Data commit

2023-07-01 11:58:00 -04:00 · 2023-07-01 11:58:00 -04:00 · cb5bb5e222
commit cb5bb5e222
parent 7387c8f97b
199093 changed files with 3378972 additions and 0 deletions
--- a/Task/Color-wheel/00-META.yaml
+++ b/Task/Color-wheel/00-META.yaml
@ -0,0 +1,3 @@
+---
+from: http://rosettacode.org/wiki/Color_wheel
+note: Basic language learning
--- a/Task/Color-wheel/00-TASK.txt
+++ b/Task/Color-wheel/00-TASK.txt
@ -0,0 +1,7 @@
+;Task:
+Write a function to draw a [[wp:HSL_and_HSV|HSV]] color wheel completely with code. 
+
+This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel &nbsp; (as procedurally drawing is super slow). This does help you understand how color wheels work and this can easily be used to determine a color value based on a position within a circle.
+
+
+
--- a/Task/Color-wheel/AppleScript/color-wheel.applescript
+++ b/Task/Color-wheel/AppleScript/color-wheel.applescript
@ -0,0 +1 @@
+choose color default color {0, 0, 0, 0}
--- a/Task/Color-wheel/Applesoft-BASIC/color-wheel.basic
+++ b/Task/Color-wheel/Applesoft-BASIC/color-wheel.basic
@ -0,0 +1,29 @@
+ 100  LET R = 3.1415926535 / 180
+ 110  LET YO = 20
+ 120  LET XO = YO
+ 130  LET MS =  INT (YO * 7 / 8)
+ 140  LET O$ = "1111111111.1111111110.1111011110.1101110110.1101010110.1010101010.0010101001.0010001001.0000100001.0000000001.0000000000"
+ 150  GR
+ 160  FOR S = 0 TO MS
+ 170      LET D = S / MS
+ 180      LET P$ =  MID$ (O$, INT (D * 10) * 11 + 1,11)
+ 190      LET SY = S
+ 200      LET SX = S * 4 / 7
+ 210      LET P = 0
+ 220      FOR I = 0 TO 360
+ 230          LET X = XO +  SIN (I * R) * SX
+ 240          LET Y = YO +  COS (I * R) * SY
+ 250          LET W = 15
+ 260          IF I >  = 30 - 22.4 AND I < 30 + 22.5 THEN  COLOR= 9
+ 270          IF I >  = 75 - 22.5 AND I < 75 + 22.5 THEN  COLOR= 13
+ 280          IF I >  = 120 - 22.5 AND I < 120 + 22.5 THEN  COLOR= 12:W = 14
+ 290          IF I >  = 165 - 22.5 AND I < 165 + 22.5 THEN  COLOR= 7:W = 14
+ 300          IF I >  = 210 - 22.5 AND I < 210 + 22.5 THEN  COLOR= 6
+ 310          IF I >  = 255 - 22.5 AND I < 255 + 22.5 THEN  COLOR= 2
+ 320          IF I >  = 300 - 22.5 AND I < 300 + 22.5 THEN  COLOR= 3:W = 11
+ 330          IF I >  = 345 - 22.5 OR I < 345 + 22.5 - 360 THEN  COLOR= 1:W = 11
+ 340          IF D < .2 THEN W = 15
+ 350          IF  RND (1) < D THEN W = 15
+ 360          IF  VAL ( MID$ (P$,P + 1,1)) THEN  COLOR= W
+ 370          IF  SCRN( X,Y) = 0 THEN  PLOT X,Y:P = P + 1: IF P >  = 9 THEN P = 0
+ 380  NEXT I,S
--- a/Task/Color-wheel/C++/color-wheel-1.cpp
+++ b/Task/Color-wheel/C++/color-wheel-1.cpp
@ -0,0 +1,70 @@
+// colorwheelwidget.cpp
+#include "colorwheelwidget.h"
+#include <QPainter>
+#include <QPaintEvent>
+#include <cmath>
+
+namespace {
+
+QColor hsvToRgb(int h, double s, double v) {
+    double hp = h/60.0;
+    double c = s * v;
+    double x = c * (1 - std::abs(std::fmod(hp, 2) - 1));
+    double m = v - c;
+    double r = 0, g = 0, b = 0;
+    if (hp <= 1) {
+        r = c;
+        g = x;
+    } else if (hp <= 2) {
+        r = x;
+        g = c;
+    } else if (hp <= 3) {
+        g = c;
+        b = x;
+    } else if (hp <= 4) {
+        g = x;
+        b = c;
+    } else if (hp <= 5) {
+        r = x;
+        b = c;
+    } else {
+        r = c;
+        b = x;
+    }
+    r += m;
+    g += m;
+    b += m;
+    return QColor(r * 255, g * 255, b * 255);
+}
+
+}
+
+ColorWheelWidget::ColorWheelWidget(QWidget *parent)
+    : QWidget(parent) {
+    setWindowTitle(tr("Color Wheel"));
+    resize(400, 400);
+}
+
+void ColorWheelWidget::paintEvent(QPaintEvent *event) {
+    QPainter painter(this);
+    painter.setRenderHint(QPainter::Antialiasing);
+    const QColor backgroundColor(0, 0, 0);
+    const QColor white(255, 255, 255);
+    painter.fillRect(event->rect(), backgroundColor);
+    const int margin = 10;
+    const double diameter = std::min(width(), height()) - 2*margin;
+    QPointF center(width()/2.0, height()/2.0);
+    QRectF rect(center.x() - diameter/2.0, center.y() - diameter/2.0,
+                diameter, diameter);
+    for (int angle = 0; angle < 360; ++angle) {
+        QColor color(hsvToRgb(angle, 1.0, 1.0));
+        QRadialGradient gradient(center, diameter/2.0);
+        gradient.setColorAt(0, white);
+        gradient.setColorAt(1, color);
+        QBrush brush(gradient);
+        QPen pen(brush, 1.0);
+        painter.setPen(pen);
+        painter.setBrush(brush);
+        painter.drawPie(rect, angle * 16, 16);
+    }
+}
--- a/Task/Color-wheel/C++/color-wheel-2.cpp
+++ b/Task/Color-wheel/C++/color-wheel-2.cpp
@ -0,0 +1,15 @@
+// colorwheelwidget.h
+#ifndef COLORWHEELWIDGET_H
+#define COLORWHEELWIDGET_H
+
+#include <QWidget>
+
+class ColorWheelWidget : public QWidget {
+    Q_OBJECT
+public:
+    ColorWheelWidget(QWidget *parent = nullptr);
+protected:
+    void paintEvent(QPaintEvent *event) override;
+};
+
+#endif // COLORWHEELWIDGET_H
--- a/Task/Color-wheel/C++/color-wheel-3.cpp
+++ b/Task/Color-wheel/C++/color-wheel-3.cpp
@ -0,0 +1,10 @@
+// main.cpp
+#include "colorwheelwidget.h"
+#include <QApplication>
+
+int main(int argc, char *argv[]) {
+    QApplication app(argc, argv);
+    ColorWheelWidget widget;
+    widget.show();
+    return app.exec();
+}
--- a/Task/Color-wheel/C-sharp/color-wheel.cs
+++ b/Task/Color-wheel/C-sharp/color-wheel.cs
@ -0,0 +1,66 @@
+// constructor of main window
+// in MainWindow.xaml just create <Image Name="imgMain" />
+public MainWindow()
+{
+    InitializeComponent();
+    RenderOptions.SetBitmapScalingMode(imgMain, BitmapScalingMode.HighQuality);
+    imgMain.Source = new WriteableBitmap(480, 480, 96, 96, PixelFormats.Bgr32, null);
+    // using slider you can change saturation and call DrawHue with different level
+    DrawHue(100);
+}
+
+void DrawHue(int saturation)
+{
+    var bmp = (WriteableBitmap)imgMain.Source;
+
+    int centerX = (int)bmp.Width / 2;
+    int centerY = (int)bmp.Height / 2;
+    int radius = Math.Min(centerX, centerY);
+    int radius2 = radius - 40;
+
+    bmp.Lock();
+    unsafe{
+        var buf = bmp.BackBuffer;
+        IntPtr pixLineStart;
+        for(int y=0; y < bmp.Height; y++){
+            pixLineStart = buf + bmp.BackBufferStride * y;
+            double dy = (y - centerY);
+            for(int x=0; x < bmp.Width; x++){
+                double dx = (x - centerX);
+                double dist = Math.Sqrt(dx * dx + dy * dy);
+                if (radius2 <= dist && dist <= radius) {
+                    double theta = Math.Atan2(dy, dx);
+                    double hue = (theta + Math.PI) / (2.0 * Math.PI);
+                    *((int*)(pixLineStart + x * 4)) = HSB_to_RGB((int)(hue * 360), saturation, 100);
+                }
+            }
+        }
+    }
+    bmp.AddDirtyRect(new Int32Rect(0, 0, 480, 480));
+    bmp.Unlock();
+}
+
+static int HSB_to_RGB(int h, int s, int v)
+{
+    var rgb = new int[3];
+
+    var baseColor = (h + 60) % 360 / 120;
+    var shift = (h + 60) % 360 - (120 * baseColor + 60 );
+    var secondaryColor = (baseColor + (shift >= 0 ? 1 : -1) + 3) % 3;
+
+    //Setting Hue
+    rgb[baseColor] = 255;
+    rgb[secondaryColor] = (int) ((Math.Abs(shift) / 60.0f) * 255.0f);
+
+    //Setting Saturation
+    for (var i = 0; i < 3; i++)
+        rgb[i] += (int) ((255 - rgb[i]) * ((100 - s) / 100.0f));
+
+    //Setting Value
+    for (var i = 0; i < 3; i++)
+        rgb[i] -= (int) (rgb[i] * (100-v) / 100.0f);
+
+    return RGB2int(rgb[0], rgb[1], rgb[2]);
+}
+
