FBSL.RELEASEDC(ME, FBSL.GETDC)
END SELECT
END EVENTS
- Output:
Forth
This creates bitmaps on the heap (they may be deallocated with "FREE"). 32-bit or greater cells are assumed, one pixel per cell. This automatically word-aligns rows, so a separate stride field is not required.
hex
0000ff constant red
00ff00 constant green
ff0000 constant blue
decimal
1 cells constant pixel
: pixels cells ;
: bdim ( bmp -- w h ) 2@ ;
: bheight ( bmp -- h ) @ ;
: bwidth ( bmp -- w ) bdim drop ;
: bdata ( bmp -- addr ) 2 cells + ;
: bitmap ( w h -- bmp )
2dup * pixels bdata allocate throw
dup >r 2! r> ;
: bfill ( pixel bmp -- )
dup bdata swap bdim * pixels
bounds do
dup i !
pixel +loop
drop ;
: bxy ( x y bmp -- addr )
dup >r bwidth * + pixels r> bdata + ;
: b@ ( x y bmp -- pixel ) bxy @ ;
: b! ( pixel x y bmp -- ) bxy ! ;
: bshow ( bmp -- )
hex
dup bdim
0 do cr
dup 0 do
over i j rot b@ if [char] * else bl then emit \ 7 u.r
loop
loop
2drop decimal ;
4 3 bitmap value test
red test bfill
test bshow cr
Fortran
See Basic bitmap storage/Fortran
FreeBASIC
Screenres 320, 240, 8
Dim Shared As Integer w, h
Screeninfo w, h
Const As Ubyte cyan = 3
Const As Ubyte red = 4
Sub rellenar(c As Integer)
Line (0,0) - (w/3, h/3), red, BF
End Sub
Sub establecePixel(x As Integer, y As Integer, c As Integer)
Pset (x,y), cyan
End Sub
rellenar(12)
establecePixel(10,10, cyan)
Locate 12
Print "pixel 10,10 es " & Point(10,10)
Print "pixel 20,20 es " & Point(20,10)
Bsave "FreeBASIC_bitmap.bmp", 0
Sleep
FutureBasic
include "NSLog.incl"
/*
This task creates an image with a background filled with red pixels.
Then sets one pixel to blue in the center of the image.
Then gets the RGB color values at that pixel position.
Then saves the image as a jpg to the desktop.
*/
_Window = 1
_Horz = 300
_Vert = 100
_X = 150
_Y = 50
window _Window, @"Bitmap window with blue dot",(0,0,_Horz, _Vert)
WindowSetBackgroundColor(_Window,fn colorwhite)
local fn DrawImage as ImageRef
ImageRef image = fn ImageWithSize( fn CGSizeMake(_Horz,_Vert ) ) // create blank image
ImageLockFocus( image ) // lock image during drawing
CFIndex i
for i = 0 to _Horz // fill all horizontal pixels with red dots
BezierPathStrokeLine( fn CGPointMake( i, 0 ), fn CGPointMake( i, _Vert ), 1, fn Colorred )
next
BezierPathStrokeRect( fn CGRectMake( _X,_Y,1,1), 1.0, fn ColorBlue) // Draw a blue dot in the center.
ImageUnlockFocus( image ) // unlock image afer drawing
end fn = image
// Draw the image
ImageRef theImage
theImage = fn DrawImage
// Display the image
imageview 1,, theImage, (0,0,_Horz, _Vert)
// Get the color of the pixel at horizontal position X and vertical position Y
colorref color
color = fn ViewColorAtXY( _Window, _X, _Y )
NSLog( @"RGB Color values at pixel position X,Y are %@", color)
// Save the image as a jpg
CFURLRef DesktopDirectory,url
DesktopDirectory = fn FileManagerURLForDirectory( NSDesktopDirectory, NSUserDomainMask )
url = fn URLByAppendingPathComponent( DesktopDirectory, @"Bitmap Image.jpg" )
bool err
err = fn ImageWriteToURL( theImage, url, NSBitmapImageFileTypeJPEG, _true ) // save image as jpg
handleevents- Output:
RGB Color values at pixel position X,Y are NSCalibratedRGBColorSpace 0 0 0.960784 1
Go
Standard library
Go's standard library include image, color, and drawing packages and the source for them is easy to read.
There is also a Go Blog article on the image package
The image.NRGBA type supports everything this task requires (the 'A' is for alpha channel, each are 8 bits, if 16 bits each of RGBA is desired there is also the image.NRGBA64 type). The 'N' of NRGBA stands for Non-alpha-premultiplied, color values can trivially be converted to/from alpha-premultiplied RGBA values via a color.Model.
Here's how to use the standard packages to do what this task requires:
package main
import (
"bytes"
"fmt"
"image"
"image/color"
"image/draw"
"image/png"
)
func main() {
// A rectangle from 0,0 to 300,240.
r := image.Rect(0, 0, 300, 240)
// Create an image
im := image.NewNRGBA(r)
// set some color variables for convience
var (
red = color.RGBA{0xff, 0x00, 0x00, 0xff}
blue = color.RGBA{0x00, 0x00, 0xff, 0xff}
)
// Fill with a uniform color
draw.Draw(im, r, &image.Uniform{red}, image.ZP, draw.Src)
// Set individual pixels
im.Set(10, 20, blue)
im.Set(20, 30, color.Black)
im.Set(30, 40, color.RGBA{0x10, 0x20, 0x30, 0xff})
// Get the values of specific pixels as color.Color types.
// The color will be in the color.Model of the image (in this
// case color.NRGBA) but color models can convert their values
// to other models.
c1 := im.At(0, 0)
c2 := im.At(10, 20)
// or directly as RGB components (scaled values)
redc, greenc, bluec, _ := c1.RGBA()
redc, greenc, bluec, _ = im.At(30, 40).RGBA()
// Images can be read and writen in various formats
var buf bytes.Buffer
err := png.Encode(&buf, im)
if err != nil {
fmt.Println(err)
}
fmt.Println("Image size:", im.Bounds().Dx(), "×", im.Bounds().Dy())
fmt.Println(buf.Len(), "bytes when encoded as PNG.")
fmt.Printf("Pixel at %7v is %v\n", image.Pt(0, 0), c1)
fmt.Printf("Pixel at %7v is %#v\n", image.Pt(10, 20), c2) // %#v shows type details
fmt.Printf("Pixel at %7v has R=%d, G=%d, B=%d\n",
image.Pt(30, 40), redc, greenc, bluec)
}
- Output:
Image size: 300 × 240
786 bytes when encoded as PNG.
Pixel at (0,0) is {255 0 0 255}
Pixel at (10,20) is color.NRGBA{R:0x0, G:0x0, B:0xff, A:0xff}
Pixel at (30,40) has R=4112, G=8224, B=12336
DIY
Not a complete working program. Presented here are just types and functions requested by the task.
// Raster package used with a number of RC tasks.
//
// For each task, documentation in package main source will list this
// file and others that are necessary to build a raster package with
// sufficient functionality for the task. To build a working program,
// build a raster package from the files listed, install the package,
// and then compile and link the package main that completes the task.
//
// Alternatively, files in the raster package can be combined as desired
// to build a package that meets the needs of multiple tasks.
package raster
// Rgb is a 24 bit color value represented with a 32 bit int
// in the conventional way. This is expected to be convenient
// for the programmer in many cases.
type Rgb int32
// Pixel has r, g, and b as separate fields. This is used as
// the in-memory representation of a bitmap.
type Pixel struct {
R, G, B byte
}
// Pixel returns a new Pixel from a Rgb value
func (c Rgb) Pixel() Pixel {
return Pixel{R: byte(c >> 16), G: byte(c >> 8), B: byte(c)}
}
// Rgb returns a single Rgb value computed from rgb fields of a Pixel
// of a Pixel.
func (p Pixel) Rgb() Rgb {
return Rgb(p.R)<<16 | Rgb(p.G)<<8 | Rgb(p.B)
}
// Bitmap is the in-memory representation, or image storage type of a bitmap.
// Zero value for type is a valid zero-size bitmap.
// The only exported field is Comments. Remaining fields have interdepencies
// that are managed by package code and so should not be directly accessed
// from outside the package.
type Bitmap struct {
Comments []string
rows, cols int
px []Pixel // all pixels as a single slice, row major order
pxRow [][]Pixel // rows of pixels as slices of px
}
const creator = "# Creator: Rosetta Code http://rosettacode.org/"
// New is a Bitmap "constructor." Parameters x and y are extents.
// That is, the new bitmap will have x columns and y rows.
func NewBitmap(x, y int) (b *Bitmap) {
b = &Bitmap{
Comments: []string{creator},
rows: y, // named fields here to prevent possible mix-ups.
cols: x,
px: make([]Pixel, x*y),
pxRow: make([][]Pixel, y),
}
// Note rows of pixels are not allocated separately.
// Rather the whole bitmap is allocted in one chunk as px.
// This simplifies allocation and maintains locality.
x0, x1 := 0, x
for i := range b.pxRow {
b.pxRow[i] = b.px[x0:x1] // slice operation. does no allocation.
x0, x1 = x1, x1+x
}
return b
}
// Extent returns bitmap dimensions.
func (b *Bitmap) Extent() (cols, rows int) {
return b.cols, b.rows
}
// Fill entire bitmap with solid color.
func (b *Bitmap) Fill(p Pixel) {
for i := range b.px {
b.px[i] = p
}
}
func (b *Bitmap) FillRgb(c Rgb) {
b.Fill(c.Pixel())
}
// Set a single pixel color value.
// Clips to bitmap boundaries.
// Returns true if pixel was set, false if clipped.
func (b *Bitmap) SetPx(x, y int, p Pixel) bool {
defer func() { recover() }()
b.pxRow[y][x] = p
return true
}
func (b *Bitmap) SetPxRgb(x, y int, c Rgb) bool {
return b.SetPx(x, y, c.Pixel())
}
// Note: Clipping to bitmap boundaries is needed for program correctness
// but is otherwise not required by the task. It is implemented with the
// combination of pxRow and the deferred recover. SetPx, GetPx return the
// clipping result as a way for higher level graphics functions to track
// plotting and clipping status. As this is not required by tasks though,
// it is generally not implemented.
// Get a single pixel color value.
// Returns pixel and ok=true if coordinates are within bitmap boundaries.
// Returns ok=false if coordinates are outside bitmap boundaries.
func (b *Bitmap) GetPx(x, y int) (p Pixel, ok bool) {
defer func() { recover() }()
return b.pxRow[y][x], true
}
func (b *Bitmap) GetPxRgb(x, y int) (Rgb, bool) {
p, ok := b.GetPx(x, y)
if !ok {
return 0, false
}
return p.Rgb(), true
}
Haskell
We implement the Image type as an STArray so that we can use it in an imperative fashion in the ST monad.
module Bitmap(module Bitmap) where
import Control.Monad
import Control.Monad.ST
import Data.Array.ST
newtype Pixel = Pixel (Int, Int) deriving Eq
instance Ord Pixel where
compare (Pixel (x1, y1)) (Pixel (x2, y2)) =
case compare y1 y2 of
EQ -> compare x1 x2
v -> v
instance Ix Pixel where
{- This instance differs from the one for (Int, Int) in that
the ordering of indices is
(0,0), (1,0), (2,0), (0,1), (1,1), (2,1)
instead of
(0,0), (0,1), (1,0), (1,1), (2,0), (2,1). -}
range (Pixel (xa, ya), Pixel (xz, yz)) =
[Pixel (x, y) | y <- [ya .. yz], x <- [xa .. xz]]
index (Pixel (xa, ya), Pixel (xz, _)) (Pixel (xi, yi)) =
(yi - ya)*(xz - xa + 1) + (xi - xa)
inRange (Pixel (xa, ya), Pixel (xz, yz)) (Pixel (xi, yi)) =
not $ xi < xa || xi > xz || yi < ya || yi > yz
rangeSize (Pixel (xa, ya), Pixel (xz, yz)) =
(xz - xa + 1) * (yz - ya + 1)
instance Show Pixel where
show (Pixel p) = show p
class Ord c => Color c where
luminance :: c -> Int
-- The Int should be in the range [0 .. 255].
black, white :: c
toNetpbm :: [c] -> String
fromNetpbm :: [Int] -> [c]
netpbmMagicNumber, netpbmMaxval :: c -> String
{- The argument to these two functions is ignored; the
parameter is only for typechecking. -}
newtype Color c => Image s c = Image (STArray s Pixel c)
image :: Color c => Int -> Int -> c -> ST s (Image s c)
{- Creates a new image with the given width and height, filled
with the given color. -}
image w h = liftM Image .
newArray (Pixel (0, 0), Pixel (w - 1, h - 1))
listImage :: Color c => Int -> Int -> [c] -> ST s (Image s c)
{- Creates a new image with the given width and height, with
each pixel set to the corresponding element of the given list. -}
listImage w h = liftM Image .
