diff options
Diffstat (limited to 'intern/cycles/render/filter.cpp')
| -rw-r--r-- | intern/cycles/render/filter.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/intern/cycles/render/filter.cpp b/intern/cycles/render/filter.cpp new file mode 100644 index 00000000000..d7682bedc12 --- /dev/null +++ b/intern/cycles/render/filter.cpp @@ -0,0 +1,129 @@ +/* + * Copyright 2011, Blender Foundation. + * + * 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. + */ + +#include "camera.h" +#include "device.h" +#include "filter.h" +#include "scene.h" + +#include "util_algorithm.h" +#include "util_debug.h" +#include "util_math.h" + +CCL_NAMESPACE_BEGIN + +Filter::Filter() +{ + filter_type = FILTER_BOX; + filter_width = 1.0f; + need_update = true; +} + +Filter::~Filter() +{ +} + +static float filter_func_box(float v, float width) +{ + return (float)1; +} + +static float filter_func_gaussian(float v, float width) +{ + v *= (float)2/width; + return (float)expf((float)-2*v*v); +} + +static vector<float> filter_table(FilterType type, float width) +{ + const int filter_table_size = 256; + vector<float> filter_table_cdf(filter_table_size+1); + vector<float> filter_table(filter_table_size+1); + float (*filter_func)(float, float) = NULL; + int i, half_size = filter_table_size/2; + + switch(type) { + case FILTER_BOX: + filter_func = filter_func_box; + break; + case FILTER_GAUSSIAN: + filter_func = filter_func_gaussian; + break; + default: + assert(0); + } + + /* compute cumulative distribution function */ + filter_table_cdf[0] = 0.0f; + + for(i=0; i<filter_table_size; i++) { + float x = i*width*0.5f/(filter_table_size-1); + float y = filter_func(x, width); + filter_table_cdf[i+1] += filter_table_cdf[i] + fabsf(y); + } + + for(i=0; i<=filter_table_size; i++) + filter_table_cdf[i] /= filter_table_cdf[filter_table_size]; + + /* create importance sampling table */ + for(i=0; i<=half_size; i++) { + float x = i/(float)half_size; + int index = upper_bound(filter_table_cdf.begin(), filter_table_cdf.end(), x) - filter_table_cdf.begin(); + float t; + + if(index < filter_table_size+1) { + t = (x - filter_table_cdf[index])/(filter_table_cdf[index+1] - filter_table_cdf[index]); + } + else { + t = 0.0f; + index = filter_table_size; + } + + float y = ((index + t)/(filter_table_size))*width; + + filter_table[half_size+i] = 0.5f*(1.0f + y); + filter_table[half_size-i] = 0.5f*(1.0f - y); + } + + return filter_table; +} + +void Filter::device_update(Device *device, DeviceScene *dscene) +{ + if(!need_update) + return; + + device_free(device, dscene); + + /* update __filter_table */ + vector<float> table = filter_table(filter_type, filter_width); + + dscene->filter_table.copy(&table[0], table.size()); + device->tex_alloc("__filter_table", dscene->filter_table, true); + + need_update = false; +} + +void Filter::device_free(Device *device, DeviceScene *dscene) +{ + device->tex_free(dscene->filter_table); + dscene->filter_table.clear(); +} + +CCL_NAMESPACE_END + |