ShaderGenerator

class ShaderGenerator

Bases: TypedReferenceCount

The ShaderGenerator is a device that effectively replaces the classic fixed function pipeline with a ‘next-gen’ fixed function pipeline. The next-gen fixed function pipeline supports features like normal mapping, gloss mapping, cartoon lighting, and so forth. It works by automatically generating a shader from a given RenderState.

Currently, there is one ShaderGenerator object per GraphicsStateGuardian. It is our intent that in time, people will write classes that derive from ShaderGenerator but which yield slightly different results.

The ShaderGenerator owes its existence to the ‘Bamboo Team’ at Carnegie Mellon’s Entertainment Technology Center. This is a group of students who, as a semester project, decided that next-gen graphics should be accessible to everyone, even if they don’t know shader programming. The group consisted of:

Aaron Lo, Programmer Heegun Lee, Programmer Erin Fernandez, Artist/Tester Joe Grubb, Artist/Tester Ivan Ortega, Technical Artist/Tester

Thanks to them!

Inheritance diagram

ShaderGenerator(GraphicsStateGuardianBase const *gsg)

ShaderGenerator(ShaderGenerator const&) = default

Create a ShaderGenerator. This has no state, except possibly to cache certain results. The given parameters contain information about the capabilities of the target for which the shader will be compiled.

Create a ShaderGenerator. This has no state, except possibly to cache certain results. The parameter that must be passed is the GSG to which the shader generator belongs.

void clear_generated_shaders(void)

Removes all previously generated shaders, requiring all shaders to be regenerated. Does not clear cache of compiled shaders.

New in version 1.10.0.

static TypeHandle get_class_type(void)

void rehash_generated_shaders(void)

Rehashes all the states with generated shaders, removing the ones that are no longer fresh.

Call this if certain state has changed in such a way as to require a rerun of the shader generator. This should be rare because in most cases, the shader generator will automatically regenerate shaders as necessary.

New in version 1.10.0.

virtual ConstPointerTo<ShaderAttrib> synthesize_shader(RenderState const *rs, GeomVertexAnimationSpec const &anim)

This is the routine that implements the next-gen fixed function pipeline by synthesizing a shader. It also takes care of setting up any buffers needed to produce the requested effects.

Currently supports: - flat colors - vertex colors - lighting - normal maps, even multiple - gloss maps, but not multiple - glow maps, but not multiple - materials, but not updates to materials - 2D textures - all texture stage modes, including combine modes - color scale attrib - light ramps (for cartoon shading) - shadow mapping - most texgen modes - texmatrix - 1D/2D/3D textures, cube textures, 2D tex arrays - linear/exp/exp2 fog - animation

Potential optimizations - omit attenuation calculations if attenuation off