+public static int RGB2int(int r, int g, int b) => r << 16 | g << 8 | b;
--- a/Task/Color-wheel/Delphi/color-wheel.delphi
+++ b/Task/Color-wheel/Delphi/color-wheel.delphi
@ -0,0 +1,95 @@
+program Color_wheel;
+
+{$APPTYPE CONSOLE}
+
+uses
+  Winapi.Windows,
+  System.SysUtils,
+  Vcl.Graphics,
+  System.Math,
+  Vcl.Imaging.pngimage;
+
+const
+  TAU = 2 * PI;
+
+function HSBtoColor(hue, sat, bri: Double): TColor;
+var
+  f, h: Double;
+  u, p, q, t: Byte;
+begin
+  u := Trunc(bri * 255 + 0.5);
+  if sat = 0 then
+    Exit(rgb(u, u, u));
+
+  h := (hue - Floor(hue)) * 6;
+  f := h - Floor(h);
+  p := Trunc(bri * (1 - sat) * 255 + 0.5);
+  q := Trunc(bri * (1 - sat * f) * 255 + 0.5);
+  t := Trunc(bri * (1 - sat * (1 - f)) * 255 + 0.5);
+
+  case Trunc(h) of
+    0:
+      result := rgb(u, t, p);
+    1:
+      result := rgb(q, u, p);
+    2:
+      result := rgb(p, u, t);
+    3:
+      result := rgb(p, q, u);
+    4:
+      result := rgb(t, p, u);
+    5:
+      result := rgb(u, p, q);
+  else
+    result := clwhite;
+  end;
+
+end;
+
+function ColorWheel(Width, Height: Integer): TPngImage;
+var
+  Center: TPoint;
+  Radius: Integer;
+  x, y: Integer;
+  Hue, dy, dx, dist, theta: Double;
+  Bmp: TBitmap;
+begin
+  Bmp := TBitmap.Create;
+  Bmp.SetSize(Width, Height);
+  with Bmp.Canvas do
+  begin
+    Brush.Color := clWhite;
+    FillRect(ClipRect);
+    Center := ClipRect.CenterPoint;
+    Radius := Center.X;
+    if Center.Y < Radius then
+      Radius := Center.Y;
+    for y := 0 to Height - 1 do
+    begin
+      dy := y - Center.y;
+      for x := 0 to Width - 1 do
+      begin
+        dx := x - Center.x;
+        dist := Sqrt(Sqr(dx) + Sqr(dy));
+        if dist <= Radius then
+        begin
+          theta := ArcTan2(dy, dx);
+          Hue := (theta + PI) / TAU;
+          Pixels[x, y] := HSBtoColor(Hue, 1, 1);
+        end;
+      end;
+    end;
+  end;
+
+  Result := TPngImage.Create;
+  Result.Assign(Bmp);
+  Bmp.Free;
+end;
+
+begin
+  with ColorWheel(500, 500) do
+  begin
+    SaveToFile('ColorWheel.png');
+    Free;
+  end;
+end.
--- a/Task/Color-wheel/FreeBASIC/color-wheel.basic
+++ b/Task/Color-wheel/FreeBASIC/color-wheel.basic
@ -0,0 +1,114 @@
+#include "fbgfx.bi"
+
+Sub HSVtoRGB(h As Single, s As Integer, v As Integer, Byref r As Integer, Byref g As Integer, Byref b As Integer)
+    If s = 0 Then
+        r = v
+        g = v
+        b = v
+        Return
+    End If
+
+    h = h Mod 360
+    Dim As Single hue = h
+
+    Select Case h
+    Case 0f To 51.5f
+        hue = ((hue         ) * (30f / (51.5f          )))
+    Case 51.5f To 122f
+        hue = ((hue -  51.5f) * (30f / (122f   -  51.5f))) + 30
+    Case 122f To 142.5f
+        hue = ((hue -   122f) * (30f / (142.5f -   122f))) + 60
+    Case 142.5f To 165.5f
+        hue = ((hue - 142.5f) * (30f / (165.5f - 142.5f))) + 90
+    Case 165.5f To 192f
+        hue = ((hue - 165.5f) * (30f / (192f   - 165.5f))) + 120
+    Case 192f To 218.5f
+        hue = ((hue -   192f) * (30f / (218.5f -   192f))) + 150
+    Case 218.5f To 247f
+        hue = ((hue - 218.5f) * (30f / (247f   - 218.5f))) + 180
+    Case 247f To 275.5f
+        hue = ((hue -   247f) * (30f / (275.5f -   247f))) + 210
+    Case 275.5f To 302.5f
+        hue = ((hue - 275.5f) * (30f / (302.5f - 275.5f))) + 240
+    Case 302.5f To 330f
+        hue = ((hue - 302.5f) * (30f / (330f   - 302.5f))) + 270
+    Case 330f To 344.5f
+        hue = ((hue -   330f) * (30f / (344.5f -   330f))) + 300
+    Case 344.5f To 360f
+        hue = ((hue - 344.5f) * (30f / (360f   - 344.5f))) + 330
+    End Select
+    h = hue
+
+    h = h Mod 360
+
+    Dim As Single h1 = h / 60
+    Dim As Integer i = Int(h1)
+    Dim As Single f = h1 - i
+    Dim As Integer p = v * (255 - s) / 256
+    Dim As Integer q = v * (255 - f * s) / 256
+    Dim As Integer t = v * (255 - (1 - f) * s) / 256
+
+    Select Case As Const i
+    Case 0
+        r = v
+        g = t
+        b = p
+        Return
+    Case 1
+        r = q
+        g = v
+        b = p
+        Return
+    Case 2
+        r = p
+        g = v
+        b = t
+        Return
+    Case 3
+        r = p
+        g = q
+        b = v
+        Return
+    Case 4
+        r = t
+        g = p
+        b = v
+        Return
+    Case 5
+        r = v
+        g = p
+        b = q
+        Return
+    End Select
+End Sub
+
+Const pi As Single = 4 * Atn(1)
+Const radius = 160
+Const xres = (radius * 2) + 1, yres = xres
+
+Screenres xres, yres, 32
+Windowtitle "Color wheel"
+
+Dim As Integer r,g,b
+Dim As Single dx, dy, dist, angle
+
+Do
+    Screenlock
+    Cls
+    For x As Integer = 0 To (radius * 2) - 1
+        For y As Integer = 0 To (radius * 2) - 1
+            dx = x - radius
+            dy = radius - y
+            dist = Sqr(dx * dx + dy * dy)
+            If dist < radius Then
+                angle = Atan2(dy, dx) * (180/pi)
+                If angle <   0 Then angle += 360
+                If angle > 360 Then angle -= 360
+                HSVtoRGB(angle, (dist / radius) * 255, 255, r, g, b)
+                Pset(x, y), Rgb(r, g, b)
+            End If
+        Next y
+    Next x
+
+    Screenunlock
+Loop Until Inkey = Chr(27)
--- a/Task/Color-wheel/FutureBasic/color-wheel.basic
+++ b/Task/Color-wheel/FutureBasic/color-wheel.basic
@ -0,0 +1,40 @@
+_window = 1
+begin enum output 1
+  _colorwheelImageView
+end enum
+
+void local fn BuildWindow
+  CGRect  r = fn CGRectMake( 0, 0, 400, 400 )
+  window _window, @"Programmatic Color Wheel", r, NSWindowStyleMaskTitled + NSWindowStyleMaskClosable
+
+  r = fn CGRectMake( 20, 20, 360, 360 )
+  imageview _colorwheelImageView, YES, , r, NSImageScaleProportionallyUpOrDown, NSImageAlignCenter, NSImageFrameNone, _window
+end fn
+
+local fn CIImageToImageRef( ciImage as CIImageRef ) as ImageRef
+  CIImageRepRef rep = fn CIImageRepWithCIImage( ciImage )
+  CGSize       size = fn ImageRepSize( rep )
+  ImageRef    image = fn ImageWithSize( size )
+  ImageAddRepresentation( image, rep )
+end fn = image
+
+local fn ColorWheelImage( colorSpace as CGColorSpaceRef, dither as CFNumberRef, radius as CFNumberRef, softness as CFNumberRef, lightness as CFNumberRef ) as CIImageRef
+  CIFilterRef filter = fn CIFilterWithName( @"CIHueSaturationValueGradient" )
+  ObjectSetValueForkey( filter, colorSpace, @"inputColorSpace" )
+  ObjectSetValueForkey( filter, dither,     @"inputDither"     )
+  ObjectSetValueForkey( filter, radius,     @"inputRadius"     )
+  ObjectSetValueForkey( filter, softness,   @"inputSoftness"   )
+  ObjectSetValueForkey( filter, lightness,  @"inputValue"      )
+  CIImageRef outputCIImage = fn CIFilterOutputImage( filter )
+end fn = outputCIImage
+
+local fn BuildColorWheel
+  CIImageRef colorWheelCIImage = fn ColorWheelImage( fn CGColorSpaceCreateDeviceRGB, @0, @160, @0, @1 )
+  ImageRef   colorWheelImage   = fn CIImageToImageRef( colorWheelCIImage )
+  ImageViewSetImage( _colorwheelImageView, colorWheelImage )
+end fn
+
+fn BuildWindow
+fn BuildColorWheel
+
+HandleEvents
--- a/Task/Color-wheel/GML/color-wheel.gml
+++ b/Task/Color-wheel/GML/color-wheel.gml
@ -0,0 +1,20 @@
+for (var i = 1; i <= 360; i++) {
+    for (var j = 0; j < 255; j++) {
+
+        var hue = 255*(i/360);
+        var saturation = j;
+        var value = 255;
+
+        var c = make_colour_hsv(hue,saturation,value);
+
+        //size of circle determined by how far from the center it is
+        //if you just draw them too small the circle won't be full.