newListArray (Pixel (0, 0), Pixel (w - 1, h - 1))
dimensions :: Color c => Image s c -> ST s (Int, Int)
dimensions (Image i) = do
(_, Pixel (x, y)) <- getBounds i
return (x + 1, y + 1)
getPix :: Color c => Image s c -> Pixel -> ST s c
getPix (Image i) = readArray i
getPixels :: Color c => Image s c -> ST s [c]
getPixels (Image i) = getElems i
setPix :: Color c => Image s c -> Pixel -> c -> ST s ()
setPix (Image i) = writeArray i
fill :: Color c => Image s c -> c -> ST s ()
fill (Image i) c = getBounds i >>= mapM_ f . range
where f p = writeArray i p c
mapImage :: (Color c, Color c') =>
(c -> c') -> Image s c -> ST s (Image s c')
mapImage f (Image i) = liftM Image $ mapArray f i
This module provides an instance of Color.
module Bitmap.RGB(module Bitmap.RGB) where
import Bitmap
import Control.Monad.ST
newtype RGB = RGB (Int, Int, Int) deriving (Eq, Ord)
instance Color RGB where
luminance (RGB (r, g, b)) = round x
where x = 0.2126*r' + 0.7152*g' + 0.0722*b'
(r', g', b') = (toEnum r, toEnum g, toEnum b)
black = RGB (0, 0, 0)
white = RGB (255, 255, 255)
toNetpbm = concatMap f
where f (RGB (r, g, b)) = [toEnum r, toEnum g, toEnum b]
fromNetpbm [] = []
fromNetpbm (r : g : b : rest) = RGB (r, g, b) : fromNetpbm rest
netpbmMagicNumber _ = "P6"
netpbmMaxval _ = "255"
toRGBImage :: Color c => Image s c -> ST s (Image s RGB)
toRGBImage = mapImage $ f . luminance
where f x = RGB (x, x, x)
Icon and Unicon
The language has a built-in window data type with associated graphics primitives. A bitmap is just a window that isn't visible on-screen at the moment.
J
A number of addon packages are available for J that work with common image formats (including PPM), but here we will show a basic bitmap storage type as per the task description.
The structure is a 3-dimensional array of numbers. The shape of the array is height by width by 3. Each 1-dimensional cell of size 3 contains R, G and B numbers, in that order. Indexing is zero based. (We could instead have encoded RGB in a single integer...)
No parameter validity checks are currently implemented.
In J, allocating an uninitialized image would not normally be separated from creating
the colored image, so makeRGB allows the specification of color during allocation. As a monad, makeRGB creates a black image with the specified height and width. It can also take a left argument (dyadic form) specifying the color(s) of the image. fillRGB requires a left argument specifying the color(s), but takes a bitmap (RGB) structure as the right argument.
Solution:
makeRGB=: 0&$: : (($,)~ ,&3)
fillRGB=: makeRGB }:@$
setPixels=: (1&{::@[)`(<"1@(0&{::@[))`]}
getPixels=: <"1@[ { ]
Examples:
myimg=: makeRGB 5 8 NB. create a bitmap with height 5 and width 8 (black)
myimg=: 255 makeRGB 5 8 NB. create a white bitmap with height 5 and width 8
myimg=: 127 makeRGB 5 8 NB. create a gray bitmap with height 5 and width 8
myimg=: 0 255 0 makeRGB 5 8 NB. create a green bitmap with height 5 and width 8
myimg=: 0 0 255 fillRGB myimg NB. fill myimg with blue
colors=: 0 255 {~ #: i.8 NB. black,blue,green,cyan,red,magenta,yellow,white
myimg=: colors fillRGB myimg NB. fill myimg with vertical stripes of colors
2 4 getPixels myimg NB. get the pixel color from point (2, 4)
255 0 0
myimg=: (2 4 ; 255 255 255) setPixels myimg NB. set pixel at point (2, 4) to white
2 4 getPixels myimg NB. get the pixel color from point (2, 4)
255 255 255
}:$ myimg NB. get height and width of the image
5 8
getPixels and setPixels are generalized to set and get lists/arrays of pixels.
pixellist=: ,"0/~ i. 10 NB. row and column indices for 10 by 10 block of pixels
NB. create 10 by 10 block of magenta pixels in the middle of a 300 by 300 green image
myimg=: ((145 + pixellist) ; 255 0 255) setPixels 0 255 0 makeRGB 300 300
NB. get pixel color for 10x10 block offset from magenta block
subimg=: (140 + pixellist) getPixels myimg
To display the image in a window at any point for verification:
require 'viewmat'
viewRGB=: [: viewrgb 256&#.
viewRGB myimg
Note that height comes before width here. This is inconsistent with marketing of display resolutions, but matches J's treatment of dimensions.
Java
Solution
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
public class BasicBitmapStorage {
private final BufferedImage image;
public BasicBitmapStorage(int width, int height) {
image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
}
public void fill(Color c) {
Graphics g = image.getGraphics();
g.setColor(c);
g.fillRect(0, 0, image.getWidth(), image.getHeight());
}
public void setPixel(int x, int y, Color c) {
image.setRGB(x, y, c.getRGB());
}
public Color getPixel(int x, int y) {
return new Color(image.getRGB(x, y));
}
public Image getImage() {
return image;
}
}
Test Program
import static org.junit.Assert.assertEquals;
import java.awt.Color;
import org.junit.Test;
public class BasicBitmapStorageTest {
@Test
public void testHappy() {
int width = 640;
int height = 480;
BasicBitmapStorage bbs = new BasicBitmapStorage(width, height);
bbs.fill(Color.CYAN);
bbs.setPixel(width / 2, height / 2, Color.BLACK);
Color c1 = bbs.getPixel(width / 2, height / 2);
Color c2 = bbs.getPixel(20, 20);
assertEquals(Color.BLACK, c1);
assertEquals(Color.CYAN, c2);
}
}
JavaScript
JavaScript can interact with a drawing context using the HTML5 Canvas API.
// Set up the canvas
var canvas = document.createElement("canvas"),
ctx = canvas.getContext("2d"),
width = 400, height = 400;
ctx.canvas.width = width;
ctx.canvas.height = height;
// Optionaly add it to the current page
document.body.appendChild(canvas);
// Draw an image
var img = document.createElement("img");
img.onload = function(){
// Draw the element into the top-left of the canvas
ctx.drawImage(img, 0, 0);
};
img.src = "//placehold.it/400x400";
// Fill the canvas with a solid blue color
ctx.fillStyle = "blue";
ctx.fillRect(0, 0, width, height);
// Place a black pixel in the middle
// Note that a pixel is a 1 by 1 rectangle
// This is the fastest method as of 2012 benchmarks
ctx.fillStyle = "black";
ctx.fillRect(width / 2, height / 2, 1, 1);
Julia
Using packages (Images.jl, Colors.jl):
using Images, Colors
Base.hex(p::RGB{T}) where T = join(hex(c(p), 2) for c in (red, green, blue))
function showhex(m::Matrix{RGB{T}}, pad::Integer=4) where T
for r in 1:size(m, 1)
println(" " ^ pad, join(hex.(m[r, :]), " "))
end
end
w, h = 5, 7
cback = RGB(1, 0, 1)
cfore = RGB(0, 1, 0)
img = Array{RGB{N0f8}}(h, w);
println("Uninitialized image:")
showhex(img)
fill!(img, cback)
println("\nImage filled with background color:")
showhex(img)
img[2, 3] = cfore
println("\nImage with a pixel set for foreground color:")
showhex(img)
- Output:
Uninitialized image:
10DFF8 7F0000 F84A00 0030DA 007F00
4A007F B0DDF8 7F0000 F84A00 00D0DB
0000F0 4A007F D0D9F8 7F0000 F84A00
DFF84A 000050 4A007F 50DAF8 7F0000
007F00 D9F84A 000010 4A007F 30DCF8
0050E0 007F00 DAF84A 000050 4A007F
F84A00 00B0D9 007F00 DBF84A 000050
Image filled with background color:
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
Image with a pixel set for foreground color:
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF 00FF00 FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
FF00FF FF00FF FF00FF FF00FF FF00FF
KonsolScript
function main() {
Var:Number shape;
Image:New(50, 50, shape)
Draw:RectFill(0, 0, 50, 50, 0xFF0000, shape) //one to fill an image with a plain RED color
Draw:Pixel(30, 30, 0x0000FF, shape) //set a given pixel at (30,30) with a BLUE color
while (B1 == false) {
Image:Blit(10, 10, shape, screen)
Screen:Render()
}
}Kotlin
// version 1.1.4-3
import java.awt.Color
import java.awt.Graphics
import java.awt.image.BufferedImage
class BasicBitmapStorage(width: Int, height: Int) {
val image = BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR)
fun fill(c: Color) {
val g = image.graphics
g.color = c
g.fillRect(0, 0, image.width, image.height)
}
fun setPixel(x: Int, y: Int, c: Color) = image.setRGB(x, y, c.getRGB())
fun getPixel(x: Int, y: Int) = Color(image.getRGB(x, y))
}
fun main(args: Array<String>) {
val width = 640
val height = 480
val bbs = BasicBitmapStorage(width, height)
with (bbs) {
fill(Color.cyan)
setPixel(width / 2, height / 2, Color.black)
val c1 = getPixel(width / 2, height / 2)
val c2 = getPixel(20, 20)
print("The color of the pixel at (${width / 2}, ${height / 2}) is ")
println(if (c1 == Color.black) "black" else "unknown")
print("The color of the pixel at (120, 120) is ")
println(if (c2 == Color.cyan) "cyan" else "unknown")
}
}
- Output:
The color of the pixel at (320, 240) is black The color of the pixel at (120, 120) is cyan
Lingo
-- Creates a new image object of size 640x480 pixel and 32-bit color depth
img = image(640, 480, 32)
-- Fills image with plain red
img.fill(img.rect, rgb(255,0,0))
-- Gets the color value of the pixel at point (320, 240)
col = img.getPixel(320, 240)
-- Changes the color of the pixel at point (320, 240) to black
img.setPixel(320, 240, rgb(0,0,0))LiveCode
LiveCode has built in support for importing and exporting PBM, JPEG, GIF, BMP or PNG graphics formats
-- create an image container box at the center of the current stack window with default properties
create image "test"
-- programtically choose the paint bucket tool
choose bucket tool
-- LiveCode engine has built-in color keywords:
set the brushColor to "dark green"
-- programtically mouse click at the center of image container box to fill
click at the loc of image "test"
-- get the RGBA values of the first pixel in the image box
put byteToNum(byte 1 of the imageData of image "test") into tRed
put byteToNum(byte 2 of the imageData of image "test") into tGreen
put byteToNum(byte 3 of the imageData of image "test") into tBlue
put byteToNum(byte 4 of the imageData of image "test") into tAlpha
-- log message the info in the message box
put "First Pixel Color is Red:"& tRed &" Green:"& tGreen &" Blue:"& tBlue &" Transparency:"& tAlpha
-- just for fun replace the contents with RosettaCode logo
wait 2 seconds
set the filename of image "test" to "http://rosettacode.org/mw/title.png"
-- the next line is copy of the Write a PPM task:
export image "test" to file "~/Test.PPM" as paint -- paint format is one of PBM, PGM, or PPMLua
Original
function Allocate_Bitmap( width, height )
local bitmap = {}
for i = 1, width do
bitmap[i] = {}
for j = 1, height do
bitmap[i][j] = {}
end
end
return bitmap
end
function Fill_Bitmap( bitmap, color )
for i = 1, #bitmap do
for j = 1, #bitmap[1] do
bitmap[i][j] = color
end
end
end
function Get_Pixel( bitmap, x, y )
return bitmap[x][y]
end
This can be used like:
bitmap = Allocate_Bitmap( 100, 50 )
Fill_Bitmap( bitmap, { 15, 200, 80 } )
pixel = Get_Pixel( bitmap, 20, 25 )
print( pixel[1], pixel[2], pixel[3] )
Alternate
A more object-oriented and extensible approach for easier re-use elsewhere.
local Bitmap = {
new = function(self, width, height)
local instance = setmetatable({ width=width, height=height }, self)
instance:alloc()
return instance
end,
alloc = function(self)
self.pixels = {}
for y = 1, self.height do
self.pixels[y] = {}
for x = 1, self.width do
self.pixels[y][x] = 0x00000000
end
end
end,
clear = function(self, c)
for y = 1, self.height do
for x = 1, self.width do
self.pixels[y][x] = c or 0x00000000
end
end
end,
get = function(self, x, y)
x, y = math.floor(x+1), math.floor(y+1) -- given 0-based indices, use 1-based indices
if ((x>=1) and (x<=self.width) and (y>=1) and (y<=self.height)) then
return self.pixels[y][x]
else
return nil
end
end,
set = function(self, x, y, c)
x, y = math.floor(x+1), math.floor(y+1) -- given 0-based indices, use 1-based indices
if ((x>=1) and (x<=self.width) and (y>=1) and (y<=self.height)) then
self.pixels[y][x] = c or 0x00000000
end
end,
}
Bitmap.__index = Bitmap
setmetatable(Bitmap, { __call = function (t, ...) return t:new(...) end })
Usage:
local bitmap = Bitmap(32,32)
-- default pixel representation is 32-bit packed ARGB on [0,255]
bitmap:clear(0xFFFF0000) -- fill with red
bitmap:set(1, 1, 0xFF00FF00) -- one green pixel
bitmap:set(2, 2, 0xFF0000FF) -- one blue pixel
print(string.format("pixel at 0,0 = %x", bitmap:get(0,0)))
print(string.format("pixel at 1,1 = %x", bitmap:get(1,1)))
print(string.format("pixel at 2,2 = %x", bitmap:get(2,2)))
-- but note that pixel representation is agnostic..
