TEV definitions for shader generator

include/PICA/regs.hpp

@@ -344,4 +344,108 @@ namespace PICA {
 		GeometryPrimitive = 3,
 	};
 
+	struct TexEnvConfig {
+		enum class Source : u8 {
+			PrimaryColor = 0x0,
+			PrimaryFragmentColor = 0x1,
+			SecondaryFragmentColor = 0x2,
+			Texture0 = 0x3,
+			Texture1 = 0x4,
+			Texture2 = 0x5,
+			Texture3 = 0x6,
+			// TODO: Inbetween values are unknown
+			PreviousBuffer = 0xD,
+			Constant = 0xE,
+			Previous = 0xF,
+		};
+
+		enum class ColorOperand : u8 {
+			SourceColor = 0x0,
+			OneMinusSourceColor = 0x1,
+			SourceAlpha = 0x2,
+			OneMinusSourceAlpha = 0x3,
+			SourceRed = 0x4,
+			OneMinusSourceRed = 0x5,
+			// TODO: Inbetween values are unknown
+			SourceGreen = 0x8,
+			OneMinusSourceGreen = 0x9,
+			// Inbetween values are unknown
+			SourceBlue = 0xC,
+			OneMinusSourceBlue = 0xD,
+		};
+
+		enum class AlphaOperand : u8 {
+			SourceAlpha = 0x0,
+			OneMinusSourceAlpha = 0x1,
+			SourceRed = 0x2,
+			OneMinusSourceRed = 0x3,
+			SourceGreen = 0x4,
+			OneMinusSourceGreen = 0x5,
+			SourceBlue = 0x6,
+			OneMinusSourceBlue = 0x7,
+		};
+
+		enum class Operation : u8 {
+			Replace = 0,
+			Modulate = 1,
+			Add = 2,
+			AddSigned = 3,
+			Lerp = 4,
+			Subtract = 5,
+			Dot3RGB = 6,
+			Dot3RGBA = 7,
+			MultiplyAdd = 8,
+			AddMultiply = 9,
+		};
+
+		// RGB sources
+		Source colorSource1, colorSource2, colorSource3;
+		// Alpha sources
+		Source alphaSource1, alphaSource2, alphaSource3;
+
+		// RGB operands
+		ColorOperand colorOperand1, colorOperand2, colorOperand3;
+		// Alpha operands
+		AlphaOperand alphaOperand1, alphaOperand2, alphaOperand3;
+
+		// Texture environment operations for this stage
+		Operation colorOp, alphaOp;
+
+		u32 constColor;
+
+	  private:
+		// These are the only private members since their value doesn't actually reflect the scale
+		// So we make them public so we'll always use the appropriate member functions instead
+		u8 colorScale;
+		u8 alphaScale;
+
+	  public:
+		// Create texture environment object from TEV registers
+		TexEnvConfig(u32 source, u32 operand, u32 combiner, u32 color, u32 scale) : constColor(color) {
+			colorSource1 = Helpers::getBits<0, 4, Source>(source);
+			colorSource2 = Helpers::getBits<4, 4, Source>(source);
+			colorSource3 = Helpers::getBits<8, 4, Source>(source);
+
+			alphaSource1 = Helpers::getBits<16, 4, Source>(source);
+			alphaSource2 = Helpers::getBits<20, 4, Source>(source);
+			alphaSource3 = Helpers::getBits<24, 4, Source>(source);
+
+			colorOperand1 = Helpers::getBits<0, 4, ColorOperand>(operand);
+			colorOperand2 = Helpers::getBits<4, 4, ColorOperand>(operand);
+			colorOperand3 = Helpers::getBits<8, 4, ColorOperand>(operand);
+
+			alphaOperand1 = Helpers::getBits<12, 3, AlphaOperand>(operand);
+			alphaOperand2 = Helpers::getBits<16, 3, AlphaOperand>(operand);
+			alphaOperand3 = Helpers::getBits<20, 3, AlphaOperand>(operand);
+
+			colorOp = Helpers::getBits<0, 4, Operation>(combiner);
+			alphaOp = Helpers::getBits<16, 4, Operation>(combiner);
+
+			colorScale = Helpers::getBits<0, 2>(scale);
+			alphaScale = Helpers::getBits<16, 2>(scale);
+		}
+
+		u32 getColorScale() { return (colorScale <= 2) ? (1 << colorScale) : 1; }
+		u32 getAlphaScale() { return (alphaScale <= 2) ? (1 << alphaScale) : 1; }
+	};
 }  // namespace PICA

include/PICA/shader_gen.hpp

@@ -17,6 +17,8 @@ namespace PICA::ShaderGen {
 		API api;
 		Language language;
 
