Draw pixel 2: Difference between revisions

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Revision as of 00:31, 12 August 2022

Task

Create a window and draw a pixel in it, subject to the following:

the window is 640 x 480
the color of the pixel must be yellow (255,255,0)
the position of the pixel is random

C

Same as the Draw_a_pixel task, uses the random number functions of stdlib.h to plot a random point. Requires the WinBGIm library. <lang C>

include<graphics.h>
include<stdlib.h>
include<time.h>

int main() { srand(time(NULL));

initwindow(640,480,"Yellow Random Pixel");

putpixel(rand()%640,rand()%480,YELLOW);

getch();

return 0; } </lang>

FreeBASIC

<lang freebasic>' version 04-07-2018 ' compile with: fbc -s console ' or: fbc -s gui

Screen 18, 24 ' Screen 18: 640x480, 24bit colordepth 'ScreenRes 640, 480, 24 ' Screenres: 640x480, 24bit colordepth

If ScreenPtr = 0 Then

   Print "Error setting video mode!"
   End

End If

Randomize Timer Dim As UInteger x = Rnd * 640, y = Rnd * 480

PSet (x, y), RGB(255,255,0) ' yellow

' empty keyboard buffer While Inkey <> "" : Wend WindowTitle "0, 0 is top left, pixel is at " & x & ", " & y & " hit any key to end program" Sleep End</lang>

Go

<lang go>package main

import (

   "fmt"
   "image"
   "image/color"
   "image/draw"
   "math/rand"
   "time"

)

func main() {

   rect := image.Rect(0, 0, 640, 480)
   img := image.NewRGBA(rect)

   // Use blue background, say.
   blue := color.RGBA{0, 0, 255, 255}
   draw.Draw(img, rect, &image.Uniform{blue}, image.ZP, draw.Src)

   // Set color of a random pixel to yellow
   yellow := color.RGBA{255, 255, 0, 255}
   width := img.Bounds().Dx()
   height := img.Bounds().Dy()
   rand.Seed(time.Now().UnixNano())
   x := rand.Intn(width)
   y := rand.Intn(height)
   img.Set(x, y, yellow)

   // Check there's exactly one random yellow pixel.
   cmap := map[color.Color]string{blue: "blue", yellow: "yellow"}
   for i := 0; i < width; i++ {
       for j := 0; j < height; j++ {
           c := img.At(i, j)
           if cmap[c] == "yellow" {
               fmt.Printf("The color of the pixel at (%d, %d) is yellow\n", i, j)
           }
       }
   }

}</lang>

Output:

Sample output:

The color of the pixel at (525, 163) is yellow

See also Draw a pixel. Note that this pixel will be nearly invisible on most screens. There's very low contrast between yellow and white, and single pixels may be difficult to see on "modern" hardware. Remedying these visual problems would require going outside the requirements of the task. You might change the color, for example to black with glrgb 0 0 0 and/or changing the radius to include more pixels, for example 8 with glpen 8 1<lang J>require 'gl2' coinsert 'jgl2' wdTemplate:)n pc Rosetta closeok;cc task isidraw; set task wh 640 480;pshow glpaint glpixel ?640 480 [ glpen 1 1 [ glrgb 255 255 0 [ glclear </lang>

JavaScript

<lang javascript>let w = window.open("", "", "width=640,height=480"); let canvas = document.createElement("canvas"); canvas.width = 640; canvas.height = 480; w.document.body.appendChild(canvas); w.document.body.style.margin = 0; let ctx = canvas.getContext("2d"); ctx.fillStyle = "#FFFF00"; let x = Math.random() * 641; let y = Math.random() * 481; ctx.fillRect(x, y, 1, 1); </lang>

Julia

<lang julia>using Gtk, Graphics

const can = @GtkCanvas() const win = GtkWindow(can, "Draw a Pixel 2", 640, 480)

draw(can) do widget

   ctx = getgc(can)
   set_source_rgb(ctx, 255, 255, 0)
   x = rand(collect(1:639))
   y = rand(collect(1:480))
   println("The pixel is at $x, $y.")
   move_to(ctx, x, y)
   line_to(ctx, x + 1, y)
   stroke(ctx)

end

draw(can) show(can) const cond = Condition() endit(w) = notify(cond) signal_connect(endit, win, :destroy) wait(cond) </lang>