+        //it will have patches inside it that didn't get filled in with color
+        var r = max(1,3*(j/255));
+
+        //Math for built-in GMS functions
+        //lengthdir_x(len,dir) = +cos(degtorad(direction))*length;
+        //lengthdir_y(len,dir) = -sin(degtorad(direction))*length;
+        draw_circle_colour(x+lengthdir_x(m_radius*(j/255),i),y+lengthdir_y(m_radius*(j/255),i),r,c,c,false);
+    }
+}
--- a/Task/Color-wheel/Go/color-wheel.go
+++ b/Task/Color-wheel/Go/color-wheel.go
@ -0,0 +1,68 @@
+package main
+
+import (
+    "github.com/fogleman/gg"
+    "math"
+)
+
+const tau = 2 * math.Pi
+
+func hsb2rgb(hue, sat, bri float64) (r, g, b int) {
+    u := int(bri*255 + 0.5)
+    if sat == 0 {
+        r, g, b = u, u, u
+    } else {
+        h := (hue - math.Floor(hue)) * 6
+        f := h - math.Floor(h)
+        p := int(bri*(1-sat)*255 + 0.5)
+        q := int(bri*(1-sat*f)*255 + 0.5)
+        t := int(bri*(1-sat*(1-f))*255 + 0.5)
+        switch int(h) {
+        case 0:
+            r, g, b = u, t, p
+        case 1:
+            r, g, b = q, u, p
+        case 2:
+            r, g, b = p, u, t
+        case 3:
+            r, g, b = p, q, u
+        case 4:
+            r, g, b = t, p, u
+        case 5:
+            r, g, b = u, p, q
+        }
+    }
+    return
+}
+
+func colorWheel(dc *gg.Context) {
+    width, height := dc.Width(), dc.Height()
+    centerX, centerY := width/2, height/2
+    radius := centerX
+    if centerY < radius {
+        radius = centerY
+    }
+    for y := 0; y < height; y++ {
+        dy := float64(y - centerY)
+        for x := 0; x < width; x++ {
+            dx := float64(x - centerX)
+            dist := math.Sqrt(dx*dx + dy*dy)
+            if dist <= float64(radius) {
+                theta := math.Atan2(dy, dx)
+                hue := (theta + math.Pi) / tau
+                r, g, b := hsb2rgb(hue, 1, 1)
+                dc.SetRGB255(r, g, b)
+                dc.SetPixel(x, y)
+            }
+        }
+    }
+}
+
+func main() {
+    const width, height = 480, 480
+    dc := gg.NewContext(width, height)
+    dc.SetRGB(1, 1, 1) // set background color to white
+    dc.Clear()
+    colorWheel(dc)
+    dc.SavePNG("color_wheel.png")
+}
--- a/Task/Color-wheel/J/color-wheel.j
+++ b/Task/Color-wheel/J/color-wheel.j
@ -0,0 +1,6 @@
+rgbc=: {{1-x*0>.1<.(<.4&-)6|m+y%60}}
+hsv=: 5 rgbc(,"0 1) 3 rgbc(,"0) 1 rgbc
+degrees=: {{180p_1*{:"1+.^.y}}
+wheel=: {{((1>:|)*|hsv degrees)j./~y%~i:y}}
+require'viewmat'
+'rgb' viewmat 256#.<.255*wheel 400
--- a/Task/Color-wheel/Java/color-wheel.java
+++ b/Task/Color-wheel/Java/color-wheel.java
@ -0,0 +1,80 @@
+import java.awt.*;
+import javax.swing.*;
+
+public class ColorWheel {
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(new Runnable() {
+            public void run() {
+                ColorWheelFrame frame = new ColorWheelFrame();
+                frame.setVisible(true);
+            }
+        });
+    }
+
+    private static class ColorWheelFrame extends JFrame {
+        private ColorWheelFrame() {
+            super("Color Wheel");
+            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+            getContentPane().add(new ColorWheelPanel());
+            pack();
+        }
+    }
+
+    private static class ColorWheelPanel extends JComponent {
+        private ColorWheelPanel() {
+            setPreferredSize(new Dimension(400, 400));
+        }
+        public void paint(Graphics g) {
+            Graphics2D g2 = (Graphics2D)g;
+            int w = getWidth();
+            int h = getHeight();
+            int margin = 10;
+            int radius = (Math.min(w, h) - 2 * margin)/2;
+            int cx = w/2;
+            int cy = h/2;
+            float[] dist = {0.F, 1.0F};
+            g2.setColor(Color.BLACK);
+            g2.fillRect(0, 0, w, h);
+            for (int angle = 0; angle < 360; ++angle) {
+                Color color = hsvToRgb(angle, 1.0, 1.0);
+                Color[] colors = {Color.WHITE, color};
+                RadialGradientPaint paint = new RadialGradientPaint(cx, cy,
+                        radius, dist, colors);
+                g2.setPaint(paint);
+                g2.fillArc(cx - radius, cy - radius, radius*2, radius*2,
+                        angle, 1);
+            }
+        }
+    }
+
+    private static Color hsvToRgb(int h, double s, double v) {
+        double hp = h/60.0;
+        double c = s * v;
+        double x = c * (1 - Math.abs(hp % 2.0 - 1));
+        double m = v - c;
+        double r = 0, g = 0, b = 0;
+        if (hp <= 1) {
+            r = c;
+            g = x;
+        } else if (hp <= 2) {
+            r = x;
+            g = c;
+        } else if (hp <= 3) {
+            g = c;
+            b = x;
+        } else if (hp <= 4) {
+            g = x;
+            b = c;
+        } else if (hp <= 5) {
+            r = x;
+            b = c;
+        } else {
+            r = c;
+            b = x;
+        }
+        r += m;
+        g += m;
+        b += m;
+        return new Color((int)(r * 255), (int)(g * 255), (int)(b * 255));
+    }
+}
--- a/Task/Color-wheel/Julia/color-wheel.julia
+++ b/Task/Color-wheel/Julia/color-wheel.julia
@ -0,0 +1,26 @@
+using Gtk, Graphics, Colors
+
+const win = GtkWindow("Color Wheel", 450, 450) |> (const can = @GtkCanvas())
+set_gtk_property!(can, :expand, true)
+
+@guarded draw(can) do widget
+    ctx = getgc(can)
+    h = height(can)
+    w = width(can)
+    center = (x = w / 2, y = h / 2)
+    anglestep = 1/w
+    for θ in 0:0.1:360
+        rgb = RGB(HSV(θ, 1, 1))
+        set_source_rgb(ctx, rgb.r, rgb.g, rgb.b)
+        line_to(ctx, center...)
+        arc(ctx, center.x, center.y, w/2.2, 2π * θ / 360, anglestep)
+        line_to(ctx, center...)
