diff options
Diffstat (limited to 'src/video_core/renderer_opengl/gl_shader_gen.cpp')
-rw-r--r-- | src/video_core/renderer_opengl/gl_shader_gen.cpp | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp new file mode 100644 index 000000000..d19d15e75 --- /dev/null +++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp @@ -0,0 +1,388 @@ +// Copyright 2015 Citra Emulator Project +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include "video_core/pica.h" +#include "video_core/renderer_opengl/gl_rasterizer.h" +#include "video_core/renderer_opengl/gl_shader_gen.h" + +using Pica::Regs; +using TevStageConfig = Regs::TevStageConfig; + +namespace GLShader { + +/// Detects if a TEV stage is configured to be skipped (to avoid generating unnecessary code) +static bool IsPassThroughTevStage(const TevStageConfig& stage) { + return (stage.color_op == TevStageConfig::Operation::Replace && + stage.alpha_op == TevStageConfig::Operation::Replace && + stage.color_source1 == TevStageConfig::Source::Previous && + stage.alpha_source1 == TevStageConfig::Source::Previous && + stage.color_modifier1 == TevStageConfig::ColorModifier::SourceColor && + stage.alpha_modifier1 == TevStageConfig::AlphaModifier::SourceAlpha && + stage.GetColorMultiplier() == 1 && + stage.GetAlphaMultiplier() == 1); +} + +/// Writes the specified TEV stage source component(s) +static void AppendSource(std::string& out, TevStageConfig::Source source, + const std::string& index_name) { + using Source = TevStageConfig::Source; + switch (source) { + case Source::PrimaryColor: + out += "primary_color"; + break; + case Source::PrimaryFragmentColor: + // HACK: Until we implement fragment lighting, use primary_color + out += "primary_color"; + break; + case Source::SecondaryFragmentColor: + // HACK: Until we implement fragment lighting, use zero + out += "vec4(0.0)"; + break; + case Source::Texture0: + out += "texture(tex[0], texcoord[0])"; + break; + case Source::Texture1: + out += "texture(tex[1], texcoord[1])"; + break; + case Source::Texture2: + out += "texture(tex[2], texcoord[2])"; + break; + case Source::PreviousBuffer: + out += "combiner_buffer"; + break; + case Source::Constant: + ((out += "const_color[") += index_name) += ']'; + break; + case Source::Previous: + out += "last_tex_env_out"; + break; + default: + out += "vec4(0.0)"; + LOG_CRITICAL(Render_OpenGL, "Unknown source op %u", source); + break; + } +} + +/// Writes the color components to use for the specified TEV stage color modifier +static void AppendColorModifier(std::string& out, TevStageConfig::ColorModifier modifier, + TevStageConfig::Source source, const std::string& index_name) { + using ColorModifier = TevStageConfig::ColorModifier; + switch (modifier) { + case ColorModifier::SourceColor: + AppendSource(out, source, index_name); + out += ".rgb"; + break; + case ColorModifier::OneMinusSourceColor: + out += "vec3(1.0) - "; + AppendSource(out, source, index_name); + out += ".rgb"; + break; + case ColorModifier::SourceAlpha: + AppendSource(out, source, index_name); + out += ".aaa"; + break; + case ColorModifier::OneMinusSourceAlpha: + out += "vec3(1.0) - "; + AppendSource(out, source, index_name); + out += ".aaa"; + break; + case ColorModifier::SourceRed: + AppendSource(out, source, index_name); + out += ".rrr"; + break; + case ColorModifier::OneMinusSourceRed: + out += "vec3(1.0) - "; + AppendSource(out, source, index_name); + out += ".rrr"; + break; + case ColorModifier::SourceGreen: + AppendSource(out, source, index_name); + out += ".ggg"; + break; + case ColorModifier::OneMinusSourceGreen: + out += "vec3(1.0) - "; + AppendSource(out, source, index_name); + out += ".ggg"; + break; + case ColorModifier::SourceBlue: + AppendSource(out, source, index_name); + out += ".bbb"; + break; + case ColorModifier::OneMinusSourceBlue: + out += "vec3(1.0) - "; + AppendSource(out, source, index_name); + out += ".bbb"; + break; + default: + out += "vec3(0.0)"; + LOG_CRITICAL(Render_OpenGL, "Unknown color modifier op %u", modifier); + break; + } +} + +/// Writes the alpha component to use for the specified TEV stage alpha modifier +static void AppendAlphaModifier(std::string& out, TevStageConfig::AlphaModifier modifier, + TevStageConfig::Source source, const std::string& index_name) { + using AlphaModifier = TevStageConfig::AlphaModifier; + switch (modifier) { + case AlphaModifier::SourceAlpha: + AppendSource(out, source, index_name); + out += ".a"; + break; + case AlphaModifier::OneMinusSourceAlpha: + out += "1.0 - "; + AppendSource(out, source, index_name); + out += ".a"; + break; + case AlphaModifier::SourceRed: + AppendSource(out, source, index_name); + out += ".r"; + break; + case AlphaModifier::OneMinusSourceRed: + out += "1.0 - "; + AppendSource(out, source, index_name); + out += ".r"; + break; + case AlphaModifier::SourceGreen: + AppendSource(out, source, index_name); + out += ".g"; + break; + case AlphaModifier::OneMinusSourceGreen: + out += "1.0 - "; + AppendSource(out, source, index_name); + out += ".g"; + break; + case AlphaModifier::SourceBlue: + AppendSource(out, source, index_name); + out += ".b"; + break; + case AlphaModifier::OneMinusSourceBlue: + out += "1.0 - "; + AppendSource(out, source, index_name); + out += ".b"; + break; + default: + out += "0.0"; + LOG_CRITICAL(Render_OpenGL, "Unknown alpha modifier op %u", modifier); + break; + } +} + +/// Writes the combiner function for the color components for the specified TEV stage operation +static void AppendColorCombiner(std::string& out, TevStageConfig::Operation operation, + const std::string& variable_name) { + out += "clamp("; + using Operation = TevStageConfig::Operation; + switch (operation) { + case Operation::Replace: + out += variable_name + "[0]"; + break; + case Operation::Modulate: + out += variable_name + "[0] * " + variable_name + "[1]"; + break; + case Operation::Add: + out += variable_name + "[0] + " + variable_name + "[1]"; + break; + case Operation::AddSigned: + out += variable_name + "[0] + " + variable_name + "[1] - vec3(0.5)"; + break; + case Operation::Lerp: + // TODO(bunnei): Verify if HW actually does this per-component, otherwise we can just use builtin lerp + out += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (vec3(1.0) - " + variable_name + "[2])"; + break; + case Operation::Subtract: + out += variable_name + "[0] - " + variable_name + "[1]"; + break; + case Operation::MultiplyThenAdd: + out += variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2]"; + break; + case Operation::AddThenMultiply: + out += "min(" + variable_name + "[0] + " + variable_name + "[1], vec3(1.0)) * " + variable_name + "[2]"; + break; + default: + out += "vec3(0.0)"; + LOG_CRITICAL(Render_OpenGL, "Unknown color combiner operation: %u", operation); + break; + } + out += ", vec3(0.0), vec3(1.0))"; // Clamp result to 0.0, 1.0 +} + +/// Writes the combiner function for the alpha component for the specified TEV stage operation +static void AppendAlphaCombiner(std::string& out, TevStageConfig::Operation operation, + const std::string& variable_name) { + out += "clamp("; + using Operation = TevStageConfig::Operation; + switch (operation) { + case Operation::Replace: + out += variable_name + "[0]"; + break; + case Operation::Modulate: + out += variable_name + "[0] * " + variable_name + "[1]"; + break; + case Operation::Add: + out += variable_name + "[0] + " + variable_name + "[1]"; + break; + case Operation::AddSigned: + out += variable_name + "[0] + " + variable_name + "[1] - 0.5"; + break; + case Operation::Lerp: + out += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (1.0 - " + variable_name + "[2])"; + break; + case Operation::Subtract: + out += variable_name + "[0] - " + variable_name + "[1]"; + break; + case Operation::MultiplyThenAdd: + out += variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2]"; + break; + case Operation::AddThenMultiply: + out += "min(" + variable_name + "[0] + " + variable_name + "[1], 1.0) * " + variable_name + "[2]"; + break; + default: + out += "0.0"; + LOG_CRITICAL(Render_OpenGL, "Unknown alpha combiner operation: %u", operation); + break; + } + out += ", 0.0, 1.0)"; +} + +/// Writes the if-statement condition used to evaluate alpha testing +static void AppendAlphaTestCondition(std::string& out, Regs::CompareFunc func) { + using CompareFunc = Regs::CompareFunc; + switch (func) { + case CompareFunc::Never: + out += "true"; + break; + case CompareFunc::Always: + out += "false"; + break; + case CompareFunc::Equal: + case CompareFunc::NotEqual: + case CompareFunc::LessThan: + case CompareFunc::LessThanOrEqual: + case CompareFunc::GreaterThan: + case CompareFunc::GreaterThanOrEqual: + { + static const char* op[] = { "!