Kotlin

This is a variation of the Draw a pixel task and so therefore is the code to accomplish it. <lang scala>// Version 1.2.41

import java.awt.Color import java.awt.Graphics import java.awt.image.BufferedImage import java.util.Random

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 rand = Random()
   val bbs = BasicBitmapStorage(640, 480)
   with (bbs) {
       fill(Color.white) // say
       val x = rand.nextInt(image.width)
       val y = rand.nextInt(image.height)
       setPixel(x, y, Color.yellow)
       // check there's exactly one random yellow pixel
       for (i in 0 until image.width) {
           for (j in 0 until image.height) {
               if (getPixel(i, j) == Color.yellow) {
                   println("The color of the pixel at ($i, $j) is yellow")
               }
           }
       }
   }

}</lang>

Output:

Sample output:

The color of the pixel at (296, 15) is yellow

Nim

Library: SDL2

<lang Nim>import random import sdl2

discard sdl2.init(INIT_EVERYTHING)

let window = createWindow("Pixel", 300, 300, 640, 480, SDL_WINDOW_SHOWN) let renderer = createRenderer(window, -1, Renderer_Accelerated)

randomize() renderer.clear() renderer.setDrawColor((255u8, 255u8, 0u8, 0u8)) let x = rand(639) let y = rand(479) renderer.drawPoint(x.cint, y.cint) renderer.present()

delay(5000)</lang>

Objeck

<lang objeck>use Game.SDL2; use Game.Framework;

class DrawPixel {

   @framework : GameFramework;
 
 function : Main(args : String[]) ~ Nil {
   DrawPixel->New()->Run();
 }
 
 New() {
   @framework := GameFramework->New(640, 480, "RGB");
   @framework->SetClearColor(Color->New(0, 0, 0));
 }

 method : Run() ~ Nil {
   if(@framework->IsOk()) {
     e := @framework->GetEvent();
     
     x := Int->Random(640);
     y := Int->Random(480);
     
     quit := false;
     while(<>quit) {
       @framework->FrameStart();
       @framework->Clear();

       # process input
       while(e->Poll() <> 0) {
         if(e->GetType() = EventType->SDL_QUIT) {
           quit := true;
         };
       };
       
       @framework->GetRenderer()->SetDrawColor(255, 255, 0, 0);
       @framework->GetRenderer()->DrawPoint(x, y);

        @framework->Show();
       @framework->FrameEnd();
     };
   }
   else {
     "--- Error Initializing Game Environment ---"->ErrorLine();
     return;
   };

   leaving {
     @framework->Quit();
   };
 }

}</lang>

Perl

Library: Gtk3

<lang perl>use Gtk3 '-init';

my $width = 640; my $height = 480;

my $window = Gtk3::Window->new(); $window->set_default_size($width, $height); $window->set_border_width(10); $window->set_title("Draw Pixel 2"); $window->set_app_paintable(TRUE);

my $da = Gtk3::DrawingArea->new(); $da->signal_connect('draw' => \&draw_in_drawingarea); $window->add($da); $window->show_all();

Gtk3->main;

sub draw_in_drawingarea {

 my ($widget, $cr, $data) = @_;
 $cr->set_source_rgb(1, 1, 0);
 $cr->set_line_width(1);
 $cr->rectangle( int rand $width , int rand $height, 1, 1);
 $cr->stroke;

}</lang>

Phix

Library: Phix/pGUI

Pixel jumps around randomly, twice a second.