-- (it's just a wrapper around a 2d-array of any valid type)
-- want to switch to RGB-tuple on [0,1]??
bitmap:clear({1,0,0}) -- fill with red
bitmap:set(1, 1, {0,1,0}) -- one green pixel
bitmap:set(2, 2, {0,0,1}) -- one blue pixel
print(string.format("pixel at 0,0 = %s", table.concat(bitmap:get(0,0),", ")))
print(string.format("pixel at 1,1 = %s", table.concat(bitmap:get(1,1),", ")))
print(string.format("pixel at 2,2 = %s", table.concat(bitmap:get(2,2),", ")))
-- or strings??
bitmap:clear("red") -- fill with red
bitmap:set(1, 1, "green") -- one green pixel
bitmap:set(2, 2, "blue") -- one blue pixel
print(string.format("pixel at 0,0 = %s", bitmap:get(0,0)))
print(string.format("pixel at 1,1 = %s", bitmap:get(1,1)))
print(string.format("pixel at 2,2 = %s", bitmap:get(2,2)))
Caveat: Just be aware that as currently written the storage of complex types are referenced rather than copied. So, for example, using the clear() method with a table representing an RGB-tuple, will store the same identical reference throughout the bitmap - so direct modification of any one pixel's internal components would affect all other pixels as well. You should override the clear() method as appropriate to better support your desired pixel representation if this is not the behavior you desire.
- Output:
pixel at 0,0 = ffff0000 pixel at 1,1 = ff00ff00 pixel at 2,2 = ff0000ff pixel at 0,0 = 1, 0, 0 pixel at 1,1 = 0, 1, 0 pixel at 2,2 = 0, 0, 1 pixel at 0,0 = red pixel at 1,1 = green pixel at 2,2 = blue
M2000 Interpreter
The easy way is to make a function to return an object with all functions on it, for specific image. We have to make the image in a way to render it to screen. The render statement get data in a string using a header of 12 characters (24 bytes). Raster lines are in down-top order. So last raster line is the top one. Also RGB is BGR in this data structure. Raster lines has to be aligned proper, so we may have add some bytes.
There are four functions (lambda functions) in the returned group, each of them has closures, an one of that closure is a pointer to a buffer object. We use this object to set and get pixels.
First two functions are for set and get pixel. Third return image as a string. Forth function copy an image as string to buffer, if they have the same width and height (else we get error)
P3 ppm
\ Bitmap width in pixels, height in pixels
\ Return a group object with some lambda as members: SetPixel, GetPixel, Image$
\ copyimage
\ using Copy x, y Use Image$ we can display image$ to x, y as twips
\ we can use x*twipsx, y*twipsy for x,y as pixels
Function Bitmap (x as long, y as long) {
if x<1 or y<1 then Error "Wrong dimensions"
structure rgb {
red as byte
green as byte
blue as byte
}
m=len(rgb)*x mod 4
if m>0 then m=4-m ' add some bytes to raster line
m+=len(rgb) *x
Structure rasterline {
{
pad as byte*m
}
\\ union pad+hline
hline as rgb*x
}
Structure Raster {
magic as integer*4
w as integer*4
h as integer*4
lines as rasterline*y
}
Buffer Clear Image1 as Raster
\\ 24 chars as header to be used from bitmap render build in functions
Return Image1, 0!magic:="cDIB", 0!w:=Hex$(x,2), 0!h:=Hex$(y, 2)
\\ fill white (all 255)
\\ Str$(string) convert to ascii, so we get all characters from words width to byte width
Return Image1, 0!lines:=Str$(String$(chrcode$(255), Len(rasterline)*y))
Buffer Clear Pad as Byte*4
SetPixel=Lambda Image1, Pad,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x, y, c) ->{
where=alines+3*x+blines*y
if c>0 then c=color(c)
c-!
Return Pad, 0:=c as long
Return Image1, 0!where:=Eval(Pad, 2) as byte, 0!where+1:=Eval(Pad, 1) as byte, 0!where+2:=Eval(Pad, 0) as byte
}
GetPixel=Lambda Image1,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x,y) ->{
where=alines+3*x+blines*y
=color(Eval(image1, where+2 as byte), Eval(image1, where+1 as byte), Eval(image1, where as byte))
}
StrDib$=Lambda$ Image1, Raster -> {
=Eval$(Image1, 0, Len(Raster))
}
CopyImage=Lambda Image1 (image$) -> {
if left$(image$,12)=Eval$(Image1, 0, 24 ) Then {
Return Image1, 0:=Image$
} Else Error "Can't Copy Image"
}
Group Bitmap {
SetPixel=SetPixel
GetPixel=GetPixel
Image$=StrDib$
Copy=CopyImage
}
=Bitmap
}
A=Bitmap(100,100)
Call A.SetPixel(50,50, color(128,0,255))
Print A.GetPixel(50,50)=color(128,0,255)
\\ display image to screen at 100, 50 pixel
copy 100*twipsx,50*twipsy use A.Image$()
A1=Bitmap(100,100)
Call A1.copy(A.Image$())
copy 500*twipsx,50*twipsy use A1.Image$()P6 ppm
Need Version 9.4, Rev >=19
Module P6 {
Function Bitmap {
def x as long, y as long, Import as boolean
If match("NN") then {
Read x, y
} else.if Match("N") Then {
\\ is a file?
Read f as long
buffer whitespace as byte
if not Eof(f) then {
get #f, whitespace :P6$=eval$(whitespace)
get #f, whitespace : P6$+=eval$(whitespace)
def boolean getW=true, getH=true, getV=true
def long v
\\ str$("P6") has 2 bytes. "P6" has 4 bytes
If p6$=str$("P6") Then {
do {
get #f, whitespace
if Eval$(whitespace)=str$("#") then {
do {get #f, whitespace} until eval(whitespace)=10
} else {
select case eval(whitespace)
case 32, 9, 13, 10
{ if getW and x<>0 then {
getW=false
} else.if getH and y<>0 then {
getH=false
} else.if getV and v<>0 then {
getV=false
}
}
case 48 to 57
{if getW then {
x*=10
x+=eval(whitespace, 0)-48
} else.if getH then {
y*=10
y+=eval(whitespace, 0)-48
} else.if getV then {
v*=10
v+=eval(whitespace, 0)-48
}
}
End Select
}
iF eof(f) then Error "Not a ppm file"
} until getV=false
} else Error "Not a P6 ppm"
Import=True
}
} else Error "No proper arguments"
if x<1 or y<1 then Error "Wrong dimensions"
structure rgb {
red as byte
green as byte
blue as byte
}
m=len(rgb)*x mod 4
if m>0 then m=4-m ' add some bytes to raster line
m+=len(rgb) *x
Structure rasterline {
{
pad as byte*m
}
hline as rgb*x
}
Structure Raster {
magic as integer*4
w as integer*4
h as integer*4
{
linesB as byte*len(rasterline)*y
}
lines as rasterline*y
}
Buffer Clear Image1 as Raster
Return Image1, 0!magic:="cDIB", 0!w:=Hex$(x,2), 0!h:=Hex$(y, 2)
if not Import then Return Image1, 0!lines:=Str$(String$(chrcode$(255), Len(rasterline)*y))
Buffer Clear Pad as Byte*4
SetPixel=Lambda Image1, Pad,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x, y, c) ->{
where=alines+3*x+blines*y
if c>0 then c=color(c)
c-!
Return Pad, 0:=c as long
Return Image1, 0!where:=Eval(Pad, 2) as byte, 0!where+1:=Eval(Pad, 1) as byte, 0!where+2:=Eval(Pad, 0) as byte
}
GetPixel=Lambda Image1,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x,y) ->{
where=alines+3*x+blines*y
=color(Eval(image1, where+2 as byte), Eval(image1, where+1 as byte), Eval(image1, where as byte))
}
StrDib$=Lambda$ Image1, Raster -> {
=Eval$(Image1, 0, Len(Raster))
}
CopyImage=Lambda Image1 (image$) -> {
if left$(image$,12)=Eval$(Image1, 0, 24 ) Then {
Return Image1, 0:=Image$
} Else Error "Can't Copy Image"
}
Export2File=Lambda Image1, x, y (f) -> {
Print #f, "P6";chr$(10);"# Created using M2000 Interpreter";chr$(10);
Print #f, x;" ";y;" 255";chr$(10);
x2=x-1 : where=0
Buffer pad as byte*3
For y1= 0 to y-1 {
For x1=0 to x2 {
Return pad, 0:=eval$(image1, 0!linesB!where, 3)
Push Eval(pad, 2) : Return pad, 2:=Eval(pad, 0), 0:=Number
Put #f, pad : where+=3
}
m=where mod 4 : if m<>0 then where+=4-m
}
}
if Import then {
x0=x-1 : where=0
Buffer Pad1 as byte*3
For y1=y-1 to 0 {
For x1=0 to x0 {Get #f, Pad1 : Push Eval(pad1, 2) : Return pad1, 2:=Eval(pad1, 0), 0:=Number
Return Image1, 0!linesB!where:=Eval$(Pad1) : where+=3}
m=where mod 4 : if m<>0 then where+=4-m}
}
Group Bitmap {
SetPixel=SetPixel
GetPixel=GetPixel
Image$=StrDib$
Copy=CopyImage
ToFile=Export2File
}
=Bitmap
}
A=Bitmap(150,100)
For i=0 to 98 {
Call A.SetPixel(i, i, 0)
Call A.SetPixel(99, i, 0)
}
Call A.SetPixel(i,i,0)
Copy 200*twipsx, 100*twipsy use A.Image$()
Profiler
Open "a.ppm" for output as #F
Call A.tofile(f)
Close #f
Print Filelen("a.ppm")
Print Timecount/1000;"sec"
Profiler
Image A.Image$() Export "a.jpg", 100 ' per cent quality
Print Filelen("a.jpg")
Image A.Image$() Export "a1.jpg", 10 ' per cent quality
Print Filelen("a1.jpg")
Image A.Image$() Export "a.bmp"
Print Filelen("a.bmp") ' no compression
Print Timecount/1000;"sec"
Move 5000,5000 ' twips
Image "a.jpg"
Move 5000,8000
Image "a1.jpg"
Move 8000, 5000
Image "a.bmp"
}
P6Export using M2000 code for ppm is slower than using internal jpg and bmp encoders. Jpg encoder has a 100% quality, and because this image is black and white we get the best compression. Time 0.304sec is for three exports, two jpg and one bmp.
- Output:
45049
47.3661341sec
1018
691
45254
0.3040944sec
Maple
allocateImg := proc(width, height)
return Array(1..width, 1..height, 1..3);
end proc:
fillColor := proc(img, rgb::list)
local i;
for i from 1 to 3 do
img[..,..,i] := map(x->rgb[i], img[..,..,i]):
end do:
end proc:
setColor := proc(x, y, img, rgb::list)
local i:
for i from 1 to 3 do
img[x,y,i] := rgb[i]:
end do:
end proc:
getColor := proc(x,y,img)
local rgb,i:
rgb := Array(1..3):
for i from 1 to 3 do
rgb(i) := img[x,y,i]:
end do:
return rgb:
end proc:- Use:
a := allocateImg(200,200); fillColor(a,[255,223,0]); setColor(150,150, a, [0,0,0]); getColor(150,150,a); #Output the image ImageTools:-Embed(ImageTools:-Create(a))
Mathematica / Wolfram Language
In Mathematica 7/8:
img = Image[ConstantArray[{1, 0, 0}, {1000, 1000}]];
img = ReplacePart[img, {1, 1, 1} -> {0, 0, 1}];
ImageValue[img, {1, 1}]
In Mathematica 9:
img = Image[ConstantArray[{1, 0, 0}, {1000, 1000}]];
img = ReplacePixelValue[img, {1, 1} -> {0, 0, 1}];
ImageValue[img, {1, 1}]
MATLAB
Save this in a file named Bitmap.mat in a folder named @Bitmap in your MATLAB root directory.
