1 files changed, 371 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..059f127af
--- /dev/null
+++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp
@@ -0,0 +1,371 @@
+// 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"
+
+namespace GLShader {
+
+static bool IsPassThroughTevStage(const Pica::Regs::TevStageConfig& stage) {
+    return (stage.color_op == Pica::Regs::TevStageConfig::Operation::Replace &&
+        stage.alpha_op == Pica::Regs::TevStageConfig::Operation::Replace &&
+        stage.color_source1 == Pica::Regs::TevStageConfig::Source::Previous &&
+        stage.alpha_source1 == Pica::Regs::TevStageConfig::Source::Previous &&
+        stage.color_modifier1 == Pica::Regs::TevStageConfig::ColorModifier::SourceColor &&
+        stage.alpha_modifier1 == Pica::Regs::TevStageConfig::AlphaModifier::SourceAlpha &&
+        stage.GetColorMultiplier() == 1 &&
+        stage.GetAlphaMultiplier() == 1);
+}
+
+static void AppendSource(std::string& shader, Pica::Regs::TevStageConfig::Source source, const std::string& index_name) {
+    using Source = Pica::Regs::TevStageConfig::Source;
+    switch (source) {
+    case Source::PrimaryColor:
+        shader += "o[2]";
+        break;
+    case Source::PrimaryFragmentColor:
+        // HACK: Until we implement fragment lighting, use primary_color
+        shader += "o[2]";
+        break;
+    case Source::SecondaryFragmentColor:
+        // HACK: Until we implement fragment lighting, use zero
+        shader += "vec4(0.0, 0.0, 0.0, 0.0)";
+        break;
+    case Source::Texture0:
+        shader += "texture(tex[0], o[3].xy)";
+        break;
+    case Source::Texture1:
+        shader += "texture(tex[1], o[3].zw)";
+        break;
+    case Source::Texture2: // TODO: Unverified
+        shader += "texture(tex[2], o[5].zw)";
+        break;
+    case Source::PreviousBuffer:
+        shader += "g_combiner_buffer";
+        break;
+    case Source::Constant:
+        shader += "const_color[" + index_name + "]";
+        break;
+    case Source::Previous:
+        shader += "g_last_tex_env_out";
+        break;
+    default:
+        shader += "vec4(0.0)";
+        LOG_CRITICAL(Render_OpenGL, "Unknown source op %u", source);
+        break;
+    }
+}
+
+static void AppendColorModifier(std::string& shader, Pica::Regs::TevStageConfig::ColorModifier modifier,
+        Pica::Regs::TevStageConfig::Source source, const std::string& index_name) {
+    using ColorModifier = Pica::Regs::TevStageConfig::ColorModifier;
+    switch (modifier) {
+    case ColorModifier::SourceColor:
+        AppendSource(shader, source, index_name);
+        shader += ".rgb";
+        break;
+    case ColorModifier::OneMinusSourceColor:
+        shader += "vec3(1.0) - ";
+        AppendSource(shader, source, index_name);
+        shader += ".rgb";
+        break;
+    case ColorModifier::SourceAlpha:
+        AppendSource(shader, source, index_name);
+        shader += ".aaa";
+        break;
+    case ColorModifier::OneMinusSourceAlpha:
+        shader += "vec3(1.0) - ";
+        AppendSource(shader, source, index_name);
+        shader += ".aaa";
+        break;
+    case ColorModifier::SourceRed:
+        AppendSource(shader, source, index_name);
+        shader += ".rrr";
+        break;
+    case ColorModifier::OneMinusSourceRed:
+        shader += "vec3(1.0) - ";
+        AppendSource(shader, source, index_name);
+        shader += ".rrr";
+        break;
+    case ColorModifier::SourceGreen:
+        AppendSource(shader, source, index_name);
+        shader += ".ggg";
+        break;
+    case ColorModifier::OneMinusSourceGreen:
+        shader += "vec3(1.0) - ";
+        AppendSource(shader, source, index_name);
+        shader += ".ggg";
+        break;
+    case ColorModifier::SourceBlue:
+        AppendSource(shader, source, index_name);
+        shader += ".bbb";
+        break;
+    case ColorModifier::OneMinusSourceBlue:
+        shader += "vec3(1.0) - ";
+        AppendSource(shader, source, index_name);
+        shader += ".bbb";
+        break;
+    default:
+        shader += "vec3(0.0)";
+        LOG_CRITICAL(Render_OpenGL, "Unknown color modifier op %u", modifier);
+        break;
+    }
+}
+
+static void AppendAlphaModifier(std::string& shader, Pica::Regs::TevStageConfig::AlphaModifier modifier,
+        Pica::Regs::TevStageConfig::Source source, const std::string& index_name) {
+    using AlphaModifier = Pica::Regs::TevStageConfig::AlphaModifier;
+    switch (modifier) {
+    case AlphaModifier::SourceAlpha:
+        AppendSource(shader, source, index_name);
+        shader += ".a";