+        stroke(ctx)
+    end
+end
+
+show(can)
+const condition = Condition()
+endit(w) = notify(condition)
+signal_connect(endit, win, :destroy)
+wait(condition)
--- a/Task/Color-wheel/Kotlin/color-wheel.kotlin
+++ b/Task/Color-wheel/Kotlin/color-wheel.kotlin
@ -0,0 +1,51 @@
+// Version 1.2.41
+
+import java.awt.Color
+import java.awt.Graphics
+import java.awt.image.BufferedImage
+import java.io.File
+import javax.imageio.ImageIO
+import kotlin.math.*
+
+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 colorWheel() {
+        val centerX = image.width / 2
+        val centerY = image.height / 2
+        val radius = minOf(centerX, centerY)
+        for (y in 0 until image.height) {
+            val dy = (y - centerY).toDouble()
+            for (x in 0 until image.width) {
+                val dx = (x - centerX).toDouble()
+                val dist = sqrt(dx * dx + dy * dy)
+                if (dist <= radius) {
+                    val theta = atan2(dy, dx)
+                    val hue = (theta + PI) / (2.0 * PI)
+                    val rgb = Color.HSBtoRGB(hue.toFloat(), 1.0f, 1.0f)
+                    setPixel(x, y, Color(rgb))
+                }
+            }
+        }
+    }
+}
+
+fun main(args: Array<String>) {
+    val bbs = BasicBitmapStorage(480, 480)
+    with (bbs) {
+        fill(Color.white)
+        colorWheel()
+        val cwFile = File("Color_wheel.png")
+        ImageIO.write(image, "png", cwFile)
+    }
+}
--- a/Task/Color-wheel/Lua/color-wheel.lua
+++ b/Task/Color-wheel/Lua/color-wheel.lua
@ -0,0 +1,33 @@
+local function hsv_to_rgb (h, s, v)  -- values in ranges: [0, 360], [0, 1], [0, 1]
+    local r = math.min (math.max (3*math.abs (((h       )/180)%2-1)-1, 0), 1)
+    local g = math.min (math.max (3*math.abs (((h   -120)/180)%2-1)-1, 0), 1)
+    local b = math.min (math.max (3*math.abs (((h   +120)/180)%2-1)-1, 0), 1)
+    local k1 = v*(1-s)
+    local k2 = v - k1
+    return k1+k2*r, k1+k2*g, k1+k2*b -- values in ranges: [0, 1], [0, 1], [0, 1]
+end
+
+function love.load()
+    local w, h, r = 256, 256, 128-0.5
+    local cx, cy = w/2, h/2
+    canvas = love.graphics.newCanvas ()
+    love.graphics.setCanvas(canvas)
+        for x = 0, w do
+            for y = 0, h do
+                local dx, dy = x-cx, y-cy
+                if dx*dx + dy*dy <= r*r then
+                    local h = math.deg(math.atan2(dy, dx))
+                    local s = (dx*dx + dy*dy)^0.5/r
+                    local v = 1
+                    love.graphics.setColor (hsv_to_rgb (h, s, v))
+                    love.graphics.points (x, y)
+                end
+            end
+        end
+    love.graphics.setCanvas()
+end
+
+function love.draw()
+    love.graphics.setColor (1,1,1)
+    love.graphics.draw (canvas)
+end
--- a/Task/Color-wheel/M2000-Interpreter/color-wheel.m2000
+++ b/Task/Color-wheel/M2000-Interpreter/color-wheel.m2000
@ -0,0 +1,79 @@
+Module Check {
+      \\ we use an internal object for Math functions (here for Atan2)
+      Declare Math Math
+      Const tau=2*Pi, Center=2
+      \\ change console size,  and center it ( using ;) to current monitor
+      Window 12, 800*twipsX,600*twipsY;
+      \\ actual size maybe less (so can fit text exactly)
+      Double  ' Double height characters
+      Report Center, "Color wheel"
+      Normal  ' restore to normal
+      Atan2=Lambda Math (a, b) ->{
+            Method Math, "Atan2", a, b As ret
+            =ret
+      }
+      \\ brightness=1 for this program
+      hsb2rgb=Lambda (hue, sat) ->{
+            If sat == 0 Then {
+                = 255, 255, 255
+           } Else {
+                  h=frac(hue+1)*6
+                  f = frac(h)
+                  p = Int((1-sat)*255 + 0.5)
+                  q = Int((1-sat*f)*255 + 0.5)
+                  t = Int((1-sat*(1-f))*255 + 0.5)
+                  Select Case Int(h)
+                  Case 1
+                      = q, 255, p
+                  Case 2
+                      = p, 255, t
+                  Case 3
+                     = p, q, 255
+                  Case 4
+                      = t, p, 255
+                  Case 5
+                      = 255, p, q
+                  Else Case
+                      = 255, t, p
+                  End Select
+          }
+      }
+      Let OffsetX=X.twips/2-128*TwipsX, OffsetY=Y.twips/2-128*TwipsY
+      \\ a pixel has a size of TwipsX x TwipsY
+      OffsetX=(OffsetX div TwipsX)*TwipsX
+      OffsetY=(OffsetY div TwipsY)*TwipsY
+      \\ We set hsb2rgb, OffsetX, OffsetY as closures to PrintPixel
+      \\ We send to stack the R G B values using Stack ! array
+      \\ hsb2rgb() return an array of values
+      \\ we pop these values using Number
+      PrintPixel = Lambda  hsb2rgb, OffsetX, OffsetY (x,y, theta, sat)  -> {
+            Stack ! hsb2rgb(theta,sat)
+            PSet Color(number, number, number), x*TwipsX+offsetX, y*TwipsY+offsetY
+      }
+      \\ set Atan2, tau as closures to HueCircle
+      \\ we can rotate/flip the wheel by changing signs in Atan2() and
+      \\ by changing order of arguments (dx,dy) or (dy,dx). 8 combinations
+      HueCircle= Lambda Atan2, tau (PrintPixel) -> {
+            Let  c_width=256, c_height=256
+            Let  cx=c_width/2, cy=c_height/2
+            Let  radius=If(cx<=cy->cx, cy)
+            c_width--
+            c_height--
+            dy=-cy
+            For y=0 To c_height {
+                  dy++ : dy2=dy*dy : dx=-cx
+                  For x=0 To c_width {
+                        dx++ : dist=Sqrt(dx^2+dy2)
+                        If dist>radius Then continue
+                        Call PrintPixel(x,y, Atan2(dx, -dy)/tau, dist/radius)
+                  }
+            }
+      }
+      Call HueCircle(PrintPixel)
+      Scr$=""  ' we use this string  to load an image
+      Move 0,0
+      \\ scale.x, scale.y are twips height and width, of current layer
+      Copy scale.x, scale.y to Scr$
+      Clipboard Scr$  ' save window to clipboard
+}
+Check
--- a/Task/Color-wheel/Mathematica/color-wheel.math
+++ b/Task/Color-wheel/Mathematica/color-wheel.math
@ -0,0 +1,9 @@
+r = 100;
+Image[Table[
+  If[x^2 + y^2 <= r^2,
+   angle = Mod[ArcTan[N@x, y]/(2 Pi), 1];
+   List @@ RGBColor[Hue[angle, Sqrt[x^2 + y^2]/N[r], 1.0]]
+   ,
+   {1, 1, 1}
+   ], {x, -r, r}, {y, -r, r}]
+ ]
--- a/Task/Color-wheel/Nim/color-wheel.nim
+++ b/Task/Color-wheel/Nim/color-wheel.nim
@ -0,0 +1,67 @@
+import math
+
+import imageman
+
+#---------------------------------------------------------------------------------------------------
+
+func hsvToRgb(h, s, v: float): ColorRGBU =
+  ## Convert HSV values to RGB values.
+
+  let hp = h / 60
+  let c = s * v
+  let x = c * (1 - abs(hp mod 2 - 1))
+  let m = v - c
+  var r, g, b = 0.0
+  if hp <= 1:
+    r = c
+    g = x
+  elif hp <= 2:
+    r = x
+    g = c
+  elif hp <= 3:
+    g = c
+    b = x
+  elif hp <= 4:
+    g = x
+    b= c
+  elif hp <= 5:
+    r = x
+    b = c
+  else:
+    r = c
+    b = x
+  r += m
+  g += m
+  b += m
+  result = ColorRGBU [byte(r * 255), byte(g * 255), byte(b * 255)]
+
+#---------------------------------------------------------------------------------------------------
+
+func buildColorWheel(image: var Image) =
+  ## Build a color wheel into the image.
+
+  const Margin = 10
+  let diameter = min(image.w, image.h) - 2 * Margin
+  let xOffset = (image.w - diameter) div 2
+  let yOffset = (image.h - diameter) div 2
+  let radius = diameter / 2
+
+  for x in 0..diameter:
+    let rx = x.toFloat - radius
+    for y in 0..diameter:
+      let ry = y.toFloat - radius
+      let r = hypot(rx, ry) / radius
+      if r > 1: continue
+      let a = 180 + arctan2(ry, -rx).radToDeg()
+      image[x + xOffset, y + yOffset] = hsvToRgb(a, r, 1)
+
+#———————————————————————————————————————————————————————————————————————————————————————————————————
+
+const
+  Side = 400
+  Output = "color_wheel.png"
+
+var image = initImage[ColorRGBU](Side, Side)
+image.buildColorWheel()
+
+image.savePNG(Output, compression = 9)
--- a/Task/Color-wheel/Perl/color-wheel.pl
+++ b/Task/Color-wheel/Perl/color-wheel.pl
@ -0,0 +1,22 @@
+use Imager;
+use Math::Complex qw(cplx i pi);
+
+my ($width, $height) = (300, 300);
+my $center = cplx($width/2, $height/2);
+
+my $img = Imager->new(xsize => $width,
+                      ysize => $height);
+
+foreach my $y (0 .. $height - 1) {
+    foreach my $x (0 .. $width - 1) {
+
+        my $vec = $center - $x - $y * i;
+        my $mag = 2 * abs($vec) / $width;
+        my $dir = (pi + atan2($vec->Re, $vec->Im)) / (2 * pi);
+
+        $img->setpixel(x => $x, y => $y,
+            color => {hsv => [360 * $dir, $mag, $mag < 1 ? 1 : 0]});
+    }
+}
+
+$img->write(file => 'color_wheel.png');
--- a/Task/Color-wheel/Phix/color-wheel.phix
+++ b/Task/Color-wheel/Phix/color-wheel.phix
@ -0,0 +1,60 @@
+(phixonline)-->
+ <span style="color: #000080;font-style:italic;">--
+ -- demo\rosetta\Colour_wheel.exw
+ -- =============================
+ --
+ --  Note: Made non-resizeable since maximising this is far too slow.
