Blender V2.61 - r43446

RAS_Sobel2DFilter.h

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00001 /*
00002  * ***** BEGIN GPL LICENSE BLOCK *****
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  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
00019  * All rights reserved.
00020  *
00021  * The Original Code is: all of this file.
00022  *
00023  * Contributor(s): none yet.
00024  *
00025  * ***** END GPL LICENSE BLOCK *****
00026  */
00027 
00032 #ifndef __RAS_SOBEL2DFILTER
00033 #define __RAS_SOBEL2DFILTER
00034 
00035 const char * SobelFragmentShader=STRINGIFY(
00036 uniform sampler2D bgl_RenderedTexture;
00037 uniform vec2 bgl_TextureCoordinateOffset[9];
00038 
00039 void main(void)
00040 {
00041     vec4 sample[9];
00042 
00043     for (int i = 0; i < 9; i++)
00044     {
00045         sample[i] = texture2D(bgl_RenderedTexture,
00046                               gl_TexCoord[0].st + bgl_TextureCoordinateOffset[i]);
00047     }
00048 
00049     vec4 horizEdge = sample[2] + (2.0*sample[5]) + sample[8] -
00050             (sample[0] + (2.0*sample[3]) + sample[6]);
00051 
00052     vec4 vertEdge = sample[0] + (2.0*sample[1]) + sample[2] -
00053             (sample[6] + (2.0*sample[7]) + sample[8]);
00054 
00055     gl_FragColor.rgb = sqrt((horizEdge.rgb * horizEdge.rgb) +
00056                             (vertEdge.rgb * vertEdge.rgb));
00057     gl_FragColor.a = 1.0;
00058 }
00059 );
00060 #endif
00061