3 * Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
21 #extension GL_ARB_texture_rectangle : enable
22 uniform sampler2DRect saved;
23 uniform sampler2DRect current;
25 vec4 savedcolor = texture2DRect (saved, gl_TexCoord[0].st);
26 vec4 currentcolor = texture2DRect (current, gl_TexCoord[0].st);
27 gl_FragColor = vec4 (step (0.12, length (savedcolor - currentcolor)));