+ --</span>
+ <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
+ <span style="color: #008080;">include</span> <span style="color: #000000;">pGUI</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
+
+ <span style="color: #008080;">constant</span> <span style="color: #000000;">title</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"Colour wheel"</span>
+ <span style="color: #004080;">Ihandle</span> <span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">canvas</span>
+ <span style="color: #004080;">cdCanvas</span> <span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span>
+
+ <span style="color: #008080;">function</span> <span style="color: #000000;">redraw_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*ih*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000080;font-style:italic;">/*posx*/</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">/*posy*/</span><span style="color: #0000FF;">)</span>
+     <span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">w</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">h</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupGetIntInt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"DRAWSIZE"</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">cdCanvasActivate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
+     <span style="color: #004080;">integer</span> <span style="color: #000000;">radius</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">min</span><span style="color: #0000FF;">(</span><span style="color: #000000;">w</span><span style="color: #0000FF;">,</span><span style="color: #000000;">h</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
+     <span style="color: #004080;">integer</span> <span style="color: #000000;">cx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">w</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span>
+             <span style="color: #000000;">cy</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">h</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
+
+     <span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">w</span> <span style="color: #008080;">do</span>
+         <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">h</span> <span style="color: #008080;">do</span>
+             <span style="color: #004080;">integer</span> <span style="color: #000000;">rx</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">x</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">cx</span><span style="color: #0000FF;">,</span>
+                     <span style="color: #000000;">ry</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">y</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">cy</span>
+             <span style="color: #004080;">atom</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rx</span><span style="color: #0000FF;">*</span><span style="color: #000000;">rx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">ry</span><span style="color: #0000FF;">*</span><span style="color: #000000;">ry</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">/</span> <span style="color: #000000;">radius</span>
+             <span style="color: #008080;">if</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;"><=</span> <span style="color: #000000;">1.0</span> <span style="color: #008080;">then</span>
+                 <span style="color: #004080;">atom</span> <span style="color: #000000;">hue</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">((</span><span style="color: #7060A8;">atan2</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ry</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">rx</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">/</span> <span style="color: #004600;">PI</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">1.0</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">/</span> <span style="color: #000000;">2.0</span>
+                 <span style="color: #7060A8;">cdCanvasPixel</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">h</span><span style="color: #0000FF;">-</span><span style="color: #000000;">y</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">hsv_to_rgb</span><span style="color: #0000FF;">(</span><span style="color: #000000;">hue</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">))</span>
+             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+     <span style="color: #7060A8;">cdCanvasFlush</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+
+ <span style="color: #008080;">function</span> <span style="color: #000000;">map_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
+     <span style="color: #000000;">cdcanvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_IUP</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
+     <span style="color: #000000;">cddbuffer</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_DBUFFER</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">cdCanvasSetBackground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_WHITE</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">cdCanvasSetForeground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_MAGENTA</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+
+ <span style="color: #008080;">procedure</span> <span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
+     <span style="color: #7060A8;">IupOpen</span><span style="color: #0000FF;">()</span>
+     <span style="color: #000000;">canvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">NULL</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"RASTERSIZE"</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"300x300"</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"MAP_CB"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"map_cb"</span><span style="color: #0000FF;">))</span>
+     <span style="color: #000000;">dlg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupDialog</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span><span style="color: #008000;">`TITLE="%s",RESIZE=NO`</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">title</span><span style="color: #0000FF;">})</span>
+     <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"ACTION"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"redraw_cb"</span><span style="color: #0000FF;">))</span>
+     <span style="color: #7060A8;">IupShowXY</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span><span style="color: #004600;">IUP_CENTER</span><span style="color: #0000FF;">,</span><span style="color: #004600;">IUP_CENTER</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
+         <span style="color: #7060A8;">IupMainLoop</span><span style="color: #0000FF;">()</span>
+         <span style="color: #7060A8;">IupClose</span><span style="color: #0000FF;">()</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
+
+ <span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
+<!--
--- a/Task/Color-wheel/Processing-Python-mode/color-wheel.processing-py
+++ b/Task/Color-wheel/Processing-Python-mode/color-wheel.processing-py
@ -0,0 +1,14 @@
+size(300, 300)
+background(0)
+radius = min(width, height) / 2.0
+cx, cy = width / 2, width / 2
+for x in range(width):
+        for y in range(height):
+            rx = x - cx
+            ry = y - cy
+            s = sqrt(rx ** 2 + ry ** 2) / radius
+            if s <= 1.0:
+                h = ((atan2(ry, rx) / PI) + 1.0) / 2.0
+                colorMode(HSB)
+                c = color(int(h * 255), int(s * 255), 255)
+                set(x, y, c) # note set() used as Processing set() not as Python set()
--- a/Task/Color-wheel/Processing/color-wheel.processing
+++ b/Task/Color-wheel/Processing/color-wheel.processing
@ -0,0 +1,18 @@
+size(300, 300);
+background(0);
+float radius = min(width, height) / 2.0;
+float cx = width / 2;
+float cy = width / 2;
+for (int x = 0; x < width; x++) {
+  for (int y = 0; y < width; y++) {
+    float rx = x - cx;
+    float ry = y - cy;
+    float s = sqrt(sq(rx) + sq(ry)) / radius;
+    if (s <= 1.0) {
+      float h = ((atan2(ry, rx) / PI) + 1.0) / 2.0;
+      colorMode(HSB);
+      color c = color(int(h * 255), int(s * 255), 255);
+      set(x, y, c);
+    }
+  }
+}
--- a/Task/Color-wheel/Python/color-wheel.py
+++ b/Task/Color-wheel/Python/color-wheel.py
@ -0,0 +1,22 @@
+from PIL import Image
+import colorsys
+import math
+
+if __name__ == "__main__":
+
+    im = Image.new("RGB", (300,300))
+    radius = min(im.size)/2.0
+    cx, cy = im.size[0]/2, im.size[1]/2
+    pix = im.load()
+
+    for x in range(im.width):
+        for y in range(im.height):
+            rx = x - cx
+            ry = y - cy
+            s = (rx ** 2.0 + ry ** 2.0) ** 0.5 / radius
+            if s <= 1.0:
+                h = ((math.atan2(ry, rx) / math.pi) + 1.0) / 2.0
+                rgb = colorsys.hsv_to_rgb(h, s, 1.0)
+                pix[x,y] = tuple([int(round(c*255.0)) for c in rgb])
+
+    im.show()
--- a/Task/Color-wheel/Racket/color-wheel.rkt
+++ b/Task/Color-wheel/Racket/color-wheel.rkt
@ -0,0 +1,24 @@
+#lang racket
+
+(require racket/draw
+         colors)
+
+(define DIM 500)
+(define target (make-bitmap DIM DIM))
+(define dc (new bitmap-dc% [bitmap target]))
+(define radius 200)
+(define center (/ DIM 2))
+
+(define (atan2 y x) (if (= 0 y x) 0 (atan y x)))
+
+(for* ([x (in-range DIM)]
+       [y (in-range DIM)]
+       [rx (in-value (- x center))]
+       [ry (in-value (- y center))]
+       [s (in-value (/ (sqrt (+ (sqr rx) (sqr ry))) radius))]
+       #:when (<= s 1))
+  (define h (* 0.5 (+ 1 (/ (atan2 ry rx) pi))))
+  (send dc set-pen (hsv->color (hsv (if (= 1 h) 0 h) s 1)) 1 'solid)
+  (send dc draw-point x y))
+
+target
--- a/Task/Color-wheel/Raku/color-wheel.raku
+++ b/Task/Color-wheel/Raku/color-wheel.raku
@ -0,0 +1,36 @@
+use Image::PNG::Portable;
+
+my ($w, $h) = 300, 300;
+
+my $out = Image::PNG::Portable.new: :width($w), :height($h);
+
+my $center = $w/2 + $h/2*i;
+
+color-wheel($out);
+
+$out.write: 'Color-wheel-perl6.png';
+
+sub color-wheel ( $png ) {
+    ^$w .race.map: -> $x {
+        for ^$h -> $y {
+            my $vector    = $center - $x - $y*i;
+            my $magnitude = $vector.abs * 2 / $w;
+            my $direction = ( π + atan2( |$vector.reals ) ) / τ;
+            $png.set: $x, $y, |hsv2rgb( $direction, $magnitude, $magnitude < 1 );
+        }
+    }
+}
+
+sub hsv2rgb ( $h, $s, $v ){
+    my $c = $v * $s;
+    my $x = $c * (1 - abs( (($h*6) % 2) - 1 ) );
+    my $m = $v - $c;
+    (do given $h {
+        when   0..^1/6 { $c, $x, 0 }
+        when 1/6..^1/3 { $x, $c, 0 }
+        when 1/3..^1/2 { 0, $c, $x }
+        when 1/2..^2/3 { 0, $x, $c }
+        when 2/3..^5/6 { $x, 0, $c }
+        when 5/6..1    { $c, 0, $x }
+    } ).map: ((*+$m) * 255).Int
+}
--- a/Task/Color-wheel/Ring/color-wheel.ring
+++ b/Task/Color-wheel/Ring/color-wheel.ring
@ -0,0 +1,92 @@
+#===================================================================#
+#  Sample: Color Wheel
+#  Author: Gal Zsolt, Bert Mariani, Ilir Liburn & Mahmoud Fayed
+#===================================================================#
+
+load "guilib.ring"
+
+xWidth  = 400
+yHeight = 400
+
+MyApp = new qapp
+{
+   win1 = new qwidget()
+   {  setwindowtitle("ColorWheel-FastDraw")
+      setgeometry(500,150,xWidth,yHeight)
+
+      Canvas = new qlabel(win1)
+      {  ### daVinci paints the MonaLisa on the Canvas
+         MonaLisa  = new qPixMap2( xWidth, yHeight)
+             color = new qcolor(){ setrgb(255,255,255,0) }
+              pen  = new qpen()  { setwidth(1) }
+         MonaLisa.fill(color)
+
+         daVinci = new qpainter()
+         {  begin(MonaLisa)
+            #endpaint()           ### This will Stop the Painting. For Animation comment it out
+         }
+
+         setPixMap(MonaLisa)
+      }
+
+      show()
+   }
+
+   ColorWheel()
+   exec()
+}
+
+//=====================
+
+Func colorWheel
+
+   #=====================================================================#
+   ? "Start Processing..."