=", "==", ">=", ">", "<=", "<", }; + unsigned index = (unsigned)func - (unsigned)CompareFunc::Equal; + out += "int(last_tex_env_out.a * 255.0f) " + std::string(op[index]) + " alphatest_ref"; + break; + } + + default: + out += "false"; + LOG_CRITICAL(Render_OpenGL, "Unknown alpha test condition %u", func); + break; + } +} + +/// Writes the code to emulate the specified TEV stage +static void WriteTevStage(std::string& out, const PicaShaderConfig& config, unsigned index) { + auto& stage = config.tev_stages[index]; + if (!IsPassThroughTevStage(stage)) { + std::string index_name = std::to_string(index); + + out += "vec3 color_results_" + index_name + "[3] = vec3[3]("; + AppendColorModifier(out, stage.color_modifier1, stage.color_source1, index_name); + out += ", "; + AppendColorModifier(out, stage.color_modifier2, stage.color_source2, index_name); + out += ", "; + AppendColorModifier(out, stage.color_modifier3, stage.color_source3, index_name); + out += ");\n"; + + out += "vec3 color_output_" + index_name + " = "; + AppendColorCombiner(out, stage.color_op, "color_results_" + index_name); + out += ";\n"; + + out += "float alpha_results_" + index_name + "[3] = float[3]("; + AppendAlphaModifier(out, stage.alpha_modifier1, stage.alpha_source1, index_name); + out += ", "; + AppendAlphaModifier(out, stage.alpha_modifier2, stage.alpha_source2, index_name); + out += ", "; + AppendAlphaModifier(out, stage.alpha_modifier3, stage.alpha_source3, index_name); + out += ");\n"; + + out += "float alpha_output_" + index_name + " = "; + AppendAlphaCombiner(out, stage.alpha_op, "alpha_results_" + index_name); + out += ";\n"; + + out += "last_tex_env_out = vec4(" + "clamp(color_output_" + index_name + " * " + std::to_string(stage.GetColorMultiplier()) + ".0, vec3(0.0), vec3(1.0))," + "clamp(alpha_output_" + index_name + " * " + std::to_string(stage.GetAlphaMultiplier()) + ".0, 0.0, 1.0));\n"; + } + + if (config.TevStageUpdatesCombinerBufferColor(index)) + out += "combiner_buffer.rgb = last_tex_env_out.rgb;\n"; + + if (config.TevStageUpdatesCombinerBufferAlpha(index)) + out += "combiner_buffer.a = last_tex_env_out.a;\n"; +} + +std::string GenerateFragmentShader(const PicaShaderConfig& config) { + std::string out = R"( +#version 330 +#extension GL_ARB_explicit_uniform_location : require + +#define NUM_TEV_STAGES 6 + +in vec4 primary_color; +in vec2 texcoord[3]; + +out vec4 color; +)"; + + using Uniform = RasterizerOpenGL::PicaShader::Uniform; + out += "layout(location = " + std::to_string((int)Uniform::AlphaTestRef) + ") uniform int alphatest_ref;\n"; + out += "layout(location = " + std::to_string((int)Uniform::TevConstColors) + ") uniform vec4 const_color[NUM_TEV_STAGES];\n"; + out += "layout(location = " + std::to_string((int)Uniform::Texture0) + ") uniform sampler2D tex[3];\n"; + out += "layout(location = " + std::to_string((int)Uniform::TevCombinerBufferColor) + ") uniform vec4 tev_combiner_buffer_color;\n"; + + out += "void main() {\n"; + out += "vec4 combiner_buffer = tev_combiner_buffer_color;\n"; + out += "vec4 last_tex_env_out = vec4(0.0);\n"; + + // Do not do any sort of processing if it's obvious we're not going to pass the alpha test + if (config.alpha_test_func == Regs::CompareFunc::Never) { + out += "discard; }"; + return out; + } + + for (size_t index = 0; index < config.tev_stages.size(); ++index) + WriteTevStage(out, config, (unsigned)index); + + if (config.alpha_test_func != Regs::CompareFunc::Always) { + out += "if ("; + AppendAlphaTestCondition(out, config.alpha_test_func); + out += ") discard;\n"; + } + + out += "color = last_tex_env_out;\n}"; + + return out; +} + +std::string GenerateVertexShader() { + std::string out = "#version 330\n"; + out += "layout(location = " + std::to_string((int)ATTRIBUTE_POSITION) + ") in vec4 vert_position;\n"; + out += "layout(location = " + std::to_string((int)ATTRIBUTE_COLOR) + ") in vec4 vert_color;\n"; + out += "layout(location = " + std::to_string((int)ATTRIBUTE_TEXCOORD0) + ") in vec2 vert_texcoord0;\n"; + out += "layout(location = " + std::to_string((int)ATTRIBUTE_TEXCOORD1) + ") in vec2 vert_texcoord1;\n"; + out += "layout(location = " + std::to_string((int)ATTRIBUTE_TEXCOORD2) + ") in vec2 vert_texcoord2;\n"; + + out += R"( +out vec4 primary_color; +out vec2 texcoord[3]; + +void main() { + primary_color = vert_color; + texcoord[0] = vert_texcoord0; + texcoord[1] = vert_texcoord1; + texcoord[2] = vert_texcoord2; + gl_Position = vec4(vert_position.x, -vert_position.y, -vert_position.z, vert_position.w); +} +)"; + + return out; +} + +} // namespace GLShader |