+        break;
+    case AlphaModifier::OneMinusSourceAlpha:
+        shader += "1.0 - ";
+        AppendSource(shader, source, index_name);
+        shader += ".a";
+        break;
+    case AlphaModifier::SourceRed:
+        AppendSource(shader, source, index_name);
+        shader += ".r";
+        break;
+    case AlphaModifier::OneMinusSourceRed:
+        shader += "1.0 - ";
+        AppendSource(shader, source, index_name);
+        shader += ".r";
+        break;
+    case AlphaModifier::SourceGreen:
+        AppendSource(shader, source, index_name);
+        shader += ".g";
+        break;
+    case AlphaModifier::OneMinusSourceGreen:
+        shader += "1.0 - ";
+        AppendSource(shader, source, index_name);
+        shader += ".g";
+        break;
+    case AlphaModifier::SourceBlue:
+        AppendSource(shader, source, index_name);
+        shader += ".b";
+        break;
+    case AlphaModifier::OneMinusSourceBlue:
+        shader += "1.0 - ";
+        AppendSource(shader, source, index_name);
+        shader += ".b";
+        break;
+    default:
+        shader += "vec3(0.0)";
+        LOG_CRITICAL(Render_OpenGL, "Unknown alpha modifier op %u", modifier);
+        break;
+    }
+}
+
+static void AppendColorCombiner(std::string& shader, Pica::Regs::TevStageConfig::Operation operation,
+        const std::string& variable_name) {
+    using Operation = Pica::Regs::TevStageConfig::Operation;
+
+    switch (operation) {
+    case Operation::Replace:
+        shader += variable_name + "[0]";
+        break;
+    case Operation::Modulate:
+        shader += variable_name + "[0] * " + variable_name + "[1]";
+        break;
+    case Operation::Add:
+        shader += "min(" + variable_name + "[0] + " + variable_name + "[1], vec3(1.0))";
+        break;
+    case Operation::AddSigned:
+        shader += "clamp(" + variable_name + "[0] + " + variable_name + "[1] - vec3(0.5), vec3(0.0), vec3(1.0))";
+        break;
+    case Operation::Lerp:
+        shader += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (vec3(1.0) - " + variable_name + "[2])";
+        break;
+    case Operation::Subtract:
+        shader += "max(" + variable_name + "[0] - " + variable_name + "[1], vec3(0.0))";
+        break;
+    case Operation::MultiplyThenAdd:
+        shader += "min(" + variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2], vec3(1.0))";
+        break;
+    case Operation::AddThenMultiply:
+        shader += "min(" + variable_name + "[0] + " + variable_name + "[1], vec3(1.0)) * " + variable_name + "[2]";
+        break;
+    default:
+        shader += "vec3(0.0)";
+        LOG_CRITICAL(Render_OpenGL, "Unknown color comb op %u", operation);
+        break;
+    }
+}
+
+static void AppendAlphaCombiner(std::string& shader, Pica::Regs::TevStageConfig::Operation operation,
+        const std::string& variable_name) {
+    using Operation = Pica::Regs::TevStageConfig::Operation;
+    switch (operation) {
+    case Operation::Replace:
+        shader += variable_name + "[0]";
+        break;
+    case Operation::Modulate:
+        shader += variable_name + "[0] * " + variable_name + "[1]";
+        break;
+    case Operation::Add:
+        shader += "min(" + variable_name + "[0] + " + variable_name + "[1], 1.0)";
+        break;
+    case Operation::AddSigned:
+        shader += "clamp(" + variable_name + "[0] + " + variable_name + "[1] - 0.5, 0.0, 1.0)";
+        break;
+    case Operation::Lerp:
+        shader += variable_name + "[0] * " + variable_name + "[2] + " + variable_name + "[1] * (1.0 - " + variable_name + "[2])";
+        break;
+    case Operation::Subtract:
+        shader += "max(" + variable_name + "[0] - " + variable_name + "[1], 0.0)";
+        break;
+    case Operation::MultiplyThenAdd:
+        shader += "min(" + variable_name + "[0] * " + variable_name + "[1] + " + variable_name + "[2], 1.0)";
+        break;
+    case Operation::AddThenMultiply:
+        shader += "min(" + variable_name + "[0] + " + variable_name + "[1], 1.0) * " + variable_name + "[2]";
+        break;
+    default:
+        shader += "0.0";
+        LOG_CRITICAL(Render_OpenGL, "Unknown alpha combiner op %u", operation);
+        break;
+    }
+}
+
+static void AppendAlphaTestCondition(std::string& shader, Pica::Regs::CompareFunc func) {
+    using CompareFunc = Pica::Regs::CompareFunc;
+    switch (func) {
+    case CompareFunc::Never:
+        shader += "true";
+        break;
+    case CompareFunc::Always:
+        shader += "false";
+        break;
+    case CompareFunc::Equal:
+        shader += "int(g_last_tex_env_out.a * 255.0f) != alphatest_ref";
