HSL and RGB conversion

This code has been declared by its author to be Public Domain code.

HSL and RGB conversion by Yasha (Posted 18 years ago)
Two functions, one to convert from HSL to RGB and one to convert from RGB to HSL. Each takes three integers (as in Color() ) and returns one integer (as in ReadPixel() ). Copied (and translated!) from Wikipedia's article on HSL and HSV.
Function HSLtoRGB(H,S,L) hk#=H/255.0 sk#=S/255.0 lk#=L/255.0 If lk<0.5 Then q#=lk(1+sk):Else q#=lk+sk-(lksk) p#=2lk-q tR#=hk+0.3333:If tR>1 Then tR=tR-1 tG#=hk tB#=hk-0.3333:If tB<0 Then tB=tB+1 cR#=p:cG#=p:cB#=p If tR<0.1666 Then cR=p+((q-p)6tR) If tG<0.1666 Then cG=p+((q-p)6tG) If tB<0.1666 Then cB=p+((q-p)6tB) If tR<0.5 And tR>=0.1666 Then cR=q If tG<0.5 And tG>=0.1666 Then cG=q If tB<0.5 And tB>=0.1666 Then cB=q If tR<0.6666 And tR>=0.5 Then cR=p+((q-p)6(0.6666-tR)) If tG<0.6666 And tG>=0.5 Then cG=p+((q-p)6(0.6666-tG)) If tB<0.6666 And tB>=0.5 Then cB=p+((q-p)6(0.6666-tB)) R=255cR:G=255cG:B=255cB Return (R Shl 16) Or (G Shl 8) Or B; Or $FF000000 ;If you want an alpha value as well, add it here End Function Function RGBtoHSL(R,G,B) rk#=R/255.0:gk#=G/255.0:bk#=B/255.0 max#=rk:min#=gk If gk>max Then max=gk If bk>max Then max=bk If rk<min Then min=rk If bk<min Then min=bk If max=min h#=0:s#=0:l#=max Else If max=rk Then h#=(60(gk-bk)/(max-min)) Mod 360 If max=gk Then h#=(60(bk-rk)/(max-min)) + 120 If max=bk Then h#=(60(rk-gk)/(max-min)) + 240 l#=(max+min)/2 If l#<=0.5 Then s#=(max-min)/(2l) If l#>0.5 Then s#=(max-min)/(2-2l) EndIf hv=(h/360.0)255:sv=s255:lv=l255 HSL=(hv Shl 16) Or (sv Shl 8) Or lv; Or $FF000000 ;If you want an alpha value as well, add it here Return HSL End Function

HSL and RGB conversion by Yasha

(Posted 18 years ago)

Two functions, one to convert from HSL to RGB and one to convert from RGB to HSL. Each takes three integers (as in Color() ) and returns one integer (as in ReadPixel() ). Copied (and translated!) from Wikipedia's article on HSL and HSV.

Function HSLtoRGB(H,S,L)

hk#=H/255.0
sk#=S/255.0
lk#=L/255.0

If lk<0.5 Then q#=lk*(1+sk):Else q#=lk+sk-(lk*sk)
p#=2*lk-q

tR#=hk+0.3333:If tR>1 Then tR=tR-1
tG#=hk
tB#=hk-0.3333:If tB<0 Then tB=tB+1

cR#=p:cG#=p:cB#=p

If tR<0.1666 Then cR=p+((q-p)*6*tR)
If tG<0.1666 Then cG=p+((q-p)*6*tG)
If tB<0.1666 Then cB=p+((q-p)*6*tB)

If tR<0.5 And tR>=0.1666 Then cR=q
If tG<0.5 And tG>=0.1666 Then cG=q
If tB<0.5 And tB>=0.1666 Then cB=q

If tR<0.6666 And tR>=0.5 Then cR=p+((q-p)*6*(0.6666-tR))
If tG<0.6666 And tG>=0.5 Then cG=p+((q-p)*6*(0.6666-tG))
If tB<0.6666 And tB>=0.5 Then cB=p+((q-p)*6*(0.6666-tB))

R=255*cR:G=255*cG:B=255*cB

Return (R Shl 16) Or (G Shl 8) Or B; Or $FF000000			;If you want an alpha value as well, add it here

End Function

Function RGBtoHSL(R,G,B)

rk#=R/255.0:gk#=G/255.0:bk#=B/255.0

max#=rk:min#=gk
If gk>max Then max=gk
If bk>max Then max=bk
If rk<min Then min=rk
If bk<min Then min=bk

If max=min
    h#=0:s#=0:l#=max
Else
    If max=rk Then h#=(60*(gk-bk)/(max-min)) Mod 360
    If max=gk Then h#=(60*(bk-rk)/(max-min)) + 120
    If max=bk Then h#=(60*(rk-gk)/(max-min)) + 240
    l#=(max+min)/2
    If l#<=0.5 Then s#=(max-min)/(2*l)
    If l#>0.5 Then s#=(max-min)/(2-2*l)
EndIf

hv=(h/360.0)*255:sv=s*255:lv=l*255

HSL=(hv Shl 16) Or (sv Shl 8) Or lv; Or $FF000000			;If you want an alpha value as well, add it here

Return HSL

End Function