Question by Clement_Shimizu · Oct 03, 2013 at 11:50 PM · shaderlab glsl preprocessor pragma keywords

shaderlab preprocessor ignoring #if #endif when #pragma is within it.

I'm trying to figure out how to use preprocessor directives to specify target and glsl pragmas. The end goal for me is to be able to use shader keywords to enable and disable various parts of a shader, while maintaining the lowest "#pragma target" possible.
When i use the following code, the GLSL is defined weather or not USE_ADVANCED_OPTIONS is defined!

 #if USE_ADVANCED_OPTIONS
 #pragma glsl
 #endif

If you add that to a shader, and open up the compiled output, it is as if the preprocessor ignores the #if statement when dealing with pragma. Any idea on how to get beyond that?

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Clement_Shimizu · Oct 04, 2013 at 12:09 AM 0

I am wondering if #prama is being passed right through by the shader optimizer's preprocessor.

https://github.com/aras-p/glsl-optimizer/tree/master/src/glsl

1) lex and yacc-based preprocessor takes the inco$$anonymous$$g shader string

and produces a new string containing the preprocessed shader. This takes care of things like #if, #ifdef, #define, and preprocessor macro invocations. Note that #version, #extension, and some others are passed straight through. See glcpp/*"