+        break;
+    case CompareFunc::NotEqual:
+        shader += "int(g_last_tex_env_out.a * 255.0f) == alphatest_ref";
+        break;
+    case CompareFunc::LessThan:
+        shader += "int(g_last_tex_env_out.a * 255.0f) >= alphatest_ref";
+        break;
+    case CompareFunc::LessThanOrEqual:
+        shader += "int(g_last_tex_env_out.a * 255.0f) > alphatest_ref";
+        break;
+    case CompareFunc::GreaterThan:
+        shader += "int(g_last_tex_env_out.a * 255.0f) <= alphatest_ref";
+        break;
+    case CompareFunc::GreaterThanOrEqual:
+        shader += "int(g_last_tex_env_out.a * 255.0f) < alphatest_ref";
+        break;
+    default:
+        shader += "false";
+        LOG_CRITICAL(Render_OpenGL, "Unknown alpha test condition %u", func);
+        break;
+    }
+}
+
+std::string GenerateFragmentShader(const ShaderCacheKey& config) {
+    std::string shader = R"(
+#version 150 core
+
+#define NUM_VTX_ATTR 7
+#define NUM_TEV_STAGES 6
+
+in vec4 o[NUM_VTX_ATTR];
+out vec4 color;
+
+uniform int alphatest_ref;
+uniform vec4 const_color[NUM_TEV_STAGES];
+uniform sampler2D tex[3];
+
+uniform vec4 tev_combiner_buffer_color;
+
+void main(void) {
+vec4 g_combiner_buffer = tev_combiner_buffer_color;
+vec4 g_last_tex_env_out = vec4(0.0, 0.0, 0.0, 0.0);
+)";
+
+    // 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 == Pica::Regs::CompareFunc::Never) {
+        shader += "discard;";
+        return shader;
+    }
+
+    auto& tev_stages = config.tev_stages;
+    for (unsigned tev_stage_index = 0; tev_stage_index < tev_stages.size(); ++tev_stage_index) {
+        auto& tev_stage = tev_stages[tev_stage_index];
+        if (!IsPassThroughTevStage(tev_stage)) {
+            std::string index_name = std::to_string(tev_stage_index);
+
+            shader += "vec3 color_results_" + index_name + "[3] = vec3[3](";
+            AppendColorModifier(shader, tev_stage.color_modifier1, tev_stage.color_source1, index_name);
+            shader += ", ";
+            AppendColorModifier(shader, tev_stage.color_modifier2, tev_stage.color_source2, index_name);
+            shader += ", ";
+            AppendColorModifier(shader, tev_stage.color_modifier3, tev_stage.color_source3, index_name);
+            shader += ");\n";
+
+            shader += "vec3 color_output_" + index_name + " = ";
+            AppendColorCombiner(shader, tev_stage.color_op, "color_results_" + index_name);
+            shader += ";\n";
+
+            shader += "float alpha_results_" + index_name + "[3] = float[3](";
+            AppendAlphaModifier(shader, tev_stage.alpha_modifier1, tev_stage.alpha_source1, index_name);
+            shader += ", ";
+            AppendAlphaModifier(shader, tev_stage.alpha_modifier2, tev_stage.alpha_source2, index_name);
+            shader += ", ";
+            AppendAlphaModifier(shader, tev_stage.alpha_modifier3, tev_stage.alpha_source3, index_name);
+            shader += ");\n";
+
+            shader += "float alpha_output_" + index_name + " = ";
+            AppendAlphaCombiner(shader, tev_stage.alpha_op, "alpha_results_" + index_name);
+            shader += ";\n";
+
+            shader += "g_last_tex_env_out = vec4(min(color_output_" + index_name + " * " + std::to_string(tev_stage.GetColorMultiplier()) + ".0, 1.0), min(alpha_output_" + index_name + " * " + std::to_string(tev_stage.GetAlphaMultiplier()) + ".0, 1.0));\n";
+        }
+
+        if (config.TevStageUpdatesCombinerBufferColor(tev_stage_index))
+            shader += "g_combiner_buffer.rgb = g_last_tex_env_out.rgb;\n";
+
+        if (config.TevStageUpdatesCombinerBufferAlpha(tev_stage_index))
+            shader += "g_combiner_buffer.a = g_last_tex_env_out.a;\n";
+    }
+
+    if (config.alpha_test_func != Pica::Regs::CompareFunc::Always) {
+        shader += "if (";
+        AppendAlphaTestCondition(shader, config.alpha_test_func);
+        shader += ") {\n discard;\n }\n";
+    }
+
+    shader += "color = g_last_tex_env_out;\n}";
+    return shader;
+}
+
+std::string GenerateVertexShader() {
+    static const std::string shader_str = R"(
+#version 150 core
+
+#define NUM_VTX_ATTR 7
+
+in vec4 vert_position;
+in vec4 vert_color;
+in vec2 vert_texcoords0;
+in vec2 vert_texcoords1;
+in vec2 vert_texcoords2;
+
+out vec4 o[NUM_VTX_ATTR];
+
+void main() {
+    o[2] = vert_color;
+    o[3] = vec4(vert_texcoords0.xy, vert_texcoords1.xy);
+    o[5] = vec4(0.0, 0.0, vert_texcoords2.xy);
+
+    gl_Position = vec4(vert_position.x, -vert_position.y, -vert_position.z, vert_position.w);
+}
+)";
+    return shader_str;
+}
+
+} // namespace GLShaderGen