include

Header Files

In the Surface Shader, there are several Lighting Models, such as standard, toon, etc.

At the same time, we have different Render Usages, such as render-to-scene, render-to-shadowmap, etc.

Different lighting models have different surface material data structures and lighting calculation functions, and there are subtle differences in the process between different render usages.

If we write code for different lighting models and different render usages independently, it will make the entire framework difficult to maintain.

Therefore, in the Surface Shader, we define the methods and structures for different lighting models with the same name in different header files, and then combine them using include.

In this way, it is easy to implement different lighting models under the same process by switching header files.

For example, in the following code, we import the definition of SurfacesMaterialData through #include <surfaces/data-structures/standard>. The structure used in the function is the PBR surface material data structure.

//PBR surface material
#include <surfaces/data-structures/standard>
#define CC_SURFACES_FRAGMENT_MODIFY_SHARED_DATA
void SurfacesFragmentModifySharedData(inout SurfacesMaterialData surfaceData)
{
    // set user-defined data to surfaceData
}

If we change its header file.

//toon surface material
#include <surfaces/data-structures/toon>
#define CC_SURFACES_FRAGMENT_MODIFY_SHARED_DATA
void SurfacesFragmentModifySharedData(inout SurfacesMaterialData surfaceData)
{
    // set user-defined data to surfaceData
}

At this time, the SurfacesMaterialData uses the structure defined in surfaces/data-structures/toon.

CCProgram

In the Surface Shader, the content of the CCProgram is purely GLSL code content. We can split the Shader into different CCProgram sections to form code snippets, and then reference them using include.

Take the following code as an example.

CCProgram shared-ubos %{
    ...
}%
CCProgram macro-remampping %{
    ...
}%

CCProgram vs %{
    #include<shared-ubos>
    #include<macro-remapping>
}%

CCProgram fs %{
    #include<shared-ubos>
    #include<macro-remapping>
}%

Note: When using include to reference code defined in CCProgram, it is limited to the same file only.