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add then :) 

SVN revision: 4746
This commit is contained in:
Carsten Haitzler 2001-05-09 01:57:02 +00:00
parent fee04bcdde
commit 02a6912ad4
2 changed files with 198 additions and 0 deletions
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189
src/color_helpers.c Normal file
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#include "color_helpers.h"
/*
* Color space conversion helper routines
* Convert between rgb and hsv adn between rgb and hls
*/
void
__imlib_rgb_to_hsv(int r, int g, int b, float *hue, float *saturation, float *value)
{
int f;
float i,j,k,max,min,d;
i = ((float)r)/255.0;
j = ((float)g)/255.0;
k = ((float)b)/255.0;
f = 0;
max = min = i;
if (j>max) { max = j; f = 1; } else min = j;
if (k>max) { max = k; f = 2; } else if (k<min) min = k;
d = max - min;
*value = max;
if (max!=0) *saturation = d/max; else *saturation = 0;
if (*saturation==0)
*hue = 0;
else
{
switch (f)
{
case 0:
*hue = (j - k)/d;
break;
case 1:
*hue = 2 + (k - i)/d;
break;
case 2:
*hue = 4 + (i - j)/d;
break;
}
*hue *= 60.0;
if (*hue<0) *hue += 360.0;
}
}
void
__imlib_hsv_to_rgb(float hue, float saturation, float value, int *r, int *g, int *b)
{
int i,p,q,t,h;
float vs,vsf;
i = (int)(value*255.0);
if (saturation==0)
*r = *g = *b = i;
else
{
if (hue==360) hue = 0;
hue = hue/60.0;
h = (int)hue;
vs = value * saturation;
vsf = vs * (hue - h);
p = (int)(255.0 * (value - vs));
q = (int)(255.0 * (value - vsf));
t = (int)(255.0 * (value - vs + vsf));
switch (h)
{
case 0:
*r = i;
*g = t;
*b = p;
break;
case 1:
*r = q;
*g = i;
*b = p;
break;
case 2:
*r = p;
*g = i;
*b = t;
break;
case 3:
*r = p;
*g = q;
*b = i;
break;
case 4:
*r = t;
*g = p;
*b = i;
break;
case 5:
*r = i;
*g = p;
*b = q;
break;
}
}
}
void
__imlib_rgb_to_hls(int r, int g, int b, float *hue, float *lightness, float *saturation)
{
int f;
float i,j,k,max,min,d;
i = ((float)r)/255.0;
j = ((float)g)/255.0;
k = ((float)b)/255.0;
f = 0;
max = min = i;
if (j>max) { max = j; f = 1; } else min = j;
if (k>max) { max = k; f = 2; } else if (k<min) min = k;
d = max - min;
*lightness = (max + min)/2.0;
if (d==0)
{
*saturation = 0;
*hue = 0;
}
else
{
if (*lightness < 0.5) *saturation = d/(max + min); else *saturation = d/(2 - max - min);
switch (f)
{
case 0:
*hue = (j - k)/d;
break;
case 1:
*hue = 2 + (k - i)/d;
break;
case 2:
*hue = 4 + (i - j)/d;
break;
}
*hue *= 60.0;
if (*hue<0) *hue += 360.0;
}
}
void
__imlib_hls_to_rgb(float hue, float lightness, float saturation, int *r, int *g, int *b)
{
float m1,m2,m21,h;
if (saturation==0)
*r = *g = *b = (int)(lightness * 255.0);
else
{
if (lightness<=0.5)
m2 = lightness * (1 + saturation);
else
m2 = lightness + saturation + lightness * saturation;
m1 = 2 * lightness - m2;
m21 = m2 - m1;
h = hue + 120;
if (h>360) h -= 360; else if (h<0) h += 360;
if (h<60)
*r = (int)(255.0 * (m1 + m21 * h/60.0));
else if (h<180)
*r = (int)(255.0 * m2);
else if (h<240)
*r = (int)(255.0 * (m1 + m21 * (240.0 - h)/60.0));
else
*r = (int)(255.0 * m1);
h = hue;
if (h>360) h -= 360; else if (h<0) h += 360;
if (h<60)
*g = (int)(255.0 * (m1 + m21 * h/60.0));
else if (h<180)
*g = (int)(255.0 * m2);
else if (h<240)
*g = (int)(255.0 * (m1 + m21 * (240.0 - h)/60.0));
else
*g = (int)(255.0 * m1);
h = hue - 120;
if (h>360) h -= 360; else if (h<0) h += 360;
if (h<60)
*b = (int)(255.0 * (m1 + m21 * h/60.0));
else if (h<180)
*b = (int)(255.0 * m2);
else if (h<240)
*b = (int)(255.0 * (m1 + m21 * (240.0 - h)/60.0));
else
*b = (int)(255.0 * m1);
}
}

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src/color_helpers.h Normal file
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#ifndef __COLOR_HELPERS
#define __COLOR_HELPERS 1
void __imlib_rgb_to_hsv(int r, int g, int b, float *hue, float *saturation, float *value);
void __imlib_hsv_to_rgb(float hue, float saturation, float value, int *r, int *g, int *b);
void __imlib_rgb_to_hls(int r, int g, int b, float *hue, float *lightness, float *saturation);
void __imlib_hls_to_rgb(float hue, float lightness, float saturation, int *r, int *g, int *b);
#endif