From f2e7f7e1019eeffc0aee438f788449fc4e0c118f Mon Sep 17 00:00:00 2001 From: bunnei Date: Tue, 6 Oct 2015 18:34:50 -0400 Subject: gl_rasterizer: Add documentation to ShaderCacheKey. --- src/video_core/renderer_opengl/gl_rasterizer.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/video_core') diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h index de9e4d22e..484579d82 100644 --- a/src/video_core/renderer_opengl/gl_rasterizer.h +++ b/src/video_core/renderer_opengl/gl_rasterizer.h @@ -17,6 +17,14 @@ #include "video_core/renderer_opengl/gl_state.h" #include "video_core/shader/shader_interpreter.h" +/** + * This struct contains all state used to generate the GLSL shader program that emulates the current + * Pica register configuration. This struct is used as a cache key for generated GLSL shader + * programs. The functions in gl_shader_gen.cpp should retrieve state from this struct only, not by + * directly accessing Pica registers. This should reduce the risk of bugs in shader generation where + * Pica state is not being captured in the shader cache key, thereby resulting in (what should be) + * two separate shaders sharing the same key. + */ struct ShaderCacheKey { using Regs = Pica::Regs; @@ -36,6 +44,11 @@ struct ShaderCacheKey { return (stage_index < 4) && ((combiner_buffer_input >> 4) & (1 << stage_index)); } + /** + * This function is used to construct a ShaderCacheKey with the current Pica register + * configuration. Don't construct a ShaderCacheKey manually, instead call this function (and + * extend it as additional state needs to be captured to generate shaders). + */ static ShaderCacheKey CurrentConfig() { const auto& regs = Pica::g_state.regs; ShaderCacheKey config; @@ -43,6 +56,9 @@ struct ShaderCacheKey { config.alpha_test_func = regs.output_merger.alpha_test.enable ? regs.output_merger.alpha_test.func.Value() : Pica::Regs::CompareFunc::Always; + // Copy relevant TevStageConfig fields only. We're doing this manually (instead of calling + // the GetTevStages() function) because BitField explicitly disables copies. + config.tev_stages[0].source_raw = regs.tev_stage0.source_raw; config.tev_stages[1].source_raw = regs.tev_stage1.source_raw; config.tev_stages[2].source_raw = regs.tev_stage2.source_raw; -- cgit v1.2.3