diff options
author | Rainer Hochecker <fernetmenta@online.de> | 2017-09-27 14:35:53 +0200 |
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committer | Rainer Hochecker <fernetmenta@online.de> | 2017-10-05 18:06:31 +0200 |
commit | d7f825e3861629a55a66111a8ac5f4519f835c1f (patch) | |
tree | a5147dbcbeb9faf61eaf36d0f321d0aa7947db90 /system/shaders/GL/1.5/gl_streatch.glsl | |
parent | e889fa1382babbac37380ea1b65859c603f86bde (diff) |
OpenGL: migrate to 3.2, WIP
Diffstat (limited to 'system/shaders/GL/1.5/gl_streatch.glsl')
-rw-r--r-- | system/shaders/GL/1.5/gl_streatch.glsl | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/system/shaders/GL/1.5/gl_streatch.glsl b/system/shaders/GL/1.5/gl_streatch.glsl new file mode 100644 index 0000000000..dc42318d50 --- /dev/null +++ b/system/shaders/GL/1.5/gl_streatch.glsl @@ -0,0 +1,40 @@ +/* + * Copyright (C) 2010-2013 Team XBMC + * http://xbmc.org + * + * 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, 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 XBMC; see the file COPYING. If not, see + * <http://www.gnu.org/licenses/>. + * + */ + +#version 120 + +uniform sampler2D img; +uniform float m_stretch; +varying vec2 m_cord; + +vec2 stretch(vec2 pos) +{ + // our transform should map [0..1] to itself, with f(0) = 0, f(1) = 1, f(0.5) = 0.5, and f'(0.5) = b. + // a simple curve to do this is g(x) = b(x-0.5) + (1-b)2^(n-1)(x-0.5)^n + 0.5 + // where the power preserves sign. n = 2 is the simplest non-linear case (required when b != 1) + float x = pos.x - 0.5; + return vec2(mix(x * abs(x) * 2.0, x, m_stretch) + 0.5, pos.y); +} + +void main() +{ + gl_FragColor.rgb = texture2D(img, stretch(m_cord)).rgb; + gl_FragColor.a = gl_Color.a; +} |