--
-- demo\rosetta\Draw_pixel_2.exw
--
with javascript_semantics
include pGUI.e

Ihandle dlg, canvas
cdCanvas cddbuffer, cdcanvas

function redraw_cb(Ihandle /*ih*/)
    atom {w,h} = IupGetIntInt(canvas, "DRAWSIZE")
    cdCanvasActivate(cddbuffer)
    cdCanvasClear(cddbuffer)
    cdCanvasPixel(cddbuffer, rand(w), rand(h), CD_YELLOW)
    cdCanvasFlush(cddbuffer)
    return IUP_DEFAULT
end function

function map_cb(Ihandle ih)
    cdcanvas = cdCreateCanvas(CD_IUP, ih)
    cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas)
    cdCanvasSetBackground(cddbuffer, CD_BLACK)
    return IUP_DEFAULT
end function

function timer_cb(Ihandle /*ih*/)
    IupUpdate(canvas)
    return IUP_IGNORE
end function

procedure main()
    IupOpen()
    canvas = IupCanvas("RASTERSIZE=240x250")
    IupSetCallbacks(canvas, {"MAP_CB", Icallback("map_cb"),
                             "ACTION", Icallback("redraw_cb")})
    dlg = IupDialog(canvas,`TITLE="Draw pixel"`)
    IupShow(dlg)
    IupSetAttribute(canvas, "RASTERSIZE", NULL)
    Ihandle timer = IupTimer(Icallback("timer_cb"), 500) -- (2 fps)
    if platform()!=JS then
        IupMainLoop()
        IupClose()
    end if
end procedure

main()

Processing

<lang java> //Aamrun, 26th June 2022

size(640,480);

stroke(#ffff00);

ellipse(random(640),random(480),1,1); </lang>

Python

Works with: Python version 2.7

Library: Tkinter

Library: random

<lang python>import Tkinter,random def draw_pixel_2 ( sizex=640,sizey=480 ):

   pos  = random.randint( 0,sizex-1 ),random.randint( 0,sizey-1 )
   root = Tkinter.Tk()
   can  = Tkinter.Canvas( root,width=sizex,height=sizey,bg='black' )
   can.create_rectangle( pos*2,outline='yellow' )
   can.pack()
   root.title('press ESCAPE to quit')
   root.bind('<Escape>',lambda e : root.quit())
   root.mainloop()

draw_pixel_2()</lang>

Racket

<lang racket>#lang racket/gui

(define WIDTH 640) (define HEIGHT 480) (define COLOR (make-color 255 255 0)) (define BACKGROUND-COLOR (make-color 0 0 0))

(define frame (new frame%

                  [label "Draw Pixel"]
                  [width WIDTH]
                  [height HEIGHT]))

(new canvas% [parent frame]

    [paint-callback
     (λ (canvas dc)
       (send dc set-background BACKGROUND-COLOR)
       (send dc clear)
       (send dc set-pen COLOR 1 'solid)
       (send dc draw-point (random WIDTH) (random HEIGHT)))])

(send frame show #t)</lang>

Raku

(formerly Perl 6)

Works with: Rakudo version 2018.05

Coordinates of random pixel displayed in window title. To make the single pixel show up better I filled in the drawing area background with black to get better contrast.

<lang perl6>use GTK::Simple; use GTK::Simple::DrawingArea; use Cairo; my ($w, $h) = 640, 480; my ($x, $y) = (^$w).pick, (^$h).pick;

my $app = GTK::Simple::App.new(:title("Draw Pixel 2 @ $x,$y")); my $da = GTK::Simple::DrawingArea.new; gtk_simple_use_cairo;

$app.set-content( $da ); $app.border-width = 5; $da.size-request($w, $h);

sub rect-do( $d, $ctx ) {

   given $ctx {
       .rgb(0, 0, 0);
       .rectangle(0, 0, $w, $h);
       .fill;
       .rgb(1, 1, 0);
       .rectangle($x, $y, 1, 1);
       .fill;
   }

}

my $ctx = $da.add-draw-handler( &rect-do ); $app.run;</lang>

Ring

<lang ring># Project : Draw pixel 2

load "guilib.ring"

new qapp {

      nwidth = 320
      nheight= 240
      win1 = new qwidget() {
                 setwindowtitle("Draw Pixel 2")
                 setgeometry(100,100,640,480)
                 label1 = new qlabel(win1) {
                             setgeometry(10,10,640,480)
                             settext("")
                 }
                 new qpushbutton(win1) {
                        setgeometry(200,400,100,30)
                        settext("draw")
                        setclickevent("draw()")
                 }
                 new qpushbutton(win1) {
                        setgeometry(300,400,100,30)
                        settext("get pixel color")
                        setclickevent("PixelColor()")
                 }
                 show()
      }
      exec()

