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author | Markus Mohrhard <markus.mohrhard@googlemail.com> | 2014-08-07 00:01:02 +0200 |
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committer | Markus Mohrhard <markus.mohrhard@googlemail.com> | 2014-08-08 09:23:59 +0200 |
commit | a7f3c73fd76b6955862a77cbb403b7b5b47582bd (patch) | |
tree | b24c12794c43cea2a098b0e4619b7d26b644e3a8 /canvas/opengl/linearMultiColorGradientFragmentShader.glsl | |
parent | 56d45b721f15946acaf1c6ee7c4c0003fbe1d554 (diff) |
extract shaders to own file and use shared shader loading
Change-Id: I1af7e03a3e46f3cb49162be9351ce22f54d08c52
Diffstat (limited to 'canvas/opengl/linearMultiColorGradientFragmentShader.glsl')
-rw-r--r-- | canvas/opengl/linearMultiColorGradientFragmentShader.glsl | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/canvas/opengl/linearMultiColorGradientFragmentShader.glsl b/canvas/opengl/linearMultiColorGradientFragmentShader.glsl new file mode 100644 index 000000000000..a3f3358c592b --- /dev/null +++ b/canvas/opengl/linearMultiColorGradientFragmentShader.glsl @@ -0,0 +1,45 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#version 120 + +uniform int i_nColors; +uniform sampler1D t_colorArray4d; +uniform sampler1D t_stopArray1d; +uniform mat3x2 m_transform; +varying vec2 v_textureCoords2d; + +int findBucket(float t) +{ + int nMinBucket=0; + while( nMinBucket < i_nColors && + texture1D(t_stopArray1d, nMinBucket).s < t ) + ++nMinBucket; + return max(nMinBucket-1,0); +} + +void main(void) +{ + const float fAlpha = + clamp( (m_transform * vec3(v_textureCoords2d,1)).s, + 0.0, 1.0 ); + + const int nMinBucket=findBucket( fAlpha ); + + const float fLerp = + (fAlpha-texture1D(t_stopArray1d, nMinBucket).s) / + (texture1D(t_stopArray1d, nMinBucket+1).s - + texture1D(t_stopArray1d, nMinBucket).s); + + gl_FragColor = mix(texture1D(t_colorArray4d, nMinBucket), + texture1D(t_colorArray4d, nMinBucket+1), + fLerp); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |