Blender V2.61 - r43446

svm_hsv.h

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00001 /*
00002  * Copyright 2011, Blender Foundation.
00003  *
00004  * This program is free software; you can redistribute it and/or
00005  * modify it under the terms of the GNU General Public License
00006  * as published by the Free Software Foundation; either version 2
00007  * of the License, or (at your option) any later version.
00008  *
00009  * This program is distributed in the hope that it will be useful,
00010  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012  * GNU General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU General Public License
00015  * along with this program; if not, write to the Free Software Foundation,
00016  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
00017  */
00018 
00019 #ifndef __SVM_HSV_H__
00020 #define __SVM_HSV_H__
00021 
00022 CCL_NAMESPACE_BEGIN
00023 
00024 __device float3 rgb_to_hsv(float3 rgb)
00025 {
00026     float cmax, cmin, h, s, v, cdelta;
00027     float3 c;
00028 
00029     cmax = fmaxf(rgb.x, fmaxf(rgb.y, rgb.z));
00030     cmin = min(rgb.x, min(rgb.y, rgb.z));
00031     cdelta = cmax - cmin;
00032 
00033     v = cmax;
00034 
00035     if(cmax != 0.0f) {
00036         s = cdelta/cmax;
00037     }
00038     else {
00039         s = 0.0f;
00040         h = 0.0f;
00041     }
00042 
00043     if(s == 0.0f) {
00044         h = 0.0f;
00045     }
00046     else {
00047         float3 cmax3 = make_float3(cmax, cmax, cmax);
00048         c = (cmax3 - rgb)/cdelta;
00049 
00050         if(rgb.x == cmax) h = c.z - c.y;
00051         else if(rgb.y == cmax) h = 2.0f + c.x -  c.z;
00052         else h = 4.0f + c.y - c.x;
00053 
00054         h /= 6.0f;
00055 
00056         if(h < 0.0f)
00057             h += 1.0f;
00058     }
00059 
00060     return make_float3(h, s, v);
00061 }
00062 
00063 __device float3 hsv_to_rgb(float3 hsv)
00064 {
00065     float i, f, p, q, t, h, s, v;
00066     float3 rgb;
00067 
00068     h = hsv.x;
00069     s = hsv.y;
00070     v = hsv.z;
00071 
00072     if(s==0.0f) {
00073         rgb = make_float3(v, v, v);
00074     }
00075     else {
00076         if(h==1.0f)
00077             h = 0.0f;
00078         
00079         h *= 6.0f;
00080         i = floor(h);
00081         f = h - i;
00082         rgb = make_float3(f, f, f);
00083         p = v*(1.0f-s);
00084         q = v*(1.0f-(s*f));
00085         t = v*(1.0f-(s*(1.0f-f)));
00086         
00087         if(i == 0.0f) rgb = make_float3(v, t, p);
00088         else if(i == 1.0f) rgb = make_float3(q, v, p);
00089         else if(i == 2.0f) rgb = make_float3(p, v, t);
00090         else if(i == 3.0f) rgb = make_float3(p, q, v);
00091         else if(i == 4.0f) rgb = make_float3(t, p, v);
00092         else rgb = make_float3(v, p, q);
00093     }
00094 
00095     return rgb;
00096 }
00097 
00098 __device void svm_node_hsv(KernelGlobals *kg, ShaderData *sd, float *stack, uint in_color_offset, uint fac_offset, uint out_color_offset, int *offset)
00099 {
00100     /* read extra data */
00101     uint4 node1 = read_node(kg, offset);
00102 
00103     float fac = stack_load_float(stack, fac_offset);
00104     float3 in_color = stack_load_float3(stack, in_color_offset);
00105     float3 color = in_color;
00106 
00107     float hue = stack_load_float(stack, node1.y);
00108     float sat = stack_load_float(stack, node1.z);
00109     float val = stack_load_float(stack, node1.w);
00110 
00111     color = rgb_to_hsv(color);
00112 
00113     // remember: fmod doesn't work for negative numbers
00114     color.x += hue + 0.5f;
00115     color.x = fmod(color.x, 1.0f);
00116     color.y *= sat;
00117     color.z *= val;
00118 
00119     color = hsv_to_rgb(color);
00120 
00121     color.x = fac*color.x + (1.0f - fac)*in_color.x;
00122     color.y = fac*color.y + (1.0f - fac)*in_color.y;
00123     color.z = fac*color.z + (1.0f - fac)*in_color.z;
00124 
00125     if (stack_valid(out_color_offset))
00126         stack_store_float3(stack, out_color_offset, color);
00127 }
00128 
00129 CCL_NAMESPACE_END
00130 
00131 #endif /* __SVM_HSV_H__ */
00132