%Bitmap class
%
%Implements a class to manage bitmap images without the need for the
%various conversion and display functions
%
%Available functions:
%
%fill(obj,color)
%setPixel(obj,pixel,color)
%getPixel(obj,pixel,[optional: color channel])
%display(obj)
%disp(obj)
%plot(obj)
%image(obj)
%save(obj)
%open(obj)
classdef Bitmap
%% Public Properties
properties
%Channel arrays
red;
green;
blue;
end
%% Public Methods
methods
%Creates image and defaults it to black
function obj = Bitmap(width,height)
obj.red = zeros(height,width,'uint8');
obj.green = zeros(height,width,'uint8');
obj.blue = zeros(height,width,'uint8');
end % End Bitmap Constructor
%Fill the image with a specified color
%color = [red green blue] max for each is 255
function fill(obj,color)
obj.red(:,:) = color(1);
obj.green(:,:) = color(2);
obj.blue(:,:) = color(3);
assignin('caller',inputname(1),obj); %saves the changes to the object
end
%Set a pixel to a specified color
%pixel = [x y]
%color = [red green blue]
function setPixel(obj,pixel,color)
obj.red(pixel(2),pixel(1)) = color(1);
obj.green(pixel(2),pixel(1)) = color(2);
obj.blue(pixel(2),pixel(1)) = color(3);
assignin('caller',inputname(1),obj); %saves the changes to the object
end
%Get pixel color
%pixel = [x y]
%varargin can be:
% no input for all channels
% 'r' or 'red' for red channel
% 'g' or 'green' for green channel
% 'b' or 'blue' for blue channel
function color = getPixel(obj,pixel,varargin)
if( ~isempty(varargin) )
switch (varargin{1})
case {'r','red'}
color = obj.red(pixel(2),pixel(1));
case {'g','green'}
color = obj.red(pixel(2),pixel(1));
case {'b','blue'}
color = obj.red(pixel(2),pixel(1));
end
else
color = [obj.red(pixel(2),pixel(1)) obj.green(pixel(2),pixel(1)) obj.blue(pixel(2),pixel(1))];
end
end
%Display the image
%varargin can be:
% no input for all channels
% 'r' or 'red' for red channel
% 'g' or 'green' for green channel
% 'b' or 'blue' for blue channel
function display(obj,varargin)
if( ~isempty(varargin) )
switch (varargin{1})
case {'r','red'}
image(obj.red)
case {'g','green'}
image(obj.green)
case {'b','blue'}
image(obj.blue)
end
colormap bone;
else
bitmap = cat(3,obj.red,obj.green,obj.blue);
image(bitmap);
end
end
%Overload several commonly used display functions
function disp(obj,varargin)
display(obj,varargin{:});
end
function plot(obj,varargin)
display(obj,varargin{:});
end
function image(obj,varargin)
display(obj,varargin{:});
end
%Saves the image
function save(obj)
%Open file dialogue
[fileName,pathName,success] = uiputfile({'*.bmp','Bitmap Image (*.bmp)'},'Save Bitmap As');
if( not(success == 0) )
imwrite(cat(3,obj.red,obj.green,obj.blue),[pathName fileName],'bmp'); %Write image file to disk
disp('Save Complete');
end
end
%Opens an image and overwrites what is currently stored
function success = open(obj)
%Open file dialogue
[fileName,pathName,success] = uigetfile({'*.bmp','Bitmap Image (*.bmp)'},'Open Bitmap ');
if( not(success == 0) )
channels = imread([pathName fileName], 'bmp'); %returns color indexed data
%Store each channel
obj.red = channels(:,:,1);
obj.green = channels(:,:,2);
obj.blue = channels(:,:,3);
assignin('caller',inputname(1),obj); %saves the changes to the object
success = true;
return
else
success = false;
return
end
end
end %methods
end %classdef
Sample Usage:
>> img = Bitmap(20,30);
>> img.fill([30 30 150]);
>> img.setPixel([10 15],[20 130 66]);
>> disp(img)
>> img.getPixel([10 15])
ans =
20 130 66
>> img.getPixel([10 15],'red')
ans =
20
>> img.save()
Save Complete
MAXScript
MAXScript provides a built-in Bitmap class.
local myBitmap = bitmap 512 512Filling the image with a single colour can be accomplished at creation time by setting the color property.
local myBitmap = bitmap 512 512 color:(color 128 128 128)Use setPixels to set the colour of a pixel. This function takes an array of colours and is optimised to set the colours of a whole row of pixels.
setPixels myBitmap [256, 256] #((color 255 255 255))Use getPixels to retrieve the colour of a pixel. As with setPixels, this function is optimised to retrieve one row at a time as an array of colour values.
local myPixel = getPixels myBitmap [256, 256] 1MiniScript
This GUI implementation is for use with Mini Micro.
// MiniMicro version of MiniScript has all the
// necessary methods built-in to complete this task.
width = 256
height = 256
colr = color.aqua
// Create the image with specified width/heigh. With
// no parameters, it defaults width/height to 64 and
// color to black
img = Image.create(width, height, colr)
// Create a diagonal line of multiple colors. Uses
// Cartesian coordinates so (0, 0) is lower left corner.
for i in range(0, 255)
img.setPixel i, i, color.rgb(i, i, i)
end for
// Get pixel color as RGBA hex values
print "Color at pixel (100, 100): " + img.pixel(100, 100)
print "Color at pixel (0, 0): " + img.pixel(0, 0)
print "Color at pixel (127, 127): " + img.pixel(127, 127)
print "Color at pixel (255, 255): " + img.pixel(255, 255)
// Display the image, resizing it to 127 x 127
gfx.drawImage img, 0, 0, 127, 127
// Save the file - accepted file extensions:
// tga, jpg, jpeg, and png (retains transparency)
// Optional third parameter is JPG compression quality.
file.saveImage "/usr/test.png", img
Modula-3
Since this code is for use with other tasks, it uses an interface as well as the implementation module.
INTERFACE Bitmap;
TYPE UByte = BITS 8 FOR [0 .. 16_FF];
Pixel = RECORD R, G, B: UByte; END;
Point = RECORD x, y: UByte; END;
T = REF ARRAY OF ARRAY OF Pixel;
CONST
Black = Pixel{0, 0, 0};
White = Pixel{255, 255, 255};
Red = Pixel{255, 0, 0};
Green = Pixel{0, 255, 0};
Blue = Pixel{0, 0, 255};
Yellow = Pixel{255, 255, 0};
EXCEPTION BadImage;
BadColor;
PROCEDURE NewImage(height, width: UByte): T RAISES {BadImage};
PROCEDURE Fill(VAR pic: T; color: Pixel);
PROCEDURE GetPixel(VAR pic: T; point: Point): Pixel RAISES {BadColor};
PROCEDURE SetPixel(VAR pic: T; point: Point; color: Pixel);
END Bitmap.
MODULE Bitmap;
PROCEDURE NewImage(height, width: UByte): T RAISES {BadImage} =
(* To make things easier, limit image size to also
be UByte (0 to 255), and to have equal dimensions. *)
BEGIN
IF height # width THEN
RAISE BadImage;
END;
RETURN NEW(T, height, width);
END NewImage;
PROCEDURE Fill(VAR pic: T; color: Pixel) =
BEGIN
FOR i := FIRST(pic^) TO LAST(pic^) DO
FOR j := FIRST(pic[0]) TO LAST(pic[0]) DO
pic[i,j] := color;
END;
END;
END Fill;
PROCEDURE GetPixel(VAR pic: T; point: Point): Pixel RAISES {BadColor} =
VAR pixel := pic[point.x, point.y];
BEGIN
IF pixel = White THEN
RETURN White;
ELSIF pixel = Black THEN
RETURN Black;
ELSIF pixel = Red THEN
RETURN Red;
ELSIF pixel = Green THEN
RETURN Green;
ELSIF pixel = Blue THEN
RETURN Blue;
ELSIF pixel = Yellow THEN
RETURN Yellow;
ELSE
RAISE BadColor;
END;
END GetPixel;
PROCEDURE SetPixel(VAR pic: T; point: Point; color: Pixel) =
BEGIN
pic[point.x, point.y] := color;
END SetPixel;
BEGIN
END Bitmap.
Nim
type
Luminance* = uint8
Index* = int
Color* = tuple
r, g, b: Luminance
Image* = ref object
w*, h*: Index
pixels*: seq[Color]
Point* = tuple
x, y: Index
proc color*(r, g, b: SomeInteger): Color =
## Build a color value from R, G and B values.
result.r = r.uint8
result.g = g.uint8
result.b = b.uint8
const
Black* = color( 0, 0, 0)
White* = color(255, 255, 255)
proc newImage*(width, height: int): Image =
## Create an image with given width and height.
new(result)
result.w = width
result.h = height
result.pixels.setLen(width * height)
iterator indices*(img: Image): Point =
## Yield the pixels coordinates as tuples.
for y in 0 ..< img.h:
for x in 0 ..< img.w:
yield (x, y)
proc `[]`*(img: Image; x, y: int): Color =
## Get a pixel RGB value.
img.pixels[y * img.w + x]
proc `[]=`*(img: Image; x, y: int; c: Color) =
## Set a pixel RGB value to given color.
img.pixels[y * img.w + x] = c
proc fill*(img: Image; color: Color) =
## Fill the image with a color.
for x, y in img.indices:
img[x, y] = color
proc print*(img: Image) =
## Output an ASCII representation of the image.
for x, y in img.indices:
if x mod img.w == 0:
stdout.write '\n'
stdout.write if img[x, y] == White: '.' else: 'H'
stdout.write '\n'
when isMainModule:
var img = newImage(100, 20)
img.fill color(255, 255, 255)
img[1, 2] = color(255, 0, 0)
img[3, 4] = img[1, 2]
img.print
OCaml
let new_img ~width ~height =
let all_channels =
let kind = Bigarray.int8_unsigned
and layout = Bigarray.c_layout
in
Bigarray.Array3.create kind layout 3 width height
in
let r_channel = Bigarray.Array3.slice_left_2 all_channels 0
and g_channel = Bigarray.Array3.slice_left_2 all_channels 1
and b_channel = Bigarray.Array3.slice_left_2 all_channels 2
in
(all_channels,
r_channel,
g_channel,
b_channel)
and here is the type of the raster image this function returns:
type raster = (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array3.t * (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array2.t * (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array2.t * (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array2.t
What is particular with this allocation and its associated type is that there is not only one buffer for each RGB channel, but also an additionnal one that handles all the three channels, and what is important here is that it is not additionnal memory, the memory is shared, so there are 2 ways to access the raster buffer: through the separated RGB channels, or through the joint channel (all_channels).
This solution have a lot of advantages across a more naive one: this type is compatible to memory-map a file (a ppm file for instance, where the data is not compressed), the buffer can be shared/exchanged with C (for OpenGL textures for instance), etc.
A more naive form would be this one:
let new_img ~width ~height =
let r_channel, g_channel, b_channel =
let kind = Bigarray.int8_unsigned
and layout = Bigarray.c_layout
in
(Bigarray.Array2.create kind layout width height,
Bigarray.Array2.create kind layout width height,
Bigarray.Array2.create kind layout width height)
in
(r_channel,
g_channel,
b_channel)
Here are the functions to fill with a color and to set one given pixel:
let fill_img ~img:(_, r_channel, g_channel, b_channel) ~color:(r,g,b) =
Bigarray.Array2.fill r_channel r;
Bigarray.Array2.fill g_channel g;
Bigarray.Array2.fill b_channel b;
;;
let put_pixel_unsafe (_, r_channel, g_channel, b_channel) (r,g,b) =
(fun x y ->
r_channel.{x,y} <- r;
g_channel.{x,y} <- g;
b_channel.{x,y} <- b;
)
let get_pixel_unsafe (_, r_channel, g_channel, b_channel) =
(fun x y ->
(r_channel.{x,y},
g_channel.{x,y},
b_channel.{x,y})
)
we can overload these functions to make some bound checks:
let put_pixel img color x y =
let _, r_channel,_,_ = img in
let width = Bigarray.Array2.dim1 r_channel
and height = Bigarray.Array2.dim2 r_channel in
if (x < 0) || (x >= width) then invalid_arg "x out of bounds";
if (y < 0) || (y >= height) then invalid_arg "y out of bounds";
let r, g, b = color in
if (r < 0) || (r > 255) then invalid_arg "red out of bounds";
if (g < 0) || (g > 255) then invalid_arg "green out of bounds";
if (b < 0) || (b > 255) then invalid_arg "blue out of bounds";
put_pixel_unsafe img color x y;
;;
let get_pixel ~img ~pt:(x, y) =
let _, r_channel,_,_ = img in
let width = Bigarray.Array2.dim1 r_channel
and height = Bigarray.Array2.dim2 r_channel in
if (x < 0) || (x >= width) then invalid_arg "x out of bounds";
if (y < 0) || (y >= height) then invalid_arg "y out of bounds";
get_pixel_unsafe img x y;
;;
and a function to get the dimensions:
let get_dims ~img:(_, r_channel, _, _) =
let width = Bigarray.Array2.dim1 r_channel
and height = Bigarray.Array2.dim2 r_channel in
(width, height)
Octave
In Octave, images are matrix. A grayscale W×H image is stored as a W×H matrix, and RGB W×H image is stored as a W×H×3 image. Possible levels depend on the class of the storage: if it is double, the intensity is a floating point double number between 0 and 1; if it is uint8, the intensity is from 0 to 255; if it is uint16, the intensity is between 0 and 65535.
