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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/* Color Management */
float color_srgb_to_scene_linear(float c)
{
if (c < 0.04045)
return (c < 0.0) ? 0.0 : c * (1.0 / 12.92);
else
return pow((c + 0.055) * (1.0 / 1.055), 2.4);
}
float color_scene_linear_to_srgb(float c)
{
if (c < 0.0031308)
return (c < 0.0) ? 0.0 : c * 12.92;
else
return 1.055 * pow(c, 1.0 / 2.4) - 0.055;
}
color color_srgb_to_scene_linear(color c)
{
return color(
color_srgb_to_scene_linear(c[0]),
color_srgb_to_scene_linear(c[1]),
color_srgb_to_scene_linear(c[2]));
}
color color_scene_linear_to_srgb(color c)
{
return color(
color_scene_linear_to_srgb(c[0]),
color_scene_linear_to_srgb(c[1]),
color_scene_linear_to_srgb(c[2]));
}
/* Color Operations */
color rgb_to_hsv(color rgb)
{
float cmax, cmin, h, s, v, cdelta;
color c;
cmax = max(rgb[0], max(rgb[1], rgb[2]));
cmin = min(rgb[0], min(rgb[1], rgb[2]));
cdelta = cmax - cmin;
v = cmax;
if (cmax != 0.0) {
s = cdelta / cmax;
}
else {
s = 0.0;
h = 0.0;
}
if (s == 0.0) {
h = 0.0;
}
else {
c = (color(cmax, cmax, cmax) - rgb) / cdelta;
if (rgb[0] == cmax) h = c[2] - c[1];
else if (rgb[1] == cmax) h = 2.0 + c[0] - c[2];
else h = 4.0 + c[1] - c[0];
h /= 6.0;
if (h < 0.0)
h += 1.0;
}
return color(h, s, v);
}
color hsv_to_rgb(color hsv)
{
float i, f, p, q, t, h, s, v;
color rgb;
h = hsv[0];
s = hsv[1];
v = hsv[2];
if (s == 0.0) {
rgb = color(v, v, v);
}
else {
if (h == 1.0)
h = 0.0;
h *= 6.0;
i = floor(h);
f = h - i;
rgb = color(f, f, f);
p = v * (1.0 - s);
q = v * (1.0 - (s * f));
t = v * (1.0 - (s * (1.0 - f)));
if (i == 0.0) rgb = color(v, t, p);
else if (i == 1.0) rgb = color(q, v, p);
else if (i == 2.0) rgb = color(p, v, t);
else if (i == 3.0) rgb = color(p, q, v);
else if (i == 4.0) rgb = color(t, p, v);
else rgb = color(v, p, q);
}
return rgb;
}
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