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 tex;
26 vec2 tex_size = vec2 (width, height);
27 vec2 texturecoord = gl_TexCoord[0].xy;
29 normcoord = texturecoord / tex_size - 1.0;
30 float r = length (normcoord);
31 normcoord *= 1.0 + smoothstep(0.25, 0.5, abs(normcoord));
32 normcoord /= 2.0; /* zoom amount */
33 texturecoord = (normcoord + 1.0) * tex_size;
34 vec4 color = texture2DRect (tex, texturecoord);
35 gl_FragColor = color * gl_Color;