im = zeros(W, H, 3, "uint8"); % create an RGB image of width W and height H
% and intensity from 0 to 255; black (all zeros)
im(:,:,1) = 255; % set R to 255
im(:,:,2) = 100; % set G to 100
im(:,:,3) = 155; % set B to 155
im(floor(W/2), floor(H/2), :) = 0; % pixel in the center made black
disp(im(floor(W/3), floor(H/3), :)) % display intensities of the pixel
% at W/3, H/3
p = im(40,40,:); % or just store it in the vector p, so that
% p(1) is R, p(2) G and p(3) is B
We can hide this in helper functions like:
function im = create_rgb_image(w, h)
im = zeros(w, h, 3, "uint8");
endfunction
function set_background(im, colorvector)
im(:,:,1) = colorvector(1);
im(:,:,2) = colorvector(2);
im(:,:,3) = colorvector(3);
endfunction
function set_pixel(im, coord, colorvector)
im(coord(1), coord(2), 1) = colorvector(1);
im(coord(1), coord(2), 2) = colorvector(2);
im(coord(1), coord(2), 3) = colorvector(3);
endfunction
function [r, g, b] = get_pixel(im, coord)
r = im(coord(1), coord(2), 1)
g = im(coord(1), coord(2), 2)
b = im(coord(1), coord(2), 3)
endfunction
The only thing to note is that indexing start from 1.
%example
im = create_rgb_image(200,200);
for x = 1:128
im = set_pixel(im, [x, x], [200, 50, 220]);
endfor
% it seems like saveimage wants double class on [0,1]
saveimage("image.ppm", double(im)./256, "ppm");
OxygenBasic
'GENERIC BITMAP
type pixel byte r,g,b
'===========
class BitMap
'===========
% sp sizeof(pixel)
sys wx,wy,px,py
string buf
sys pb
method Constructor(sys x=640,y=480) { wx=x : wy=y : buf=nuls x*y*sp : pb=strptr buf}
method Destructor() {buf="" : wx=0 : wy=0 : pb=0}
method GetPixel(sys x,y,pixel*p) {copy @p,pb+(y*wx+x)*sp,sp}
method SetPixel(sys x,y,pixel*p) {copy pb+(y*wx+x)*sp,@p,sp}
'
method Fill(pixel*p)
sys i, e=wx*wy*sp+pb-1
for i=pb to e step sp {copy i,@p,sp}
end method
end class
pixel p,q
new BitMap m(400,400) 'width, height in pixels
p<=100,120,140 'red,green,blue
m.fill p
m.getPixel 200,100,q
print "" q.r "," q.g "," q.b 'result 100,120,140
q<=10,20,40
m.setPixel 200,100,q
m.getPixel 200,100,p
print "" p.r "," p.g "," p.b 'result 10,20,40
del mOz
We first create a 2D array data type as a functor in a file "Array2D.oz":
functor
export
New
Get
Set
Transform
define
fun {New Width Height Init}
C = {Array.new 1 Height unit}
in
for Row in 1..Height do
C.Row := {Array.new 1 Width Init}
end
array2d(width:Width
height:Height
contents:C)
end
fun {Get array2d(contents:C ...) X Y}
C.Y.X
end
proc {Set array2d(contents:C ...) X Y Val}
C.Y.X := Val
end
proc {Transform array2d(contents:C width:W height:H ...) Fun}
for Y in 1..H do
for X in 1..W do
C.Y.X := {Fun C.Y.X}
end
end
end
%% omitted: Clone, Map, Fold, ForAll
endBased on this, we create a functor "Bitmap.oz":
%% For real task prefer QTk's images:
%% http://www.mozart-oz.org/home/doc/mozart-stdlib/wp/qtk/html/node38.html
functor
import
Array2D
export
New
Fill
GetPixel
SetPixel
define
Black = color(0x00 0x00 0x00)
fun {New Width Height}
bitmap( {Array2D.new Width Height Black} )
end
proc {Fill bitmap(Arr) Color}
{Array2D.transform Arr fun {$ _} Color end}
end
fun {GetPixel bitmap(Arr) X Y}
{Array2D.get Arr X Y}
end
proc {SetPixel bitmap(Arr) X Y Color}
{Array2D.set Arr X Y Color}
end
%% Omitted: MaxValue, ForAllPixels, Transform
endSome functions that are used in other tasks were omitted. See here for the complete module definitions: Basic bitmap storage/Oz
Pascal
Interface
uses crt, { GetDir }
graph; { function GetPixel }
type { integer numbers }
{ from unit bitmaps XPERT software production Tamer Fakhoury }
_bit = $00000000..$00000001; {number 1 bit without sign = (0..1) }
_byte = $00000000..$000000FF; {number 1 byte without sign = (0..255)}
_word = $00000000..$0000FFFF; {number 2 bytes without sign = (0..65 535)}
_dWord = $00000000..$7FFFFFFF; {number 4 bytes without sign = (0..4 294 967 296)}
_longInt = $80000000..$7FFFFFFF; {number 4 bytes with sign
= (-2 147 483 648..2 147 483 648}
TbmpFileHeader =
record
ID: _word; { Must be 'BM' =19778=$424D for windows }
FileSize: _dWord; { Size of this file in bytes }
Reserved: _dWord; { ??? }
bmpDataOffset: _dword; { = 54 = $36 from begining of file to begining of bmp data }
end;
TbmpInfoHeader =
record
InfoHeaderSize: _dword; { Size of Info header
= 28h = 40 (decimal)
for windows }
Width,
Height: _longInt; { Width and Height of image in pixels }
Planes, { number of planes of bitmap }
BitsPerPixel: _word; { Bits can be 1, 4, 8, 24 or 32 }
Compression,
bmpDataSize: _dword; { in bytes rounded to the next 4 byte boundary }
XPixPerMeter, { horizontal resolution in pixels }
YPixPerMeter: _longInt; { vertical }
NumbColorsUsed,
NumbImportantColors: _dword; {= NumbColorUsed}
end; { TbmpHeader = Record ... }
T32Color =
record { 4 byte = 32 bit }
Blue: byte;
Green: byte;
Red: byte;
Alfa: byte
end;
var directory,
bmpFileName: string;
bmpFile: file; { untyped file }
bmpFileHeader: TbmpFileHeader;
bmpInfoHeader: TbmpInfoHeader;
color32: T32Color;
RowSizeInBytes: integer;
BytesPerPixel: integer;
const defaultBmpFileName = 'test';
DefaultDirectory = 'c:\bp\';
DefaultExtension = '.bmp';
bmpFileHeaderSize = 14;
{ compression specyfication }
bi_RGB = 0; { compression }
bi_RLE8 = 1;
bi_RLE4 = 2;
bi_BITFIELDS = 3;
bmp_OK = 0;
bmp_NotBMP = 1;
bmp_OpenError = 2;
bmp_ReadError = 3;
Procedure CreateBmpFile32(directory: string; FileName: string;
iWidth, iHeight: _LongInt);
{************************************************}
Implementation {-----------------------------}
{************************************************}
Procedure CreateBmpFile32(directory: string; FileName: string;
iWidth, iHeight: _LongInt);
var
x, y: integer;
begin
if directory = '' then
GetDir(0, directory);
if FileName = '' then
FileName: = DefaultBmpFileName;
{ create a new file on a disk in a given directory with given name }
Assign(bmpFile, directory + FileName + DefaultExtension);
ReWrite(bmpFile, 1);
{ fill the headers }
with bmpInfoHeader, bmpFileHeader do
begin
ID := 19778;
InfoheaderSize := 40;
width := iWidth;
height := iHeight;
BitsPerPixel := 32;
BytesPerPixel := BitsPerPixel div 8;
reserved := 0;
bmpDataOffset := InfoHeaderSize + bmpFileHeaderSize;
planes := 1;
compression := bi_RGB;
XPixPerMeter := 0;
YPixPerMeter := 0;
NumbColorsUsed := 0;
NumbImportantColors := 0;
RowSizeInBytes := (Width * BytesPerPixel); { only for >=8 bits per pixel }
bmpDataSize := height * RowSizeinBytes;
FileSize := InfoHeaderSize + bmpFileHeaderSize + bmpDataSize;
{ copy headers to disk file }
BlockWrite(bmpFile, bmpFileHeader, bmpFileHeaderSize);
BlockWrite(bmpFile, bmpInfoHeader, infoHeaderSize);
{ fill the pixel data area }
for y := (height - 1) downto 0 do
begin
for x := 0 to (width - 1) do
begin { Pixel(x,y) }
color32.Blue := 255;
color32.Green := 0;
color32.Red := 0;
color32.Alfa := 0;
BlockWrite(bmpFile, color32, 4);
end; { for x ... }
end; { for y ... }
Close(bmpFile);
end; { with bmpInfoHeader, bmpFileHeader }
end; { procedure }
Perl
#! /usr/bin/perl
use strict;
use Image::Imlib2;
# create the "canvas"
my $img = Image::Imlib2->new(200,200);
# fill with a plain RGB(A) color
$img->set_color(255, 0, 0, 255);
$img->fill_rectangle(0,0, 200, 200);
# set a pixel to green (at 40,40)
$img->set_color(0, 255, 0, 255);
$img->draw_point(40,40);
# "get" pixel rgb(a)
my ($red, $green, $blue, $alpha) = $img->query_pixel(40,40);
undef $img;
# another way of creating a canvas with a bg colour (or from
# an existing "raw" data)
my $col = pack("CCCC", 255, 255, 0, 0); # a, r, g, b
my $img = Image::Imlib2->new_using_data(200, 200, $col x (200 * 200));
exit 0;
Phix
Copy of Euphoria
with javascript_semantics -- Some colour constants: constant black = #000000, -- blue = #0000FF, -- green = #00FF00, -- red = #FF0000, white = #FFFFFF -- Create new image filled with some colour function new_image(integer width, integer height, integer fill_colour=black) return repeat(repeat(fill_colour,height),width) end function -- Usage example: sequence image = new_image(800,600) -- Set pixel color: image[400][300] = white -- Get pixel color integer colour = image[400][300] -- Now colour is #FFFFFF
PHP
class Bitmap {
public $data;
public $w;
public $h;
public function __construct($w = 16, $h = 16){
$white = array_fill(0, $w, array(255,255,255));
$this->data = array_fill(0, $h, $white);
$this->w = $w;
$this->h = $h;
}
//Fills a rectangle, or the whole image with black by default
public function fill($x = 0, $y = 0, $w = null, $h = null, $color = array(0,0,0)){
if (is_null($w)) $w = $this->w;
if (is_null($h)) $h = $this->h;
$w += $x;
$h += $y;
for ($i = $y; $i < $h; $i++){
for ($j = $x; $j < $w; $j++){
$this->setPixel($j, $i, $color);
}
}
}
public function setPixel($x, $y, $color = array(0,0,0)){
if ($x >= $this->w) return false;
if ($x < 0) return false;
if ($y >= $this->h) return false;
if ($y < 0) return false;
$this->data[$y][$x] = $color;
}
public function getPixel($x, $y){
return $this->data[$y][$x];
}
}
$b = new Bitmap(16,16);
$b->fill();
$b->fill(2, 2, 18, 18, array(240,240,240));
$b->setPixel(0, 15, array(255,0,0));
print_r($b->getPixel(3,3)); //(240,240,240)
PicoLisp
For time critical applications this would be done with inline-C in PicoLisp, but especially for small bitmaps the following makes sense.
