Bitmap/Bézier curves/Cubic: Difference between revisions

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[[Category:Geometry]]

Using the data storage type defined [[Basic_bitmap_storage|on this page]] for raster images, and the <tt>draw_line</tt> function defined in [[Bresenham's_line_algorithm|this other one]], draw a '''cubic bezier curve'''

([[wp:Bezier_curves#Cubic_B.C3.A9zier_curves|definition on Wikipedia]]).

=={{header|11l}}==

<syntaxhighlight lang=11l>T Colour

<syntaxhighlight lang="11l">T Colour

Byte r, g, b

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+-----------------+

</pre>

=={{header|Action!}}==

<syntaxhighlight lang=~~Action~~!>INCLUDE "H6:RGBLINE.ACT" ;from task Bresenham's line algorithm

<syntaxhighlight lang="action!">INCLUDE "H6:RGBLINE.ACT" ;from task Bresenham's line algorithm

INCLUDE "H6:REALMATH.ACT"

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[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/B%C3%A9zier_curves_cubic.png Screenshot from Atari 8-bit computer]

=={{header|Ada}}==

<syntaxhighlight lang=ada>procedure Cubic_Bezier

<syntaxhighlight lang="ada">procedure Cubic_Bezier

( Picture : in out Image;

P1, P2, P3, P4 : Point;

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end Cubic_Bezier;</syntaxhighlight>

The following test

<syntaxhighlight lang=ada> X : Image (1..16, 1..16);

<syntaxhighlight lang="ada"> X : Image (1..16, 1..16);

begin

Fill (X, White);

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H

</pre>

=={{header|ALGOL 68}}==

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{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-2.6 algol68g-2.6].}}

{{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of '''format'''[ted] ''transput''.}}

'''File: prelude/Bitmap/Bezier_curves/Cubic.a68'''<syntaxhighlight lang=algol68># -*- coding: utf-8 -*- #

'''File: prelude/Bitmap/Bezier_curves/Cubic.a68'''<syntaxhighlight lang="algol68"># -*- coding: utf-8 -*- #

cubic bezier OF class image :=

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END # cubic bezier #;

SKIP</syntaxhighlight>'''File: test/Bitmap/Bezier_curves/Cubic.a68'''<syntaxhighlight lang=algol68>#!/usr/bin/a68g --script #

SKIP</syntaxhighlight>'''File: test/Bitmap/Bezier_curves/Cubic.a68'''<syntaxhighlight lang="algol68">#!/usr/bin/a68g --script #

# -*- coding: utf-8 -*- #

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000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

</pre>

=={{header|BBC BASIC}}==

[[Image:beziercubic_bbc.gif|right]]

<syntaxhighlight lang=bbcbasic> Width% = 200

<syntaxhighlight lang="bbcbasic"> Width% = 200

Height% = 200

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LINE x%*2,y%*2,x%*2,y%*2

ENDPROC</syntaxhighlight>

=={{header|C}}==

"Interface" <tt>imglib.h</tt>.

<syntaxhighlight lang=c>void cubic_bezier(

<syntaxhighlight lang="c">void cubic_bezier(

image img,

unsigned int x1, unsigned int y1,

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color_component b );</syntaxhighlight>

<syntaxhighlight lang=c>#include <math.h>

<syntaxhighlight lang="c">#include <math.h>

/* number of segments for the curve */

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#undef plot

#undef line</syntaxhighlight>

=={{header|D}}==

This solution uses two modules, from the Grayscale image and Bresenham's line algorithm Tasks.

<syntaxhighlight lang=d>import grayscale_image, bitmap_bresenhams_line_algorithm;

<syntaxhighlight lang="d">import grayscale_image, bitmap_bresenhams_line_algorithm;

struct Pt { int x, y; } // Signed.

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.................

.................</pre>

=={{header|F Sharp|F#}}==

/// Uses Vector<float> from Microsoft.FSharp.Math (in F# PowerPack)

module CubicBezier

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</syntaxhighlight>

// For rendering..

let drawPoints points (canvas:System.Windows.Controls.Canvas) =

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points |> List.fold renderPoint points.Head

</syntaxhighlight>

=={{header|Factor}}==

The points should probably be in a sequence...

<syntaxhighlight lang=factor>USING: arrays kernel locals math math.functions

<syntaxhighlight lang="factor">USING: arrays kernel locals math math.functions

rosettacode.raster.storage sequences ;

IN: rosettacode.raster.line

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points-to-lines

{R,G,B} swap image draw-lines ;</syntaxhighlight>

=={{header|FBSL}}==

Windows' graphics origin is located at the bottom-left corner of device bitmap.

