94 lines
3.2 KiB
Markdown
94 lines
3.2 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
|
|
starting with Unity 3.0.
|
|
|
|
GLSL Optimizer is licensed according to the terms of the MIT license.
|
|
|
|
See badly maintained [change log](Changelog.md).
|
|
|
|
|
|
Usage
|
|
-----
|
|
|
|
Visual Studio 2010 (Windows, x86/x64) and Xcode 5+ (Mac, i386) project files for a static
|
|
library are provided in `projects/vs2010/glsl_optimizer.sln` and `projects/xcode5/glsl_optimizer_lib`
|
|
respectively.
|
|
|
|
> Note: only the VS and Xcode project files are maintained and should work at any time.
|
|
> There's also a cmake and gyp build system for Linux et al., and some stuff in contrib folder -
|
|
> all that may or might not work.
|
|
|
|
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);
|
|
|
|
|
|
Tests
|
|
-----
|
|
|
|
There's a testing suite for catching regressions, see `tests` folder. In VS, build
|
|
and run `glsl_optimizer_tests` project; in Xcode use `projects/xcode5/glsl_optimizer_tests`
|
|
project. The test executable requires path to the `tests` folder as an argument.
|
|
|
|
Each test comes as three text files; input, expected IR dump and expected optimized
|
|
GLSL dump.
|
|
|
|
If you're making changes to the project and want pull requests accepted easier, I'd
|
|
appreciate if there would be no test suite regressions. If you are implementing a
|
|
feature, it would be cool to add tests to cover it as well!
|
|
|
|
|
|
Notes
|
|
-----
|
|
|
|
* GLSL versions 1.10 and 1.20 are supported. 1.10 is the default, use #version 120 to specify
|
|
1.20.
|
|
* GLSL ES versions 1.00 and 3.00 are supported.
|
|
|
|
|
|
Dev Notes
|
|
---------
|
|
|
|
Pulling Mesa upstream:
|
|
|
|
git fetch upstream
|
|
git merge upstream/master
|
|
sh removeDeletedByUs.sh
|
|
# inspect files, git rm unneeded ones, fix conflicts etc.
|
|
# git commit
|
|
|
|
Rebuilding flex/bison parsers:
|
|
|
|
* When .y/.l files are changed, the parsers are *not* rebuilt automatically,
|
|
* Run ./generateParsers.sh to do that. You'll need bison & flex (on Mac, do "Install Command Line Tools" from Xcode)
|
|
* I use bison 2.3 and flex 2.5.35 (in OS X 10.8/10.9)
|
|
|