mirror of
https://github.com/scratchfoundation/bgfx.git
synced 2024-11-25 17:18:12 -05:00
52 lines
1.9 KiB
Markdown
52 lines
1.9 KiB
Markdown
GLSL optimizer
|
|
==============
|
|
|
|
A C++ library that takes GLSL shaders, does some GPU-independent optimizations on them
|
|
and outputs GLSL back. Optimizations are function inlining, dead code removal, copy propagation,
|
|
constant folding, constant propagation, arithmetic optimizations and so on.
|
|
|
|
Apparently quite a few mobile platforms are pretty bad at optimizing GLSL shaders; and
|
|
unfortunately they *also* lack offline shader compilers. So using a GLSL optimizer offline
|
|
before can make the shader run much faster on a platform like that. See performance numbers
|
|
in [this blog post](http://aras-p.info/blog/2010/09/29/glsl-optimizer/).
|
|
|
|
Almost all actual code is [Mesa 3D's GLSL](http://cgit.freedesktop.org/mesa/mesa/log/)
|
|
compiler; all this library does is spits out optimized GLSL back, and adds GLES type precision
|
|
handling to the optimizer.
|
|
|
|
This GLSL optimizer is made for [Unity's](http://unity3d.com/) purposes and is built-in
|
|
in [Unity 3](http://unity3d.com/unity/whats-new/unity-3) and later.
|
|
|
|
GLSL Optimizer is licensed according to the terms of the MIT license.
|
|
|
|
|
|
Usage
|
|
-----
|
|
|
|
Visual Studio 2008 (Windows, x86) and Xcode 4.5+ (Mac, i386) project files for a static
|
|
library are provided in `src/glsl/msvc/mesaglsl2.vcproj` and `src/glsl/xcode/mesaglsl2`
|
|
respectively.
|
|
|
|
For Linux you can use cmake. Just type "cmake . && make" in the root directory.
|
|
This will build the optimizer library and some executable binaries.
|
|
|
|
Interface for the library is `src/glsl/glsl_optimizer.h`. General usage is:
|
|
|
|
ctx = glslopt_initialize();
|
|
for (lots of shaders) {
|
|
shader = glslopt_optimize (ctx, shaderType, shaderSource, options);
|
|
if (glslopt_get_status (shader)) {
|
|
newSource = glslopt_get_output (shader);
|
|
} else {
|
|
errorLog = glslopt_get_log (shader);
|
|
}
|
|
glslopt_shader_delete (shader);
|
|
}
|
|
glslopt_cleanup (ctx);
|
|
|
|
Notes
|
|
-----
|
|
|
|
* GLSL versions 1.10 and 1.20 are supported. 1.10 is the default, use #version 120 to specify
|
|
1.20.
|
|
* GLSL ES version 1.00 is supported.
|