}

func draw()

       p1 = new qpicture()
       color = new qcolor() {
                  setrgb(255,255,0,255)
                 }
       pen = new qpen() {
                 setcolor(color)
                 setwidth(10)
                 }
       new qpainter() {
              begin(p1)
              setpen(pen)
              x = random(nwidth-1) + 1
              y = random(nheight-1) + 1
              see "x = " + x + " y = " + y + nl
              drawpoint(x,y)
              endpaint()
              }
              label1 { setpicture(p1) show() }

func PixelColor()

      oapp = new qapp(0,null)  {
                 screen = win1.windowhandle().screen()
                 pixmap = screen.grabwindow(0,0,0,-1,-1)
                 image = pixmap.toimage()
                 color = image.pixel(100,100)
                 mycolor = new qcolor()
                 mycolor.setrgb(255,255,0,255)
                 see nl+"red : " + mycolor.red() + nl
                 see "green : " + mycolor.green() + nl
                 see "blue : " + mycolor.blue() + nl
                 }</lang>

Outputimage:

Draw pixel 2

Scala

Java Swing Interoperability

Output:

See it yourself by running in your browser either by Scastie (remote JVM).

Library: Scala Java Swing interoperability

Library: Scala Test provided

Library: Scala Javanese style

Library: Scastie qualified

Works with: Scala version 2.13

<lang Scala>import java.awt.image.BufferedImage import java.awt.Color import scala.language.reflectiveCalls

object RgbBitmap extends App {

 // 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
 }

 class RgbBitMap(val dim: (Int, Int)) {
   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)
   }

   def width = dim._1
   def height = dim._2
 }

 private val (x,y) = (util.Random.nextInt(50), util.Random.nextInt(60))

 img0.fill(Color.CYAN)
 img0.setPixel(x, y, Color.BLUE)
 // Testing in Java style
 assert(img0.getPixel(x, y) == Color.BLUE)
 assert(img0.width == 50)
 assert(img0.height == 60)
 println("Tests successfully completed with no errors found.")

}</lang>

Wren

Library: DOME

<lang ecmascript>import "dome" for Window import "graphics" for Canvas, Color import "random" for Random

class Game {

   static init() {
       Window.title = "Draw a pixel 2"
       Window.resize(320, 240)
       Canvas.resize(320, 240)
       var yellow = Color.rgb(255, 255, 0)
       var rand = Random.new()
       var randX = rand.int(320)
       var randY = rand.int(240)
       Canvas.pset(randX, randY, yellow)
   }

   static update() {}

   static draw(dt) {}

   static getRGB(col) { "{%(col.r), %(col.g), %(col.b)}" }

}</lang>

XPL0

This is all that's required on the Raspberry Pi version of XPL0. <lang XPL0>[SetFB(640, 480, 24); Point(Ran(640), Ran(480), $FFFF00)]</lang>

@@ Line 268: / Line 268: @@
 </pre>
+=={{header|J}}==
+See also [[Draw_a_pixel#J|Draw a pixel]]. Note that this pixel will be nearly invisible on most screens. There's very low contrast between yellow and white, and single pixels may be difficult to see on "modern" hardware. Remedying these visual problems would require going outside the requirements of the task. You might change the color, for example to black with <code>glrgb 0 0 0</code> and/or changing the radius to include more pixels, for example 8 with <code>glpen 8 1</code><lang J>require 'gl2'
+coinsert 'jgl2'
+wd{{)n pc Rosetta closeok;cc task isidraw; set task wh 640 480;pshow}}
+glpaint glpixel ?640 480 [ glpen 1 1 [ glrgb 255 255 0 [ glclear ''</lang>
 =={{header|javascript}}==
 <lang javascript>let w = window.open("", "", "width=640,height=480");

Draw pixel 2: Difference between revisions

Revision as of 00:31, 12 August 2022

Ada

C

Delphi

Factor

FreeBASIC

Go

J

JavaScript

Julia

Kotlin

Nim

Objeck

Perl

Phix

Processing

Python

Racket

Raku

Ring

Scala

Java Swing Interoperability

Wren

XPL0