Loads a shader used for modifying render targets, as such it only contains a pixel shader, the vertex shader is automatically generated to make sure it applies to the full screen. This type of shader should only be applied to objects created with CreateObjectQuad but nothing bad will happen if you choose to apply it to other objects, it will just produce unusual rendering results for that object. Currently shaders default to GLSL version 1.10, the line "#version 110" will be automatically added as the first line of the shader unless you specify a "#version " line of your own. Note that doing this may mean your shader does not work on all devices and platforms. The global "precision" value will be added and should not be included in the shader source. Returns an ID that can be used to reference this shader in other commands. IDs are shared across all shader types so loading a full screen shader into ID 1 will not work if a normal shader exists with ID 1.
integer LoadFullScreenShader( szPixelFile )
LoadFullScreenShader( shaderID, szPixelFile )