+   t1 = clock()
+   ? "Clock : " + t1
+   #=====================================================================#
+
+   aList = []
+   pi       = 3.14159265359
+   diameter = pi * 2
+   radius   = yHeight / 2
+   v        = 1                    // value/brightness  1 to 100  1=bright 0=dark
+
+   for i = 1 to xWidth
+      iradius = i - radius
+            p = pow( iradius, 2)
+
+      for j = 1 to yHeight
+
+          h = (atan2( iradius, j-radius ) + pi ) / diameter   // hue/color  1 to 360
+          s =   sqrt( p + pow( j-radius, 2)) / radius         // saturation/intensity 1 to 100
+
+         if s <= 1 and h <= 1
+            aList + [i,j,h,s,v,1]
+         ok
+
+      next
+   next
+
+   #=====================================================================#
+   ? "Start drawing..."
+   t2 = clock()
+   ? "Clock : " + t2
+   #=====================================================================#
+
+   daVinci.drawHSVFList(aList)
+   Canvas.setPixMap(MonaLisa)
+
+   #=====================================================================#
+   ? "Done..."
+   t3 = clock()
+   ? "Clock : " + t3
+   #=====================================================================#
+   ? "Processing Time: " + ( (t2-t1)/ClocksPerSecond() ) + " seconds "
+   ? "Drawing Time: " + ( (t3-t2)/ClocksPerSecond() ) + " seconds "
+   ? "Total Time: " + ( (t3-t1)/ClocksPerSecond() ) + " seconds "
+   #=====================================================================#
+
+ return
+
+//==================
--- a/Task/Color-wheel/Ruby/color-wheel.rb
+++ b/Task/Color-wheel/Ruby/color-wheel.rb
@ -0,0 +1,21 @@
+def settings
+  size(300, 300)
+end
+
+def setup
+  sketch_title 'Color Wheel'
+  background(0)
+  radius = width / 2.0
+  center = width / 2
+  grid(width, height) do |x, y|
+    rx = x - center
+    ry = y - center
+    sat = Math.hypot(rx, ry) / radius
+    if sat <= 1.0
+      hue = ((Math.atan2(ry, rx) / PI) + 1) / 2.0
+      color_mode(HSB)
+      col = color((hue * 255).to_i, (sat * 255).to_i, 255)
+      set(x, y, col)
+    end
+  end
+end
--- a/Task/Color-wheel/Run-BASIC/color-wheel.basic
+++ b/Task/Color-wheel/Run-BASIC/color-wheel.basic
@ -0,0 +1,66 @@
+' -----------------------------------
+' color wheel
+' -----------------------------------
+global pi
+pi  = 22 / 7
+steps   = 1
+
+graphic #g, 525, 525
+
+
+for x =0 to 525 step steps
+    for y =0 to 525 step steps
+        angle   = atan2(y - 250, x - 250) * 360 / 2 / pi      '  full degrees....
+        sector  = int(angle / 60)                             '    60 degree sectors (0 to 5)
+        slope   = (angle mod 60) /60 * 255                    '     1 degree sectors.
+
+        if  sector = 0 then  col$    = "255 ";                    str$( int( slope));      "   0"
+        if  sector = 1 then  col$    = str$(int(256 - slope)); " 255                          0"
+        if  sector = 2 then  col$    = "0                         255 ";                     str$( int( slope))
+        if  sector = 3 then  col$    = "0 ";                      str$( int( 256 -slope)); " 255"
+        if  sector = 4 then  col$    = str$(int(slope));    "     0                        255"
+        if  sector = 5 then  col$    = "255                         0 ";                     str$( int( 256 -slope))
+
+        red = val( word$( col$, 1))
+        grn = val( word$( col$, 2))
+        blu = val( word$( col$, 3))
+        p   = ((x -270)^2 +(y -270)^2)^0.5 / 250
+        r   = min(255,p * red)
+        g   = min(255,p * grn)
+        b   = min(255,p * blu)
+        if p > 1 then  #g "color white" else #g color(r,g,b)
+        #g "set "; x; " "; y
+    next y
+next x
+render #g
+end
+
+function atan2(y,x)
+if (x = 0) and (y <> 0) then
+    r$ = "Y"
+    if y > 0 then atan2 = pi /2
+    if y < 0 then atan2 = 3 * pi /2
+end if
+
+if y = 0 and (x <> 0) then
+    r$ = "Y"
+    if x > 0 then atan2 = 0
+    if x < 0 then atan2 = pi
+end if
+
+If r$ <> "Y" then
+    if x = 0 and y = 0 then
+        atan2   = 0
+        else
+        baseAngle = atn(abs(y) / abs(x))
+        if x > 0 then
+            if y > 0 then atan2 = baseAngle
+            If y < 0 then atan2 = 2 * pi - baseAngle
+        end if
+        if x < 0 then
+            If y > 0 then atan2 = pi - baseAngle
+            If y < 0 then atan2 = pi + baseAngle
+        end if
+    end if
+end if
+end function
--- a/Task/Color-wheel/Rust/color-wheel.rust
+++ b/Task/Color-wheel/Rust/color-wheel.rust
@ -0,0 +1,67 @@
+// [dependencies]
+// image = "0.23"
+
+use image::error::ImageResult;
+use image::{Rgb, RgbImage};
+
+fn hsv_to_rgb(h: f64, s: f64, v: f64) -> Rgb<u8> {
+    let hp = h / 60.0;
+    let c = s * v;
+    let x = c * (1.0 - (hp % 2.0 - 1.0).abs());
+    let m = v - c;
+    let mut r = 0.0;
+    let mut g = 0.0;
+    let mut b = 0.0;
+    if hp <= 1.0 {
+        r = c;
+        g = x;
+    } else if hp <= 2.0 {
+        r = x;
+        g = c;
+    } else if hp <= 3.0 {
+        g = c;
+        b = x;
+    } else if hp <= 4.0 {
+        g = x;
+        b = c;
+    } else if hp <= 5.0 {
+        r = x;
+        b = c;
+    } else {
+        r = c;
+        b = x;
+    }
+    r += m;
+    g += m;
+    b += m;
+    Rgb([(r * 255.0) as u8, (g * 255.0) as u8, (b * 255.0) as u8])
+}
+
+fn write_color_wheel(filename: &str, width: u32, height: u32) -> ImageResult<()> {
+    let mut image = RgbImage::new(width, height);
+    let margin = 10;
+    let diameter = std::cmp::min(width, height) - 2 * margin;
+    let xoffset = (width - diameter) / 2;
+    let yoffset = (height - diameter) / 2;
+    let radius = diameter as f64 / 2.0;
+    for x in 0..=diameter {
+        let rx = x as f64 - radius;
+        for y in 0..=diameter {
+            let ry = y as f64 - radius;
+            let r = ry.hypot(rx) / radius;
+            if r > 1.0 {
+                continue;
+            }
+            let a = 180.0 + ry.atan2(-rx).to_degrees();
+            image.put_pixel(x + xoffset, y + yoffset, hsv_to_rgb(a, r, 1.0));
+        }
+    }
+    image.save(filename)
+}
+
+fn main() {
+    match write_color_wheel("color_wheel.png", 400, 400) {
+        Ok(()) => {}
+        Err(error) => eprintln!("{}", error),
+    }
+}
--- a/Task/Color-wheel/Sidef/color-wheel.sidef
+++ b/Task/Color-wheel/Sidef/color-wheel.sidef
@ -0,0 +1,17 @@
+require('Imager')
+
+var (width, height) = (300, 300)
+var center = Complex(width/2 , height/2)
+
+var img = %O<Imager>.new(xsize => width, ysize => height)
+
+for y=(^height), x=(^width) {
+    var vector    = (center - x - y.i)
+    var magnitude = (vector.abs * 2 / width)
+    var direction = ((Num.pi + atan2(vector.real, vector.imag)) / Num.tau)
+    img.setpixel(x => x, y => y,
+        color => Hash(hsv => [360*direction, magnitude, magnitude < 1 ? 1 : 0])
+    )
+}
+
+img.write(file => 'color_wheel.png')
--- a/Task/Color-wheel/Smart-BASIC/color-wheel.basic
+++ b/Task/Color-wheel/Smart-BASIC/color-wheel.basic
@ -0,0 +1,46 @@
+' Runs on iOS
+GET SCREEN SIZE sw,sh
+xmax=0.45*3/7*(sw+sh)
+x0=sw/2!y0=sh/2
+twopi=2*3.1415926
+GRAPHICS
+GRAPHICS CLEAR
+DIM triX(1000), triY(1000)
+triX(0)=x0 ! triY(0)=y0
+steps=INT(1^2*360)+1
+dAngle=twopi/steps
+dAngle2=dAngle/2
+REFRESH OFF
+FOR i=0 TO steps-1
+  pal(i/steps+TintOffset)
+  ANGLE=i*dAngle
+  FILL COLOR pal.r,pal.g,pal.b
