Hello and happy new year 2024!
Inspired by this thread, I intend to propose a new G'MIC filter "Color Wheel".
With default parameters, it would give:
Attachment:
colorWheel1.jpg [ 31.3 KiB | Viewed 1077 times ]
With default parameters except that "Internal Circle Radius Percentage = 1, Type = Opponent Model", it would give:
Attachment:
colorWheel_1_1_OM.jpg [ 29.21 KiB | Viewed 1077 times ]
With default parameters except that "Internal Circle Radius Percentage = 50, Parts = x3, Type = Red-Yellow-Blue Model", it would give:
Attachment:
colorWheel_50_3_RYB.jpg [ 34.72 KiB | Viewed 1077 times ]
Here is its code:
Code: Select all
#@gui Color Wheel (prerelease): cl_colorWheel_prerelease, cl_colorWheel_prerelease(0)
#@gui : note = note("Warning: This is an enormously gross approximation of the color models.")
#@gui : note = note("<b>Dimension:</b>")
#@gui : External Circle Radius = float(200, 10, 1000)
#@gui : Internal Circle Radius Percentage = float(80, 1, 99)
#@gui : Parts = choice[0, "x1", "x2", "x3", "x4", "Continuous"]
#@gui : sep = separator()
#@gui : note = note("<b>Colors:</b>")
#@gui : Type = choice[0, "Red-Green-Blue Model", "Red-Yellow-Blue Model", "Opponent Model"]
#@gui : sep = separator()
#@gui : note = note("<b>Rotation:</b>")
#@gui : Inverse Order = bool(0)
#@gui : Rotation = float(0, 0, 360)
#@gui : sep = separator()
#@gui : note = note("<small>Author: <i>Claude Lion</i>. Latest Update: <i>2024/01/23</i>.</small>")
cl_colorWheel_prerelease:
extCircle,intCirclePercent,parts,type,invert,rot=$*
wid={$extCircle*2.5}
hig=$wid
intCircle={$extCircle*$intCirclePercent/100}
if $type==2
base=2
else
base=3
fi
if $parts<=3
mult={$parts+1}
else
mult=60
fi
nbParts={$base*$mult}
if $type==0
formula="ang"
elif $type==1
formula="if(ang<120,ang/2,if(ang<180,ang-60,if(ang<240,ang*2-240,ang)))"
elif $type==2
formula="if(ang<180,ang*2/3,ang*4/3-120)"
fi
$wid,$hig,1,1
local.
fill. "r = sqrt((x-w/2)^2+ (y-h/2)^2);
ang=atan2(y-h/2,x-w/2);
"angd=((1-2*$invert)*ang-$rot*pi/180+pi);"
"ang=(angd/2/pi-floor(angd/2/pi))*2*pi-pi;"
"angp=$nbParts*ang/pi+0.5;"
"rnd=floor(angp);"
"frc=angp-rnd;"
"ang=(rnd-1+cut(frc*r*pi/$nbParts,0,1))*pi/$nbParts;"
ang=180*ang/pi+180;
"ang=$formula;"
"($intCircle<r&&r<$extCircle)*ang"
"
$wid,$hig,1,1,1
$wid,$hig,1,1,1
$wid,$hig,1,1,1
fill. "r = sqrt((x-w/2)^2+ (y-h/2)^2);
"cut(r-$intCircle,0,1)*cut($extCircle-r,0,1)*255"
"
a c
hsv2rgb.
done
mv[-1] 0
Installation:
- Copy and paste the above code into the file "~/.gmic" on Linux or the file "%APPDATA%\user.gmic" on Windows.
- The new filter appears in "Filters -> G'MIC -> Rendering -> Color Wheel (prerelease)".
Have fun!
. Maybe, it would be better placed in the "Colors" category! 
)