// HSL-2-RGB
void hsl2rgb(t_cs *x, int h, int s, int l)
{
long red, green, blue;
double m1,m2,tr,tg,tb, hue, lightness, saturation;
// scale to floating point... number range should be 360, 1, 1
hue = (float)h;
//hue = ((hue/255.)*360.);
saturation = (float)s/100.0;
lightness = (float)l/100.0;
if (lightness <= 0.5) m2 = lightness*(1.0+saturation);
else m2 = lightness+saturation-lightness*saturation;
m1 = 2.0*lightness-m2;
if (saturation == 0.0){
tr = lightness;
tg = lightness;
tb = lightness;
}
else{
tr = hls_value(m1,m2,hue+120.);
tg = hls_value(m1,m2,hue);
tb = hls_value(m1,m2,hue-120.);
}
red = (int)(tr*255.);
green = (int)(tg*255.);
blue = (int)(tb*255.);
x->calc1 = red;
x->calc2 = green;
x->calc3 = blue;
}
void HSLUnit::convertToNeutral(const TTValue& input, TTValue& output)
{
double h = input.getFloat64(0);// input.getFloat64(0);
double s = input.getFloat64(1);// input.getFloat64(1);
double l = input.getFloat64(2);// input.getFloat64(2);
double red, green, blue;
double m1, m2, hue, lightness, saturation;
// scale to floating point... number range should be 360, 1, 1
hue = h;
saturation = s/100.0;
lightness = l/100.0;
if(lightness <= 0.5)
m2 = lightness*(1.0+saturation);
else
m2 = lightness+saturation-lightness*saturation;
m1 = 2.0 * lightness-m2;
if(saturation == 0.0){
red = lightness;
green = lightness;
blue = lightness;
}
else{
red = hls_value(m1, m2, hue+120.0);
green = hls_value(m1, m2, hue);
blue = hls_value(m1, m2, hue-120.0);
}
output.setSize(3);
output.set(0, red);
output.set(1, green);
output.set(2, blue);
}
/**
* Convert HLS to RGB.
*
* The HLS color system describes a color based on the qualities of
* hue, lightness, and saturation. A particular color has three
* coordinates, (H,L,S). The L and S coordinates must be between
* 0 and 1, while the H coordinate must be between 0 and 360, and
* is interpreted as an angle.
*
* The RGB color system describes a color based on the amounts of the
* base colors red, green, and blue. Thus, a particular color
* has three coordinates, (R,G,B). Each coordinate must be between
* 0 and 1.
*/
void HLS_to_RGB(float H, float L, float S, float &R, float &G, float &B) {
float m1, m2;
if (L <= 0.5) {
m2 = L + L*S;
} else {
m2 = L + S - L*S;
}
m1 = 2.0f * L - m2;
if (S == 0.0) {
R = G = B = L;
} else {
R = hls_value(m1, m2, H + 120.0f);
G = hls_value(m1, m2, H);
B = hls_value(m1, m2, H - 120.0f);
}
}
PLPixel24 hls2rgb (double h, double l, double s)
{
double m1, m2;
l /= 255;
s /= 100;
// Warning: Foley, van Dam has a typo on the next line!
m2 = (l<=0.5)?(l*(1.0+s)):(l+s-l*s);
m1 = 2.0*l-m2;
if (s<0.001)
return PLPixel24(PLBYTE(l*255), PLBYTE(l*255), PLBYTE(l*255));
else
{
return PLPixel24(hls_value(m1,m2,h+120.0),
hls_value(m1,m2,h),
hls_value(m1,m2,h-120.0));
}
}
inline
void hls_to_rgb(float h, float l, float s, float &r, float &g, float &b) {
/* Given: h in [0,360] or UNDEFINED, l and s in [0,1]
* Desired: r, g, b each in [0,1]
*/
float m1,m2;
m2 = (l<=0.5f)?(l+l*s):(l+s-l*s);
m1 = (2.0f*l-m2);
if (s==0.0f)
r=g=b=l;
else {
r = hls_value(m1, m2, h+120.0f);
g = hls_value(m1, m2, h);
b = hls_value(m1, m2, h-120.0f);
}
}