# Create an empty image of 120 x 90 pixels
(setq *Ppm (make (do 90 (link (need 120)))))
# Fill an image with a given color
(de ppmFill (Ppm R G B)
(for Y Ppm
(map
'((X) (set X (list R G B)))
Y ) ) )
# Set pixel with a color
(de ppmSetPixel (Ppm X Y R G B)
(set (nth Ppm Y X) (list R G B)) )
# Get the color of a pixel
(de ppmGetPixel (Ppm X Y)
(get Ppm Y X) )PL/I
/* Declaration for an image, suitable for BMP files. */
declare image(0:500, 0:500) bit (24) aligned;
image = '000000000000000011111111'b;
/* Sets the entire image to red. */
image(10,40) = '111111110000000000000000'b;
/* Sets one pixel to blue. */
declare color bit (24) aligned;
color = image(20,50); /* Obtain the color of a pixel */
/* To allocate an image of size (x,y) */
allocate_image: procedure (image, x, y);
declare image (*, *) controlled bit (24) aligned;
declare (x, y) fixed binary (31);
allocate image (0:x, 0:y);
end allocate_image;
/* To use the above procedure, it's necessary to define */
/* the image in the calling program thus, for BMP images: */
declare image(*,*) controlled bit (24) aligned;POV-Ray
//cmd: +w300 +h300 +am2 +a0.01
#version 3.7;
#global_settings {assumed_gamma 1}
#default{ finish{ ambient 0.1 diffuse 0.9 }}
background {rgb 0}
#macro mapInit(DimX, DimY)
#local Map = array[DimX][DimY];
mapFillSolid(Map, rgb<0,0,0>)
Map
#end
#macro mapFillSolid(Map, Colour)
mapFillRect(Map,<0,0>,<dimension_size(Map,1),dimension_size(Map,2)>, Colour)
#end
#macro mapFillRect(Map, RectLowerLeft, RectUpperRight, Colour)
#for (X, RectLowerLeft.x, RectUpperRight.x - 1)
#for (Y, RectLowerLeft.y, RectUpperRight.y - 1)
#local Map[X][Y] = Colour;
#end
#end
#end
#macro mapSetPixel(Map, Pixel, Colour)
#local Map[Pixel.x][Pixel.y] = Colour;
#end
#macro mapGetPixel(Map, Pixel)
Map[Pixel.x][Pixel.y]
#end
#macro mapObject(Map)
// to visualize the map, each pixel is rendered as a sphere
#for (X,0,dimension_size(Map,1)-1)
#for (Y,0,dimension_size(Map,2)-1)
sphere{
<X, Y, 0>, 0.5
pigment{colour Map[X][Y]}
}
#end
#end
#end
//== Scene
#declare DimX = 100;
#declare DimY = 100;
#declare ImgMap = mapInit(DimX, DimY);
mapFillSolid(ImgMap, rgb<1, 0, 0>)
mapSetPixel(ImgMap, <25,25>, rgb<1,1,1>)
mapFillRect(ImgMap, <50,50>, <75,75>, rgb<0,0,1>)
#debug concat("Colour at: <", vstr(2,<25,25>,", ",0,0),"> is: <", vstr(3, mapGetPixel(ImgMap, <25,25>),", ",0,0),">\n")
mapObject(ImgMap)
camera{
location <DimX/2, DimY/2, -110>
look_at <DimX/2, DimY/2, 0>
right x*image_width/image_height
}
light_source{
<DimX/2, DimY/2, -3000>
rgb 1
}
- Output:
Processing
PGraphics bitmap = createGraphics(100,100); // Create the bitmap
bitmap.beginDraw();
bitmap.background(255, 0, 0); // Fill bitmap with red rgb color
bitmap.endDraw();
image(bitmap, 0, 0); // Place bitmap on screen.
color b = color(0, 0, 255); // Define a blue rgb color
set(50, 50, b); // Set blue colored pixel in the middle of the screen
color c = get(50, 50); // Get the color of same pixel
if(b == c) print("Color changed correctly"); // Verify
Prolog
:- module(bitmap, [
new_bitmap/3,
fill_bitmap/3,
get_pixel0/3,
set_pixel0/4 ]).
:- use_module(library(lists)).
%-----------------------------------------------------------------------------%
% Convenience Predicates
replicate(Term,Times,L):-
length(L,Times),
maplist(=(Term),L).
replace0(N,OL,E,NL):-
nth0(N,OL,_,TL),
nth0(N,NL,E,TL).
%-----------------------------------------------------------------------------%
% Bitmap Utilities
%
% The Bitmap structure is a list with pixels kept in row major order:
% [dimensions-[X,Y],pixels-[[n11,n12...],[n21,n22...]]]
% In this code what exactly an RGB value is doesn't matter however
% in other bitmap tasks it is assumed to be a list [R,G,B] where
% each is an int between 0 and 255, in code:
rgb_pixel(RGB):-
length(RGB,3),
maplist(integer,RGB),
maplist(between(0,255),RGB).
%new_bitmap(Bitmap,Dimensions,RGB)
new_bitmap([[X,Y],Pixels],[X,Y],RGB) :-
replicate(RGB,X,Row),
replicate(Row,Y,Pixels).
%fill_bitmap(New_Bitmap,Bitmap,RGB)
fill_bitmap(New_Bitmap,[[X,Y],_],RGB) :-
new_bitmap(New_Bitmap,[X,Y],RGB).
%here get and set use 0 based indexing
%get_pixel0(Bitmap,Coordinates,RGB)
get_pixel0([[_DimX,_DimY],Pixels],[X,Y],RGB) :-
nth0(Y,Pixels,Row),
nth0(X,Row,RGB).
%set_pixel0(New Bitmap, Bitmap, Coordinates, RGB)
set_pixel0([[DimX,DimY],New_Pixels],[[DimX,DimY],Pixels],[X,Y],RGB) :-
nth0(Y,Pixels,Row),
replace0(X,Row,RGB,New_Row),
replace0(Y,Pixels,New_Row,New_Pixels).
PureBasic
w=800 : h=600
CreateImage(1,w,h)
;1 is internal id of image
StartDrawing(ImageOutput(1))
; fill with color red
Box(0,0,w,h,$ff)
; or using another (but slower) way in green
FillArea(0,0,-1,$ff00)
; a green Dot
Plot(10,10,$ff0000)
; check if we set it right (should be 255)
Debug Blue(Point(10,10))
Python
See Basic bitmap storage/Python
QBasic
SUB establecePixel (x AS INTEGER, y AS INTEGER, c AS INTEGER)
PSET (x, y), cyan
END SUB
SUB rellenar (c AS INTEGER)
SHARED w, h
LINE (0, 0)-(w / 3, h / 3), red, BF
END SUB
SCREEN 13
w = 320: h = 200
CONST cyan = 3, red = 4
rellenar (12)
CALL establecePixel(10, 10, cyan)
LOCATE 12
PRINT "pixel 10,10 is "; POINT(10, 10)
PRINT "pixel 20,20 is "; POINT(20, 10)
R
R can write to most bitmap image formats by default (mostly for the purpose of saving graphs), however there is no built-in way of manipulating images. The pixmap package reads, writes and manipulates portable bitmap file types: PBM, PGM, PPM. See also, the image function, and the rimage and ReadImage packages, which use libjpeg to read JPEG and PNG files.
# See the class definitions and constructors with, e.g.
getClass("pixmapIndexed", package=pixmap)
pixmapIndexed
# Image with all one colour
plot(p1 <- pixmapIndexed(matrix(0, nrow=3, ncol=4), col="red"))
# Image with one pixel specified
cols <- rep("blue", 12); cols[7] <- "red"
plot(p2 <- pixmapIndexed(matrix(1:12, nrow=3, ncol=4), col=cols))
# Retrieve colour of a pixel
getcol <- function(pm, i, j)
{
pmcol <- pm@col
dim(pmcol) <- dim(pm@index)
pmcol[i,j]
}
getcol(p2, 3, 4) #red
Racket
#lang racket
;; The racket/draw libraries provide imperative drawing functions.
;; http://docs.racket-lang.org/draw/index.html
(require racket/draw)
;; To create an image with width and height, use the make-bitmap
;; function.
;; For example, let's make a small image here:
(define bm (make-bitmap 640 480))
;; We use a drawing context handle, a "dc", to operate on the bitmap.
(define dc (send bm make-dc))
;; We can fill the bitmap with a color by using a combination of
;; setting the background, and clearing.
(send dc set-background (make-object color% 0 0 0)) ;; Color it black.
(send dc clear)
;; Let's set a few pixels to a greenish color with set-pixel:
(define aquamarine (send the-color-database find-color "aquamarine"))
(for ([i 480])
(send dc set-pixel i i aquamarine))
;; We can get at the color of a bitmap pixel by using the get-pixel
;; method. However, it may be faster to use get-argb-pixels if we
;; need a block of the pixels. Let's use get-argb-pixels and look
;; at a row starting at (0, 42)
(define buffer (make-bytes (* 480 4))) ;; alpha, red, green, blue
(send dc get-argb-pixels 0 42 480 1 buffer)
;; We can inspect the buffer
(bytes-ref buffer 0) ;; and see that the first pixel's alpha is 255,
(bytes-ref buffer 1) ;; and the red, green, and blue components are 0.
(bytes-ref buffer 2)
(bytes-ref buffer 3)
;; If we are using DrRacket, we can just print the bm as a toplevel expression
;; to view the final image:
bm
Raku
(formerly Perl 6)
class Pixel { has UInt ($.R, $.G, $.B) }
class Bitmap {
has UInt ($.width, $.height);
has Pixel @!data;
method fill(Pixel $p) {
@!data = $p.clone xx ($!width*$!height)
}
method pixel(
$i where ^$!width,
$j where ^$!height
--> Pixel
) is rw { @!data[$i + $j * $!width] }
method set-pixel ($i, $j, Pixel $p) {
self.pixel($i, $j) = $p.clone;
}
method get-pixel ($i, $j) returns Pixel {
self.pixel($i, $j);
}
}
my Bitmap $b = Bitmap.new( width => 10, height => 10);
$b.fill( Pixel.new( R => 0, G => 0, B => 200) );
$b.set-pixel( 7, 5, Pixel.new( R => 100, G => 200, B => 0) );
say $b.perl;
Thanks to the rw trait on the pixel method, we don't actually need to define two separate methods, set-pixel and get-pixel, but that is an explicit requirement of the task. (Beware your presuppositions! In Raku, accessors only determine identity, not use. In particular, identity is considered orthogonal to lvalue/rvalue context.)
RapidQ
QCanvas is an empty image on which you can draw. QForm is the main window of the application. The commands to draw on the canvas are in the procedure PaintCanvas, which is executed each time the canvas need to be (re)painted.
DECLARE SUB PaintCanvas
CREATE form AS QForm
Width = 640
Height = 480
CREATE canvas AS QCanvas
Height = form.ClientHeight
Width = form.ClientWidth
OnPaint = PaintCanvas
END CREATE
END CREATE
SUB PaintCanvas
' Fill background
canvas.FillRect(0, 0, canvas.Width, canvas.Height, &H301000)
' Draw a pixel
canvas.Pset(300, 200, &H00ddff)
' Read pixel color
PRINT canvas.Pixel(300, 200)
END SUB
form.ShowModalREXX
version 1
The REXX language has no need to declare the size of (stemmed) arrays.
Indeed, there is no way to declare array sizes (or any variable, for that matter).
The image (raster) created was also written to a file (image.PPM) to show verification of the image.
/*REXX program demonstrates how to process/display */
/* a simple RGB raster graphics image.*/
red = 'ff 00 00'x /*a method to define a red value. */
blue = '00 00 ff'x /*' ' ' ' ' blue ' */
pixel='' /*define entire pixel. array to nulls.*/
outFN = 'image' /*the filename of the output image PPM */
sWidth = 500; sHeight= 500 /*the screen width and height in pixels*/
Call RGBfill red /*set the entire image to red. */
x=10; y=40 /*set pixel's coördinates. */
Call RGBset x,y,blue /*set a pixel (at 10,40) to blue. */
color = RGBget(x,y) /*get the color of a pixel. */
hexV = c2x(color) /*get hex value of pixel's color. */
binV = x2b(hexV) /* " binary " " " " */
bin3V = left(binV,8) substr(binV,9,8) right(binV,8)
hex3V = left(hexV,2) substr(hexV,3,2) right(hexV,2)
xy= '('||x','y')' /*create a handy-dandy literal for SAY.*/
Say xy ' pixel in binary: ' binV /*show the binary value of 20,50 */
Say xy ' pixel in binary: ' bin3V /*show again,but with spaces. */
Say /*show a blank between bin & hex. */
Say xy ' pixel in hex: ' hexV /*show again,but in hexadecimal. */
Say xy ' pixel in hex: ' hex3V /*show again,but with spaces. */
Call PPMwrite outFN,sWidth,sHeight /*create a PPM (output) file */
/* ?¦¦¦¦¦¦¦¦ not part of this task.*/
Say /*show a blank. */
Say 'The file ' outFN'.PPM was created.' /*inform user */
Exit /*stick a fork in it, we're all done. */
/*---------------------------------------------------------------------*/
RGBfill: pixel.=arg(1); Return /*fill image with a color.*/
RGBget: Parse arg px,py; Return pixel.px.py /*get a pixel's color. */
RGBset: Parse arg px,py,psep; pixel.px.py=psep; Return /*set a pixel */
/*---------------------------------------------------------------------*/
PPMwrite: Parse arg oFN,width,height
oFID= oFN'.PPM' /* fileID */
sep='9'x; /* separator */
maxcol=255 /* max color value. */
Call charout oFID,,1 /*set the position of the file's output*/
Call charout oFID,'P6'width||sep||height||sep||maxcol||sep /* header */
Do i=1 To width
Do j=1 To height;
Call charout oFID,pixel.i.j
End
End
Call charout oFID /* close the output file just to be safe */
Return
- output:
(10,40) pixel in binary: 000000000000000011111111 (10,40) pixel in binary: 00000000 00000000 11111111 (10,40) pixel in hex: 0000FF (10,40) pixel in hex: 00 00 FF The file image.PPM was created.
