Shaders

Shaders are represented in code by GLEngine::GLRenderer::Shaders::C_ShaderProgram class and can be loaded by GLEngine::GLRenderer::Shaders::C_ShaderManager. You can also load them by yourself, but then you lose most of the functions.

Shader definition

To define shader you have to define its a structure in XML format. Here is an example of how to define simple shader.

<?xml version="1.0" encoding="UTF-8"?>
<pipeline>
  <shader stage="vertex">basic/vertex.glsl</shader>
  <shader stage="fragment">basic/fragment.glsl</shader>
</pipeline>

Preprocess

Actual shader preprocessor supports two main features. Include file and macro definitions. It works pretty similarly to the C++ preprocessor. RegExes used to detect preprocessor directives are listed below. Include file looks for the file relative to the parsed *.glsl file, so you can easily find what is going on. Also, it doesn't work recursively right now (this means no #include inside of included file).

RegExes

  • Includes: ^(#include )"([^"]*)"$
  • Defines: ^(#define )([^\s]*)\s([^\s]+)$

Live reload

If you load shader program via C_ShaderManager and you are running in Debug configuration, you can live-edit your shader programmes. The shader program will be reloaded every one second. You can change its code and even its structure in XML.

Binding

Default binding is ascending from 0 - least often changed descriptor set down to most often changed descriptor sets. 0 - Frame constants 1 - Reserved 2 - Per draw call changes (effectively modelData) 3 - Materials (temp) 4 - Lights (temp)

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