Rosetta Code

Color wheel: Difference between revisions

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Color wheel (view source)

Revision as of 12:24, 29 October 2022

2,543 bytes added ,  1 year ago
Added C# implementation
(added image)
(Added C# implementation)
Line 148:
{{out}}
[[Media:Colorwheel cpp.png]]
 
=={{header|C#}}==
 
<syntaxhighlight lang="csharp">
// constructor of main window
public MainWindow()
{
InitializeComponent();
RenderOptions.SetBitmapScalingMode(imgMain, BitmapScalingMode.HighQuality);
imgMain.Source = new WriteableBitmap(480, 480, 96, 96, PixelFormats.Bgr32, null);
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;
</syntaxhighlight>
 
{{out}}
[[File:ColorRing.PNG]]
 
 
=={{header|Delphi}}==
Line 728 ⟶ 801:
<syntaxhighlight lang="lua">
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
end
end
love.graphics.setCanvas()
end
 
function love.draw()
love.graphics.setColor (1,1,1)
love.graphics.draw (canvas)
end
</syntaxhighlight>
Line 1,290 ⟶ 1,363:
' -----------------------------------
global pi
pi = 22 / 7
steps = 1
 
graphic #g, 525, 525
Line 1,297 ⟶ 1,370:
 
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$, 3))
p = ((x -270)^2 +(y -270)^2)^0.5 / 250
r = min(255,p * red)
g = min(255,p * grn)
b = min(255,p * blu)
if p > 1 then #g "color white" else #g color(r,g,b)
#g "set "; x; " "; y
next y
next x
render #g
Line 1,325 ⟶ 1,398:
function atan2(y,x)
if (x = 0) and (y <> 0) then
r$ = "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</syntaxhighlight>
Line 1,876 ⟶ 1,949:
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);
}
}
Line 1,884 ⟶ 1,957:
 
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();
Line 1,897 ⟶ 1,970:
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));
}</syntaxhighlight>
{{out}}
Pogromizd
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