version 2
This program actually creates a BMP file
/* REXX ***************************************************************
* Draw a picture from pixels
* 16.06.2014 Walter Pachl
**********************************************************************/
oid='pic.bmp'; 'erase' oid
blue ='FF0000'x;
green='00FF00'x;
red ='0000FF'x;
white='ffffff'x;
black='000000'x;
w=600 /* width */
h=300 /* height */
w3=w*3
bfType ='BM'
bfSize ='46000000'x
bfReserved ='00000000'x
bfOffBits ='36000000'x
biSize ='28000000'x
biWidth =lend(w)
biHeight =lend(h)
biPlanes ='0100'x
biBitCount ='1800'x
biCompression ='00000000'x
biSizeImage ='10000000'x
biXPelsPerMeter='00000000'x
biYPelsPerMeter='00000000'x
biClrUsed ='00000000'x
biClrImportant ='00000000'x
s=bfType||,
bfSize||,
bfReserved||,
bfOffBits||,
biSize||,
biWidth||,
biHeight||,
biPlanes||,
biBitCount||,
biCompression||,
biSizeImage||,
biXPelsPerMeter||,
biYPelsPerMeter||,
biClrUsed||,
biClrImportant
pic=copies(red,w*h) /* fill the rectangle with color red */
Call rect 100,100,180,180,green /* draw a green rectangle */
Call rect 100,100,160,160,blue /* and a blue rectangle within that */
Call dot 120,120,white /* one pixel is hardly visible */
Do x=98 To 102 /* draw a square of 25 pixels */
Do y=98 To 102
Call dot x,y,white
End
End
Call charout oid,s||pic /* write the picture to file */
dmy=col(97,98)
dmy=col(98,98)
Exit
lend: Procedure
/**********************************************************************
* compute the representation of a number (little endian)
**********************************************************************/
Parse Arg n
res=reverse(d2c(n,4))
rev=reverse(res)
say 'lend:' arg(1) '->' c2x(res) '=>' c2d(rev)
Return res
rect: Procedure Expose pic w h w3
/**********************************************************************
* Fill a rectangle with center at x,y and width/height = wr/hr
**********************************************************************/
Parse Arg x,y,wr,hr,color
Say x y wr hr c2x(color)
i=w3*(y-1)+3*(x-1)+1 /* Pixel position of center */
ia=max(w3*(y-1)+1,i-3*(wr%2)) /* position of left border */
ib=min(i+3*wr%2,w3*y) /* position of right border */
lc=ib-ia /* length of horizontal line */
If lc>=0 Then Do
os=copies(color,lc%3) /* the horizontal line */
Do hi=-hr%2 to hr%2 /* loop from lower to upper border*/
i=trunc(ia+w3*hi) /* position of line's left border */
If i>1 Then Do
pic=overlay(os,pic,i) /* put the line into the picture */
j=i%w3
End
End
End
Return
dot: Procedure Expose pic w h w3
/**********************************************************************
* Put a dot at position x/y into the picture
**********************************************************************/
Parse Arg x,y,color
i=w3*(y-1)+3*(x-1)
pic=overlay(color,pic,i+1)
Return
col: Procedure Expose pic w h w3
/**********************************************************************
* get the color at position x/y
**********************************************************************/
Parse Arg x,y,color
i=w3*(y-1)+3*(x-1)
say 'color at pixel' x'/'y'='c2x(substr(pic,i+1,3))
Return c2x(substr(pic,i+1,3))
- Output:
lend: 600 -> 58020000 => 600 lend: 300 -> 2C010000 => 300 100 100 180 180 00FF00 100 100 160 160 FF0000 color at pixel 97/98=FF0000 color at pixel 98/98=FFFFFF and have a look at the file pic.bmp created by this program
Ruby
I haven't been able to find any kind of package for manipulating bitmap images, so let's roll one
class RGBColour
def initialize(red, green, blue)
unless red.between?(0,255) and green.between?(0,255) and blue.between?(0,255)
raise ArgumentError, "invalid RGB parameters: #{[red, green, blue].inspect}"
end
@red, @green, @blue = red, green, blue
end
attr_reader :red, :green, :blue
alias_method :r, :red
alias_method :g, :green
alias_method :b, :blue
RED = RGBColour.new(255,0,0)
GREEN = RGBColour.new(0,255,0)
BLUE = RGBColour.new(0,0,255)
BLACK = RGBColour.new(0,0,0)
WHITE = RGBColour.new(255,255,255)
end
class Pixmap
def initialize(width, height)
@width = width
@height = height
@data = fill(RGBColour::WHITE)
end
attr_reader :width, :height
def fill(colour)
@data = Array.new(@width) {Array.new(@height, colour)}
end
def validate_pixel(x,y)
unless x.between?(0, @width-1) and y.between?(0, @height-1)
raise ArgumentError, "requested pixel (#{x}, #{y}) is outside dimensions of this bitmap"
end
end
def [](x,y)
validate_pixel(x,y)
@data[x][y]
end
alias_method :get_pixel, :[]
def []=(x,y,colour)
validate_pixel(x,y)
@data[x][y] = colour
end
alias_method :set_pixel, :[]=
end
Rust
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct Rgb {
pub r: u8,
pub g: u8,
pub b: u8,
}
impl Rgb {
pub fn new(r: u8, g: u8, b: u8) -> Self {
Rgb { r, g, b }
}
pub const BLACK: Rgb = Rgb { r: 0, g: 0, b: 0 };
pub const RED: Rgb = Rgb { r: 255, g: 0, b: 0 };
pub const GREEN: Rgb = Rgb { r: 0, g: 255, b: 0 };
pub const BLUE: Rgb = Rgb { r: 0, g: 0, b: 255 };
}
#[derive(Clone, Debug)]
pub struct Image {
width: usize,
height: usize,
pixels: Vec<Rgb>,
}
impl Image {
pub fn new(width: usize, height: usize) -> Self {
Image {
width,
height,
pixels: vec![Rgb::BLACK; width * height],
}
}
pub fn width(&self) -> usize {
self.width
}
pub fn height(&self) -> usize {
self.height
}
pub fn fill(&mut self, color: Rgb) {
for pixel in &mut self.pixels {
*pixel = color;
}
}
pub fn get(&self, row: usize, col: usize) -> Option<&Rgb> {
if row >= self.width {
return None;
}
self.pixels.get(row * self.width + col)
}
pub fn get_mut(&mut self, row: usize, col: usize) -> Option<&mut Rgb> {
if row >= self.width {
return None;
}
self.pixels.get_mut(row * self.width + col)
}
}
fn main() {
let mut image = Image::new(16, 9);
assert_eq!(Some(&Rgb::BLACK), image.get(3, 4));
assert!(image.get(22, 3).is_none());
image.fill(Rgb::RED);
assert_eq!(Some(&Rgb::RED), image.get(3, 4));
if let Some(pixel) = image.get_mut(3, 4) {
*pixel = Rgb::GREEN;
}
assert_eq!(Some(&Rgb::GREEN), image.get(3, 4));
if let Some(pixel) = image.get_mut(3, 4) {
pixel.g -= 100;
pixel.b = 20;
}
assert_eq!(Some(&Rgb::new(0, 155, 20)), image.get(3, 4));
}
Scala
Java translation
import java.awt.image.BufferedImage
import java.awt.Color
class RgbBitmap(val width:Int, val height:Int) {
val image=new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR)
def fill(c:Color)={
val g=image.getGraphics()
g.setColor(c)
g.fillRect(0, 0, width, height)
}
def setPixel(x:Int, y:Int, c:Color)=image.setRGB(x, y, c.getRGB())
def getPixel(x:Int, y:Int)=new Color(image.getRGB(x, y))
}
Usage:
val img=new RgbBitmap(50, 50);
img.fill(Color.CYAN)
img.setPixel(5, 5, Color.BLUE)
assert(img.getPixel(1,1)==Color.CYAN)
assert(img.getPixel(5,5)==Color.BLUE)
assert(img.width==50)
assert(img.height==50)
Scala idiom
A more Scalesque version could be with the use of its idiom:
- Output:
Best experienced in your browser with Scastie (remote JVM).
import java.awt.image.BufferedImage
import java.awt.Color
object RgbBitmap extends App {
class RgbBitmap(val dim: (Int, Int)) {
def width = dim._1
def height = dim._2
private val image = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR)
def apply(x: Int, y: Int) = new Color(image.getRGB(x, y))
def update(x: Int, y: Int, c: Color) = image.setRGB(x, y, c.getRGB)
def fill(c: Color) = {
val g = image.getGraphics
g.setColor(c)
g.fillRect(0, 0, width, height)
}
}
object RgbBitmap {
def apply(width: Int, height: Int) = new RgbBitmap(width, height)
}
/** Even Javanese style testing is still possible.
*/
private val img0 = new RgbBitmap(50, 60) { // Wrappers to enable adhoc Javanese style
def getPixel(x: Int, y: Int) = this(x, y)
def setPixel(x: Int, y: Int, c: Color) = this(x, y) = c
}
img0.fill(Color.CYAN)
img0.setPixel(5, 6, Color.BLUE)
// Testing in Java style
assert(img0.getPixel(0, 1) == Color.CYAN)
assert(img0.getPixel(5, 6) == Color.BLUE)
assert(img0.width == 50)
assert(img0.height == 60)
println("Tests successfully completed with no errors found.")
}
Scheme
Works with: Scheme version RRS
Definitions of list procedures:
(define (make-list length object)
(if (= length 0)
(list)
(cons object (make-list (- length 1) object))))
(define (list-fill! list object)
(if (not (null? list))
(begin (set-car! list object) (list-fill! (cdr list) object))))
(define (list-set! list element object)
(if (= element 1)
(set-car! list object)
(list-set! (cdr list) (- element 1) object)))
(define (list-get list element)
(if (= element 1)
(car list)
(list-get (cdr list) (- element 1))))
Definitions of image procedures:
(define (make-image columns rows)
(if (= rows 0)
(list)
(cons (make-list columns (list)) (make-image columns (- rows 1)))))
(define (image-fill! image colour)
(if (not (null? image))
(begin (list-fill! (car image) colour) (image-fill! (cdr image) colour))))
(define (image-set! image column row colour)
(list-set! (list-get image row) column colour))
(define (image-get image column row)
(list-get (list-get image row) column))
Definitions of some colours:
(define *black* (list 0 0 0))
(define *white* (list 255 255 255))
(define *red* (list 255 0 0))
(define *green* (list 0 255 0))
(define *blue* (list 0 0 255))
This creates a small image with a black background and a single blue pixel:
(define image (make-image 3 2))
(image-fill! image *black*)
(image-set! image 2 1 *blue*)
(display image)
(newline)
- Output:
(((0 0 0) (0 0 255) (0 0 0)) ((0 0 0) (0 0 0) (0 0 0)))
Seed7
The types and functions requested are predefined in the libraries graph.s7i and draw.s7i:
- The type to handle an RGB raster graphics image is PRIMITIVE_WINDOW.
- The function to create an image is newPixmap.
- An imaged can be filled with a color with clear.
- A given pixel can be set with point.
- The color of a pixel can be retrieved with getPixelColor.
$ include "seed7_05.s7i";
include "draw.s7i";
const proc: main is func
local
var PRIMITIVE_WINDOW: myPixmap is PRIMITIVE_WINDOW.value;
var color: myColor is black;
begin
myPixmap := newPixmap(300, 200);
clear(myPixmap, light_green);
point(myPixmap, 20, 30, color(256, 512, 768));
myColor := getPixelColor(myPixmap, 20, 30);
writeln(myColor.redLight <& " " <& myColor.greenLight <& " " <& myColor.blueLight);
end func;SequenceL
RGB ::= (R: int(0), G: int(0), B: int(0));
newBitmap: int * int -> RGB(2);
newBitmap(width, height)[y, x] :=
(R: 0, G: 0, B: 0)
foreach y within 1 ... height,
x within 1 ... width;
fill: RGB(2) * RGB -> RGB(2);
fill(bitmap(2), color)[y, x] :=
color
foreach y within 1 ... size(bitmap),
x within 1 ... size(bitmap[y]);
setColorAt: RGB(2) * int * int * RGB -> RGB(2);
setColorAt(bitmap(2), x, y, color)[Y, X] :=
color when Y = y and X = x
else
bitmap[Y, X];
getColorAt: RGB(2) * int * int -> RGB;
getColorAt(bitmap(2), x, y) := bitmap[y, x];
lightGreen := (R: 51, G: 255, B: 51);
lightRed := (R: 255, G: 51, B: 51);
main(args(2)) :=
let
width := 1920;
height := 1200;
cleanImage := newBitmap(width, height);
filledGreen := fill(cleanImage, lightGreen);
redCenter := setColorAt(filledGreen, width / 2, height / 2, lightRed);
in
getColorAt(redCenter, width / 2, height / 2);- Output:
cmd:> main.exe (B:51,G:51,R:255)
Smalltalk
|img1 img2|
"a depth24 RGB image"
img1 := Image width:100 height:200 depth:24.
img1 fillRectangle:(0@0 corner:100@100) with:Color red.
img1 fillRectangle:(0@100 corner:100@100) with:(Color rgbValue: 16rFF00FF).
img1 colorAt:(10 @ 10) put:(Color green).
img1 saveOn:'sampleFile.png'.
img1 displayOn:Transcript window graphicsContext.
