History of rgb2hsl

== Syntax ==

int rgb2hsl(int r, int g, int b, int z)

== Arguments ==

:r

::Red value

:g

::Green value

:b

::Blue value

:z

::Determines which value is returned. z=0 for H (Hue), z=1 for S (Saturation), z=2 for L (Lightness)

== Return ==

Returns the H, S or L value from 0 to 255 depending on the value of z

== Description ==

Lets you convert RGB values to HSL values.

== Example ==

<code>

%ffp

ctl(0): "Adjust H", Range=(-255,255), val=0

ctl(1): "Adjust S", Range=(-255,255), val=0

ctl(2): "Adjust L", Range=(-255,255), val=0

ForEveryTile:{

int r,g,b,h,s,l;

for (y= y_start; y &lt; y_end; y++) {

if (updateProgress(y, y_end)) abort();

for (x = x_start; x &lt; x_end; x++) {

r = src(x,y,0);

g = src(x,y,1);

b = src(x,y,2);

h = rgb2hsl (r,g,b,0);

s = rgb2hsl (r,g,b,1);

l = rgb2hsl (r,g,b,2);

// Do the HSL adjustment

h = h + ctl(0);

s = s + ctl(1);

l = l + ctl(2);

pset( x, y, 0, hsl2rgb (h,s,l,0) );

pset( x, y, 1, hsl2rgb (h,s,l,1) );

pset( x, y, 2, hsl2rgb (h,s,l,2) );

}

}

return true;

</code>

== See Also ==

hsl2rgb