'''Translation of BBC BASIC using pure FBSL's built-in graphics functions:'''

<syntaxhighlight lang=qbasic>#DEFINE WM_LBUTTONDOWN 513

<syntaxhighlight lang="qbasic">#DEFINE WM_LBUTTONDOWN 513

#DEFINE WM_CLOSE 16

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END SUB</syntaxhighlight>

'''Output:''' [[File:FBSLBezierCube.PNG]]

=={{header|Fortran}}==

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This subroutine should go inside the <code>RCImagePrimitive</code> module (see [[Bresenham's line algorithm]])

<syntaxhighlight lang=fortran>subroutine cubic_bezier(img, p1, p2, p3, p4, color)

<syntaxhighlight lang="fortran">subroutine cubic_bezier(img, p1, p2, p3, p4, color)

type(rgbimage), intent(inout) :: img

type(point), intent(in) :: p1, p2, p3, p4

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end subroutine cubic_bezier</syntaxhighlight>

=={{header|FreeBASIC}}==

<syntaxhighlight lang=freebasic>' version 01-11-2016

<syntaxhighlight lang="freebasic">' version 01-11-2016

' compile with: fbc -s console

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Sleep

End</syntaxhighlight>

=={{header|Go}}==

<syntaxhighlight lang=go>package raster

<syntaxhighlight lang="go">package raster

const b3Seg = 30

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Demonstration program:

[[File:GoBez3.png|thumb|right]]

<syntaxhighlight lang=go>package main

<syntaxhighlight lang="go">package main

import (

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}

}</syntaxhighlight>

=={{header|J}}==

'''Solution:'''

See the [[J:Essays/Bernstein Polynomials|Bernstein Polynomials essay]] on the [[J:|J Wiki]].

Uses code from [[Basic_bitmap_storage#J|Basic bitmap storage]], [[Bresenham's_line_algorithm#J|Bresenham's line algorithm]] and [[Midpoint_circle_algorithm#J|Midpoint circle algorithm]].

<syntaxhighlight lang=j>require 'numeric'

<syntaxhighlight lang="j">require 'numeric'

bik=: 2 : '((*&(u!v))@(^&u * ^&(v-u)@-.))'

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'''Example usage:'''

<syntaxhighlight lang=j>myimg=: 0 0 255 makeRGB 300 300

<syntaxhighlight lang="j">myimg=: 0 0 255 makeRGB 300 300

]randomctrlpts=: ,3 2 ?@$ }:$ myimg NB. 3 control points - quadratic

]randomctrlpts=: ,4 2 ?@$ }:$ myimg NB. 4 control points - cubic

myimg=: ((2 ,.~ _2]\randomctrlpts);255 0 255) drawCircles myimg NB. draw control points

viewRGB (randomctrlpts; 255 255 0) drawBezier myimg NB. display image with bezier line</syntaxhighlight>

=={{header|JavaScript}}==

function draw() {

var canvas = document.getElementById("container");

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}

</syntaxhighlight>

=={{header|Julia}}==

<syntaxhighlight lang=julia>using Images

<syntaxhighlight lang="julia">using Images

function cubicbezier!(xy::Matrix,

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xy = [16 1; 1 4; 3 16; 15 11]

cubicbezier!(xy)</syntaxhighlight>

=={{header|Kotlin}}==

This incorporates code from other relevant tasks in order to provide a runnable example.

<syntaxhighlight lang=scala>// Version 1.2.40

<syntaxhighlight lang="scala">// Version 1.2.40

import java.awt.Color

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}

}</syntaxhighlight>

=={{header|Lua}}==

Starting with the code from [[Bitmap/Bresenham's line algorithm#Lua|Bitmap/Bresenham's line algorithm]], then extending:

<syntaxhighlight lang=lua>Bitmap.cubicbezier = function(self, x1, y1, x2, y2, x3, y3, x4, y4, nseg)

nseg = nseg or 10

local prevx, prevy, currx, curry

for i = 0, nseg do

local t = i / nseg

local a, b, c, d = (1-t)^3, 3*t*(1-t)^2, 3*t^2*(1-t), t^3

prevx, prevy = currx, curry

currx = math.floor(a * x1 + b * x2 + c * x3 + d * x4 + 0.5)

curry = math.floor(a * y1 + b * y2 + c * y3 + d * y4 + 0.5)

if i > 0 then

self:line(prevx, prevy, currx, curry)

end

local bitmap = Bitmap(61,21)

bitmap:clear()

bitmap:cubicbezier( 1,1, 15,41, 45,-20, 59,19 )

bitmap:render({[0x000000]='.', [0xFFFFFFFF]='X'})</syntaxhighlight>

<pre>.............................................................

.X...........................................................

..X..........................................................

...X.........................................................

...X.....................................XXXXX...............

....X.................................XXX.....XXXX...........

....X..............................XXX............X..........

.....X...........................XX................X.........

.....X.........................XX...................X........

......X.....................XXX......................XX......

.......X..................XX..........................X......

........X...............XX.............................X.....

.........X...........XXX................................X....

..........XXXX....XXX...................................X....

..............XXXX.......................................X...

.........................................................X...

..........................................................X..

...........................................................X.

.............................................................</pre>

=={{header|Lambdatalk}}==

Drawing a cubic bezier curve out of any SVG or CANVAS frame.

1) interpolating 4 points

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</syntaxhighlight>

=={{header|Lua}}==

Starting with the code from [[Bitmap/Bresenham's line algorithm#Lua|Bitmap/Bresenham's line algorithm]], then extending:

<syntaxhighlight lang="lua">Bitmap.cubicbezier = function(self, x1, y1, x2, y2, x3, y3, x4, y4, nseg)