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52 lines
1.9 KiB
Markdown
52 lines
1.9 KiB
Markdown
GLSL optimizer
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==============
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A C++ library that takes GLSL shaders, does some GPU-independent optimizations on them
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and outputs GLSL back. Optimizations are function inlining, dead code removal, copy propagation,
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constant folding, constant propagation, arithmetic optimizations and so on.
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Apparently quite a few mobile platforms are pretty bad at optimizing GLSL shaders; and
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unfortunately they *also* lack offline shader compilers. So using a GLSL optimizer offline
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before can make the shader run much faster on a platform like that. See performance numbers
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in [this blog post](http://aras-p.info/blog/2010/09/29/glsl-optimizer/).
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Almost all actual code is [Mesa 3D's GLSL](http://cgit.freedesktop.org/mesa/mesa/log/)
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compiler; all this library does is spits out optimized GLSL back, and adds GLES type precision
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handling to the optimizer.
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This GLSL optimizer is made for [Unity's](http://unity3d.com/) purposes and is built-in
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in [Unity 3](http://unity3d.com/unity/whats-new/unity-3) and later.
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GLSL Optimizer is licensed according to the terms of the MIT license.
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Usage
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-----
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Visual Studio 2008 (Windows, x86) and Xcode 3.2 (Mac, i386) project files for a static
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library are provided in `src/glsl/msvc/mesaglsl2.vcproj` and `src/glsl/xcode/mesaglsl2`
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respectively.
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For Linux you can use cmake. Just type "cmake . && make" in the root directory.
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This will build the optimizer library and some executable binaries.
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Interface for the library is `src/glsl/glsl_optimizer.h`. General usage is:
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ctx = glslopt_initialize();
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for (lots of shaders) {
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shader = glslopt_optimize (ctx, shaderType, shaderSource, options);
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if (glslopt_get_status (shader)) {
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newSource = glslopt_get_output (shader);
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} else {
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errorLog = glslopt_get_log (shader);
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}
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glslopt_shader_delete (shader);
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}
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glslopt_cleanup (ctx);
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Notes
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-----
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* GLSL versions 1.10 and 1.20 are supported. 1.10 is the default, use #version 120 to specify
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1.20.
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* GLSL ES version 1.00 is supported.
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