+  DRAW COLOR pal.r,pal.g,pal.b
+  x=x0+(xmax-radius)*COS(ANGLE)
+  y=y0-(xmax-radius)*SIN(ANGLE)
+  k=0
+  FOR j=-dAngle2 TO dAngle2 STEP 0.02
+    k+=1
+    triX(k)=x0+xmax*COS(ANGLE+j)
+    triY(k)=y0-xmax*SIN(ANGLE+j)
+  NEXT j
+  k+=1
+  triX(k)=x0+xmax*COS(ANGLE+dAngle2)
+  triY(k)=y0-xmax*SIN(ANGLE+dAngle2)
+  DRAW POLY triX,triY COUNT k+1
+  FILL POLY triX,triY COUNT k+1
+NEXT i
+REFRESH ON
+END
+
+DEF pal(tint)
+tint=tint*360
+h=(tint%360)/60 ! f=FRACT(h) ! z=1-f ! ic=FLOOR(h)+1
+ON ic GOTO s1,s2,s3,s4,s5,s6
+  s1: r=1 ! g=f ! b=0 ! GOTO done
+  s2: r=z ! g=1 ! b=0 ! GOTO done
+  s3: r=0 ! g=1 ! b=f ! GOTO done
+  s4: r=0 ! g=z ! b=1 ! GOTO done
+  s5: r=f ! g=0 ! b=1 ! GOTO done
+  s6: r=1 ! g=0 ! b=z ! done:
+END DEF
--- a/Task/Color-wheel/VBScript/color-wheel.vb
+++ b/Task/Color-wheel/VBScript/color-wheel.vb
@ -0,0 +1,277 @@
+Option explicit
+
+Class ImgClass
+  Private ImgL,ImgH,ImgDepth,bkclr,loc,tt
+  private xmini,xmaxi,ymini,ymaxi,dirx,diry
+  public ImgArray()  'rgb in 24 bit mode, indexes to palette in 8 bits
+  private filename
+  private Palette,szpal
+
+  public property get xmin():xmin=xmini:end property
+  public property get ymin():ymin=ymini:end property
+  public property get xmax():xmax=xmaxi:end property
+  public property get ymax():ymax=ymaxi:end property
+  public property let depth(x)
+  if x<>8 and x<>32 then err.raise 9
+  Imgdepth=x
+  end property
+
+  public sub set0 (x0,y0) 'sets the new origin (default tlc). The origin does'nt work if ImgArray is accessed directly
+    if x0<0 or x0>=imgl or y0<0 or y0>imgh then err.raise 9
+    xmini=-x0
+    ymini=-y0
+    xmaxi=xmini+imgl-1
+    ymaxi=ymini+imgh-1
+  end sub
+
+  'constructor
+  Public Default Function Init(name,w,h,orient,dep,bkg,mipal)
+  'offx, offy posicion de 0,0. si ofx+ , x se incrementa de izq a der, si offy+ y se incrementa de abajo arriba
+  dim i,j
+  ImgL=w
+  ImgH=h
+  tt=timer
+  loc=getlocale
+  ' not useful as we are not using SetPixel and accessing  ImgArray directly
+  set0 0,0   'origin blc positive up and right
+  redim imgArray(ImgL-1,ImgH-1)
+  bkclr=bkg
+  if bkg<>0 then
+    for i=0 to ImgL-1
+      for j=0 to ImgH-1
+        imgarray(i,j)=bkg
+      next
+    next
+  end if
+  Select Case orient
+    Case 1: dirx=1 : diry=1
+    Case 2: dirx=-1 : diry=1
+    Case 3: dirx=-1 : diry=-1
+    Case 4: dirx=1 : diry=-1
+  End select
+  filename=name
+  ImgDepth =dep
+  'load user palette if provided
+  if imgdepth=8 then
+    loadpal(mipal)
+  end if
+  set init=me
+  end function
+
+  private sub loadpal(mipale)
+    if isarray(mipale) Then
+      palette=mipale
+      szpal=UBound(mipale)+1
+    Else
+      szpal=256
+    'Default palette recycled from ATARI
+    'removed
+
+, not relevant
+   End if
+  End Sub
+
+
+  'class termination writes it to a BMP file and displays it
+  'if an error happens VBS terminates the class before exiting so the BMP is displayed the same
+  Private Sub Class_Terminate
+
+    if err<>0 then wscript.echo "Error " & err.number
+    wscript.echo "copying image to bmp file"
+    savebmp
+    wscript.echo "opening " & filename & " with your default bmp viewer"
+    CreateObject("Shell.Application").ShellExecute filename
+    wscript.echo timer-tt & "  iseconds"
+  End Sub
+
+    function long2wstr( x)  'falta muy poco!!!
+      dim k1,k2,x1
+      k1=  (x and &hffff&)' or (&H8000& And ((X And &h8000&)<>0)))
+      k2=((X And &h7fffffff&) \ &h10000&) Or (&H8000& And (x<0))
+      long2wstr=chrw(k1) & chrw(k2)
+    end function
+
+    function int2wstr(x)
+        int2wstr=ChrW((x and &h7fff) or (&H8000 And (X<0)))
+    End Function
+
+
+   Public Sub SaveBMP
+    'Save the picture to a bmp file
+    Dim s,ostream, x,y,loc
+
+    const hdrs=54 '14+40
+    dim bms:bms=ImgH* 4*(((ImgL*imgdepth\8)+3)\4)  'bitmap size including padding
+    dim palsize:if (imgdepth=8) then palsize=szpal*4 else palsize=0
+
+    with  CreateObject("ADODB.Stream") 'auxiliary ostream, it creates an UNICODE with bom stream in memory
+      .Charset = "UTF-16LE"    'o "UTF16-BE"
+      .Type =  2' adTypeText
+      .open
+
+      'build a header
+      'bmp header: VBSCript does'nt have records nor writes binary values to files, so we use strings of unicode chars!!
+      'BMP header
+      .writetext ChrW(&h4d42)                           ' 0 "BM" 4d42
+      .writetext long2wstr(hdrs+palsize+bms)            ' 2 fiesize
+      .writetext long2wstr(0)                           ' 6  reserved
+      .writetext long2wstr (hdrs+palsize)               '10 image offset
+       'InfoHeader
+      .writetext long2wstr(40)                          '14 infoheader size
+      .writetext long2wstr(Imgl)                        '18 image length
+      .writetext long2wstr(imgh)                        '22 image width
+      .writetext int2wstr(1)                            '26 planes
+      .writetext int2wstr(imgdepth)                     '28 clr depth (bpp)
+      .writetext long2wstr(&H0)                         '30 compression used 0= NOCOMPR
+
+      .writetext long2wstr(bms)                         '34 imgsize
+      .writetext long2wstr(&Hc4e)                       '38 bpp hor
+      .writetext long2wstr(&hc43)                       '42 bpp vert
+      .writetext long2wstr(szpal)                       '46  colors in palette
+      .writetext long2wstr(&H0)                         '50 important clrs 0=all
+
+      'write bitmap
+      'precalc data for orientation
+       Dim x1,x2,y1,y2
+       If dirx=-1 Then x1=ImgL-1 :x2=0 Else x1=0:x2=ImgL-1
+       If diry=-1 Then y1=ImgH-1 :y2=0 Else y1=0:y2=ImgH-1
+
+      Select Case imgdepth
+
+      Case 32
+        For y=y1 To y2  step diry
+          For x=x1 To x2 Step dirx
+           'writelong fic, Pixel(x,y)
+           .writetext long2wstr(Imgarray(x,y))
+          Next
+        Next
+
+      Case 8
+        'palette
+        For x=0 to szpal-1
+          .writetext long2wstr(palette(x))  '52
+        Next
+        'image
+        dim pad:pad=ImgL mod 4
+        For y=y1 to y2 step diry
+          For x=x1 To x2 step dirx*2
+             .writetext chrw((ImgArray(x,y) and 255)+ &h100& *(ImgArray(x+dirx,y) and 255))
+          Next
+          'line padding
+          if pad and 1 then .writetext  chrw(ImgArray(x2,y))
+          if pad >1 then .writetext  chrw(0)
+         Next
+
+      Case Else
+        WScript.Echo "ColorDepth not supported : " & ImgDepth & " bits"
+      End Select
+
+      'use a second stream to save to file starting past the BOM  the first ADODB.Stream has added
+      Dim outf:Set outf= CreateObject("ADODB.Stream")
+      outf.Type    = 1 ' adTypeBinary
+      outf.Open
+      .position=2              'remove bom (1 wchar)
+      .CopyTo outf
+      .close
+      outf.savetofile filename,2   'adSaveCreateOverWrite
+      outf.close
+    end with
+  End Sub
+end class
+
+
+
+function hsv2rgb( Hue, Sat, Value) 'hue 0-360   0-ro 120-ver 240-az ,sat 0-100,value 0-100
+  dim Angle, Radius,Ur,Vr,Wr,Rdim
+  dim r,g,b, rgb
+  Angle = (Hue-150) *0.01745329251994329576923690768489
+  Ur = Value * 2.55
+  Radius = Ur * tan(Sat *0.01183199)
+  Vr = Radius * cos(Angle) *0.70710678  'sqrt(1/2)
+  Wr = Radius * sin(Angle) *0.40824829  'sqrt(1/6)
+  r = (Ur - Vr - Wr)
+  g = (Ur + Vr - Wr)
+  b = (Ur + Wr + Wr)
+
+  'clamp values
+ if r >255 then
+   Rdim = (Ur - 255) / (Vr + Wr)
+   r = 255
+   g = Ur + (Vr - Wr) * Rdim
+   b = Ur + 2 * Wr * Rdim
+ elseif r < 0 then
+   Rdim = Ur / (Vr + Wr)
+   r = 0
+   g = Ur + (Vr - Wr) * Rdim
+   b = Ur + 2 * Wr * Rdim
+ end if
+
+ if g >255 then
+   Rdim = (255 - Ur) / (Vr - Wr)
+   r = Ur - (Vr + Wr) * Rdim
+   g = 255
+   b = Ur + 2 * Wr * Rdim
+ elseif g<0 then
+   Rdim = -Ur / (Vr - Wr)
+   r = Ur - (Vr + Wr) * Rdim
+   g = 0
+   b = Ur + 2 * Wr * Rdim
+ end if
+ if b>255 then
+   Rdim = (255 - Ur) / (Wr + Wr)
+   r = Ur - (Vr + Wr) * Rdim
+   g = Ur + (Vr - Wr) * Rdim
+   b = 255
+ elseif b<0 then
+   Rdim = -Ur / (Wr + Wr)
+   r = Ur - (Vr + Wr) * Rdim
+   g = Ur + (Vr - Wr) * Rdim
+   b = 0
+ end If
+ 'b lowest byte, red highest byte
+ hsv2rgb= ((b and &hff)+256*((g and &hff)+256*(r and &hff))and &hffffff)
+end function
+
+function ang(col,row)
+    'if col =0 then  if row>0 then ang=0 else ang=180:exit function
+    if col =0 then
+      if row<0 then ang=90 else ang=270 end if
+    else
+   if col>0 then
+      ang=atn(-row/col)*57.2957795130
+   else
+     ang=(atn(row/-col)*57.2957795130)+180
+  end if
+  end if
+   ang=(ang+360) mod 360
+end function
+
+
+Dim X,row,col,fn,tt,hr,sat,row2
+const h=160
+const w=160
+const rad=159
+const r2=25500
+tt=timer
+fn=CreateObject("Scripting.FileSystemObject").GetSpecialFolder(2)& "\testwchr.bmp"
+Set X = (New ImgClass)(fn,w*2,h*2,1,32,0,0)
+
+x.set0 w,h
+'wscript.echo x.xmax, x.xmin
+
+for row=x.xmin+1 to x.xmax
+   row2=row*row
+   hr=int(Sqr(r2-row2))
+   For col=hr To 159
+     Dim a:a=((col\16 +row\16) And 1)* &hffffff
+     x.imgArray(col+160,row+160)=a
+     x.imgArray(-col+160,row+160)=a
+   next
+   for col=-hr to hr
+     sat=100-sqr(row2+col*col)/rad *50
+    ' wscript.echo c,r
+     x.imgArray(col+160,row+160)=hsv2rgb(ang(row,col)+90,100,sat)
+    next
+    'script.echo row
+  next
+Set X = Nothing
--- a/Task/Color-wheel/Vala/color-wheel.vala
+++ b/Task/Color-wheel/Vala/color-wheel.vala
@ -0,0 +1,36 @@
+public class Example: Gtk.Application {
+  private Gtk.ApplicationWindow window;
+  private Gtk.DrawingArea drawing_area;
+  public Example() {
+    Object(application_id: "my.application", flags: ApplicationFlags.FLAGS_NONE);
+    this.activate.connect(() => {
+      window = new Gtk.ApplicationWindow(this);
+      drawing_area = new Gtk.DrawingArea();
+      drawing_area.set_draw_func(draw_circle);
+      window.set_child(drawing_area);
+      window.present();
+    });
+  }
+
+  private void draw_circle(Gtk.DrawingArea area, Cairo.Context cr, int width, int height) {
+    int centerx = width / 2;
+    int centery = height / 2;
+    double anglestep = 1.0 / width;
+    for (float theta = (float) 0.0; theta < 360; theta += (float) 0.1) {
+      float r;
+      float g;
+      float b;
+      Gtk.hsv_to_rgb(theta / (float) 360.0, 1, 1, out r, out g, out b);
+      cr.set_source_rgb(r, g, b);
+      cr.line_to(centerx, centery);
+      cr.arc(centerx, centery, ((double) width) / 2.2, GLib.Math.PI * 2 * theta / 360.0, anglestep);
+      cr.line_to(centerx, centery);
+      cr.stroke();
+    }
+  }
+
+  public static int main(string[] argv) {
+    var app = new Example();
+    return app.run(argv);
+  }
+}
--- a/Task/Color-wheel/Wren/color-wheel.wren
+++ b/Task/Color-wheel/Wren/color-wheel.wren
@ -0,0 +1,37 @@
+import "graphics" for Canvas, Color
+import "dome" for Window
+import "random" for Random
+
+class Game {
+    static init() {
+        Window.title = "Color Wheel"
+        __width = 640
+        __height = 640
+        Window.resize(__width, __height)
+        Canvas.resize(__width, __height)
+        colorWheel()
+    }
+
+    static colorWheel() {
+        var cx = (__width/2).floor
+        var cy = (__height/2).floor
+        var r = (cx < cy) ? cx : cy
+        for (y in 0...__height) {
+            var dy = y - cy
+            for (x in 0...__width) {
+                var dx = x - cx
+                var dist = (dx*dx + dy*dy).sqrt
+                if (dist <= r) {
+                    var theta = dy.atan(dx)
+                    var h = (theta + Num.pi) / Num.pi * 180
+                    var col = Color.hsv(h, dist/r, 1)
+                    Canvas.pset(x, y, col)
+                }
+            }
+        }
+    }
+
+    static update() {}
+
+    static draw(alpha) {}
+}
--- a/Task/Color-wheel/XPL0/color-wheel.xpl0
+++ b/Task/Color-wheel/XPL0/color-wheel.xpl0
@ -0,0 +1,38 @@
+def  Radius = 480/2;
+real Hue, Sat, Dist, I, F, P, Q, T;
+real XX, YY, RR, GG, BB;
+int  X, Y, R, G, B;
+def  Pi = 3.141592654;
+def  V = 1.;            \Value
+[SetVid($112);          \640x480x24 graphics
+for Y:= -Radius to Radius do
+    for X:= -Radius to Radius do
+        [XX:= float(X);
+         YY:= float(Y);
+         Dist:= sqrt(XX*XX + YY*YY);
+         if Dist <= float(Radius) then
+                [Sat:= Dist/float(Radius);      \0 >= Sat <= 1
+                Hue:= ATan2(YY, XX);            \-Pi >= Hue <= Pi
+                if Hue < 0. then Hue:= Hue + 2.*Pi;
+                Hue:= Hue * 180./Pi;            \radians to degrees
+                Hue:= Hue / 60.;                \0 >= Hue < 6
+                I:= Floor(Hue);                 \integer part of Hue
+                F:= Hue - I;                    \fractional part of Hue
+                P:= 1. - Sat;
+                Q:= 1. - Sat*F;
+                T:= 1. - Sat*(1.-F);
+                case fix(I) of
+                  0:    [RR:= V;  GG:= T;  BB:= P];
+                  1:    [RR:= Q;  GG:= V;  BB:= P];
+                  2:    [RR:= P;  GG:= V;  BB:= T];
+                  3:    [RR:= P;  GG:= Q;  BB:= V];
+                  4:    [RR:= T;  GG:= P;  BB:= V];
+                  5:    [RR:= V;  GG:= P;  BB:= Q]
+                other   [exit 1];
+                R:= fix(RR*255.);
+                G:= fix(GG*255.);
+                B:= fix(BB*255.);
+                Point(X+Radius, Radius-Y, R<<16+G<<8+B);
+                ];
+        ];
+]
--- a/Task/Color-wheel/Zkl/color-wheel.zkl
+++ b/Task/Color-wheel/Zkl/color-wheel.zkl
@ -0,0 +1,32 @@
+var w=300,h=300,out=PPM(w,h);
+colorWheel(out);
+out.writeJPGFile("colorWheel.zkl.jpg");
+
+fcn colorWheel(ppm){
+   zero,R:=ppm.w/2, zero;
+   foreach x,y in (w,h){
+      v,hue:=(x - zero).toFloat().toPolar(y - zero);
+      if(v<=R){    // only render in the circle
+     if((hue = hue.toDeg())<0) hue+=360;  // (-pi..pi] to [0..2pi)
+     s:=v/R;  // scale saturation zero at center to 1 at edge
+     ppm[x,y]=hsv2rgb(hue,1.0,s);
+      }
+   }
+}
+
+fcn hsv2rgb(hue,v,s){  //  0<=H<360, 0<=v(brightness)<=1, 0<=saturation<=1
+               // --> 24 bit RGB each R,G,B in [0..255]
+   to24bit:=fcn(r,g,b,m){
+      r,g,b=((r+m)*255).toInt(),((g+m)*255).toInt(),((b+m)*255).toInt();
+      r*0x10000 + g*0x100 + b
+   };
+   c:=v*s;
+   x:=c*(1.0 - (hue.toFloat()/60%2 - 1).abs());
+   m:=v - c;
+   if     (0  <=hue< 60) return(to24bit(c,  x,  0.0,m));
+   else if(60 <=hue<120) return(to24bit(x,  c,  0.0,m));
+   else if(120<=hue<180) return(to24bit(0.0,c,  x,  m));
+   else if(180<=hue<240) return(to24bit(0.0,x,  c,  m));
+   else if(240<=hue<300) return(to24bit(x,  0.0,c,  m));
+   else          return(to24bit(c,  0.0,x,  m));
+}