Transcript showCR:(img1 colorAt:(100 @ 10) ).
"a depth8 palette image"
img2 := Image width:100 height:200 depth:8.
img2 colorMap:{ Color black. Color red . Color green }.
img2 fillRectangle:(0@0 corner:100@100) with:Color red.
img2 fillRectangle:(0@100 corner:100@100) with: 16r02.
img2 colorAt:(10 @ 10) put:(Color green).
img2 saveOn:'sampleFile.gif'.
img2 displayOn:Transcript window graphicsContext.
Transcript showCR:(img2 colorAt:(100 @ 10) ).
Tcl
package require Tcl 8.5
package require Tk
namespace path ::tcl::mathfunc ;# for [max] function
proc newImage {width height} {
return [image create photo -width $width -height $height]
}
proc fill {image colour} {
$image put $colour -to 0 0 [$image cget -width] [$image cget -height]
}
proc setPixel {image colour point} {
lassign $point x y
$image put $colour -to [max 0 $x] [max 0 $y]
}
proc getPixel {image point} {
lassign $point x y
# [$img get] returns a list: {r g b}; this proc should return a colour value
format {#%02x%02x%02x} {*}[$image get $x $y]
}
# create the image and display it
set img [newImage 150 150]
label .l -image $img
pack .l
fill $img red
setPixel $img green {40 40}
set rbg [getPixel $img {40 40}]
TI-89 BASIC
TI-89 BASIC does not have user-defined data structures. The Rosetta Code tasks which use this image type have instead been implemented using the TI-89's graph screen.
UNIX Shell
typeset -T RGBColor_t=(
integer r g b
function to_s {
printf "%d %d %d" ${_.r} ${_.g} ${_.b}
}
function white { print "255 255 255"; }
function black { print "0 0 0"; }
function red { print "255 0 0"; }
function green { print "0 255 0"; }
function blue { print "0 0 255"; }
function yellow { print "255 255 0"; }
function magenta { print "255 0 255"; }
function cyan { print "0 255 255"; }
)
typeset -T Bitmap_t=(
integer height
integer width
typeset -a data
function fill {
typeset color=$1
if [[ -z ${color:+set} ]]; then
print -u2 "error: no fill color specified"
return 1
fi
integer x y
for ((y=0; y<_.height; y++)); do
for ((x=0; x<_.width; x++)); do
_.data[y][x]="$color"
done
done
}
function setpixel {
integer x=$1 y=$2
typeset color=$3
_.data[y][x]=$color
}
function getpixel {
integer x=$1 y=$2
print "${_.data[y][x]}"
}
function to_s {
typeset ppm=""
ppm+="P3"$'\n'
ppm+="${_.width} ${_.height}"$'\n'
ppm+="255"$'\n'
typeset sep
for ((y=0; y<_.height; y++)); do
sep=""
for ((x=0; x<_.width; x++)); do
ppm+="$sep${_.data[y][x]}"
sep=" "
done
ppm+=$'\n'
done
print -- "$ppm"
}
)
RGBColor_t color
Bitmap_t b=( width=3 height=2 )
b.fill "$(color.white)"
b.setpixel 0 0 "$(color.red)"
b.setpixel 1 0 "$(color.green)"
b.setpixel 2 0 "$(color.blue)"
b.setpixel 0 1 "$(color.yellow)"
b.setpixel 1 1 "$(color.white)"
b.setpixel 2 1 "$(color.black)"
echo "$(b.getpixel 0 0)"
b.to_s
- Output:
255 0 0 P3 3 2 255 255 0 0 0 255 0 0 0 255 255 255 0 255 255 255 0 0 0
Vedit macro language
An edit buffer is used to store pixel data. In order to allow unlimited image size, a temporary file (here pixel.data) can be assosicated to the buffer. You could directly open the image file you are creating (as in the task Dragon_curve, but here we first create just the plain pixel data so that the required image file format can be decided later.
#11 = 400 // Width of the image
#12 = 300 // Height of the image
// Create an empty RGB image and fill it with black color
//
File_Open("|(VEDIT_TEMP)\pixel.data", OVERWRITE+NOEVENT)
BOF
Del_Char(ALL)
#10 = Buf_Num
Repeat(#11 * #12) {
Ins_Char(0, COUNT, 3)
}
// Fill the image with dark blue color
//
#5 = 0 // Red
#6 = 0 // Green
#7 = 64 // Blue
Call("FILL_IMAGE")
// Draw one pixel in orange color
//
#1 = 100 // x
#2 = 50 // y
#5 = 255 #6 = 128 #7 = 0 // Orange color
Call("DRAW_PIXEL")
// Get the color of a pixel
//
#1 = 10
#2 = 3
Call("GET_COLOR")
Buf_Switch(#10) Buf_Quit(OK)
Return
/////////////////////////////////////////////////////////////////////
//
// Fill image with given color: #5 = Red, #6 = Green, #7 = Blue
//
:FILL_IMAGE:
BOF
Repeat (File_Size/3) {
IC(#5,OVERWRITE) IC(#6,OVERWRITE) IC(#7,OVERWRITE)
}
Return
/////////////////////////////////////////////////////////////////////
//
// Daw a pixel. #1 = x, #2 = y
//
:DRAW_PIXEL:
Goto_Pos((#1 + #2*#11)*3)
IC(#5,OVERWRITE) IC(#6,OVERWRITE) IC(#7,OVERWRITE)
Return
/////////////////////////////////////////////////////////////////////
//
// Get color of a pixel. #1 = x, #2 = y
// Return: #5 = Red, #6 = Green, #7 = Blue
//
:GET_COLOR:
Goto_Pos((#1 + #2*#11)*3)
#5 = Cur_Char
#6 = Cur_Char(1)
#7 = Cur_Char(2)
ReturnVisual Basic .NET
' The StructLayout attribute allows fields to overlap in memory.
<System.Runtime.InteropServices.StructLayout(LayoutKind.Explicit)> _
Public Structure Rgb
<FieldOffset(0)> _
Public Rgb As Integer
<FieldOffset(0)> _
Public B As Byte
<FieldOffset(1)> _
Public G As Byte
<FieldOffset(2)> _
Public R As Byte
Public Sub New(ByVal r As Byte, ByVal g As Byte, ByVal b As Byte)
Me.R = r
Me.G = g
Me.B = b
End Sub
End Structure
Public Class RasterBitmap
Private m_pixels() As Rgb
Private m_width As Integer
Public ReadOnly Property Width As Integer
Get
Return m_width
End Get
End Property
Private m_height As Integer
Public ReadOnly Property Height As Integer
Get
Return m_height
End Get
End Property
Public Sub New(ByVal width As Integer, ByVal height As Integer)
m_pixels = New Rgb(width * height - 1) {}
m_width = width
m_height = height
End Sub
Public Sub Clear(ByVal color As Rgb)
For i As Integer = 0 To m_pixels.Length - 1
m_pixels(i) = color
Next
End Sub
Public Sub SetPixel(ByVal x As Integer, ByVal y As Integer, ByVal color As Rgb)
m_pixels((y * m_width) + x) = color
End Sub
Public Function GetPixel(ByVal x As Integer, ByVal y As Integer) As Rgb
Return m_pixels((y * m_width) + x)
End Function
End Class
Wren
The above library's ImageData class fits the bill here (version 1.3.0 or later).
import "graphics" for Canvas, ImageData, Color
import "dome" for Window
class Game {
static bmpCreate(name, w, h) { ImageData.create(name, w, h) }
static bmpFill(name, col) {
var image = ImageData[name]
for (x in 0...image.width) {
for (y in 0...image.height) image.pset(x, y, col)
}
}
static bmpPset(name, x, y, col) { ImageData[name].pset(x, y, col) }
static bmpPget(name, x, y) { ImageData[name].pget(x, y) }
static init() {
Window.title = "Bitmap"
var size = 600
Window.resize(size, size)
Canvas.resize(size, size)
var bmp = bmpCreate("rcbmp", size/2, size/2)
bmpFill("rcbmp", Color.yellow)
bmpPset("rcbmp", size/4, size/4, Color.blue) // 'blue' is #29ADFF on the default palette
var col = bmpPget("rcbmp", size/4, size/4)
System.print(col.toString) // check it's blue - alpha component (FF) will also be shown
bmp.draw(150, 150)
}
static update() {}
static draw(alpha) {}
}
- Output:
Color (#29ADFFFF)
Xojo
Function CreatePicture(width As Integer, height As Integer) As Picture
Return New Picture(width, height)
End Function
Sub FillPicture(ByRef p As Picture, FillColor As Color)
p.Graphics.ForeColor = FillColor
p.Graphics.FillRect(0, 0, p.Width, p.Height)
End Sub
Function GetPixelColor(p As Picture, x As Integer, y As Integer) As Color
Return p.RGBSurface.Pixel(x, y)
End Function
Sub SetPixelColor(p As Picture, x As Integer, y As Integer, pColor As Color)
p.RGBSurface.Pixel(x, y) = pColor
End Sub
XPL0
include c:\cxpl\codes; \include 'code' declarations
def Width=180, Height=135, Color=$123456;
int X, Y;
[SetVid($112); \set display for 640x480 graphics in 24-bit RGB color
for Y:= 0 to Height-1 do \fill area with Color one pixel at a time
for X:= 0 to Width-1 do \(this takes 4.12 ms on a Duron 850)
Point(X, Y, Color);
Move(60, 60); HexOut(6, ReadPix(0,0)); \show color of pixel at 0,0
X:= ChIn(1); \wait for keystroke
SetVid(3); \restore display to normal text mode
]Yabasic
// Rosetta Code problem: http://rosettacode.org/wiki/Bitmap
// by Galileo, 07/2022
open window 200, 200
backcolor 255, 0, 0 // red
clear window
color 0, 255, 0 // green
dot 100, 100
c$ = getbit$(100, 100, 100, 100) // get color area 1x1 pixel
print c$- Output:
rgb 1,1:00ff00 ---Program done, press RETURN---
zkl
This solution creates a PPM image. No error checking or clipping.
class PPM{ // (0,0) is logically bottom left
fcn init(width,height){
sz:=width*height*3;
var [const]
data=sz.pump(Data(sz),0), // initialize to Black (RGB=000)
w=width, h=height;
}
fcn fill(rgb){
sz:=data.len()/3;
data.clear(); sz.pump(data,T(Void,rgb.toBigEndian(3)));
}
fcn __sGet(x,y) { data.toBigEndian(3*y*w + 3*x,3); } //ppm[x,y]
fcn __sSet(rbg,x,y){ data[3*y*w + 3*x,3]=rbg.toBigEndian(3); } //ppm[x,y]=rgb
fcn write(out){ // write bottom to top to move (0,0) from bottom left to bottom left
out.write("P6\n#rosettacode PPM\n%d %d\n255\n".fmt(w,h));
[h-1..0, -1].pump(out,'wrap(h){ data.seek(3*h*w); data.read(3*w) });
out.close();
}
}ppm:=PPM(256,256);
ppm.fill(0x00FF88);
foreach x in ([50..200]){ ppm[x,50]=0xff|00|00; } // horizontal red line
ppm.write(File("foo.ppm","wb"));- Output:
$ zkl hexDump foo.ppm | less 0: 50 36 0a 23 72 6f 73 65 | 74 74 61 63 6f 64 65 20 P6.#rosettacode 16: 50 50 4d 0a 32 35 36 20 | 32 35 36 0a 32 35 35 0a PPM.256 256.255. 32: 00 ff 88 00 ff 88 00 ff | 88 00 ff 88 00 ff 88 00 ................ 48: ff 88 00 ff 88 00 ff 88 | 00 ff 88 00 ff 88 00 ff ................ 64: 88 00 ff 88 00 ff 88 00 | ff 88 00 ff 88 00 ff 88 ................ 80: 00 ff 88 00 ff 88 00 ff | 88 00 ff 88 00 ff 88 00 ................ ...
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