+		void compileTEV(std::string& shader, int stage, const PICARegs& regs);
+
 	  public:
 		FragmentGenerator(API api, Language language) : api(api), language(language) {}
 		std::string generate(const PICARegs& regs);

include/renderer_gl/renderer_gl.hpp

@@ -6,6 +6,7 @@
 #include "PICA/float_types.hpp"
 #include "PICA/pica_vertex.hpp"
 #include "PICA/regs.hpp"
+#include "PICA/shader_gen.hpp"
 #include "gl_state.hpp"
 #include "helpers.hpp"
 #include "logger.hpp"
@@ -60,6 +61,8 @@ class RendererGL final : public Renderer {
 	OpenGL::Framebuffer getColourFBO();
 	OpenGL::Texture getTexture(Texture& tex);
 
+	PICA::ShaderGen::FragmentGenerator fragShaderGen;
+
 	MAKE_LOG_FUNCTION(log, rendererLogger)
 	void setupBlending();
 	void setupStencilTest(bool stencilEnable);
@@ -71,7 +74,7 @@ class RendererGL final : public Renderer {
 
   public:
 	RendererGL(GPU& gpu, const std::array<u32, regNum>& internalRegs, const std::array<u32, extRegNum>& externalRegs)
-		: Renderer(gpu, internalRegs, externalRegs) {}
+		: Renderer(gpu, internalRegs, externalRegs), fragShaderGen(PICA::ShaderGen::API::GL, PICA::ShaderGen::Language::GLSL) {}
 	~RendererGL() override;
 
 	void reset() override;

src/core/PICA/shader_gen_glsl.cpp

@@ -1,4 +1,5 @@
 #include "PICA/shader_gen.hpp"
+using namespace PICA;
 using namespace PICA::ShaderGen;
 
 std::string FragmentGenerator::generate(const PICARegs& regs) {
@@ -10,6 +11,8 @@ std::string FragmentGenerator::generate(const PICARegs& regs) {
 		default: break;
 	}
 
+	bool unimplementedFlag = false;
+
 	// Input and output attributes
 	ret += R"(
 		in vec3 v_tangent;
@@ -24,7 +27,45 @@ std::string FragmentGenerator::generate(const PICARegs& regs) {
 		flat in vec4 v_textureEnvBufferColor;
 
 		out vec4 fragColour;
+		uniform sampler2D u_tex0;
+		uniform sampler2D u_tex1;
+		uniform sampler2D u_tex2;
+		uniform sampler1DArray u_tex_lighting_lut;
+
+		vec4 tevSources[16];
+		vec4 tevNextPreviousBuffer;
+
+		vec3 regToColor(uint reg) {
+			// Normalization scale to convert from [0...255] to [0.0...1.0]
+			const float scale = 1.0 / 255.0;
+
+			return scale * vec3(float(bitfieldExtract(reg, 20, 8)), float(bitfieldExtract(reg, 10, 8)), float(bitfieldExtract(reg, 00, 8)));
+		}
 	)";
 
+	// Emit main function for fragment shader
+	// When not initialized, source 13 is set to vec4(0.0) and 15 is set to the vertex colour
+	ret += R"(
+		void main() {
+			tevSources[0] = v_colour;
+			tevSources[13] = vec4(0.0);  // Previous buffer colour 
+			tevSources[15] = v_colour;   // Previous combiner
+	)";
+
+	for (int i = 0; i < 6; i++) {
+		compileTEV(ret, i, regs);
+	}
+
 	return ret;
+}
+
+void FragmentGenerator::compileTEV(std::string& shader, int stage, const PICARegs& regs) {
+	// Base address for each TEV stage's configuration
+	static constexpr std::array<u32, 6> ioBases = {
+		InternalRegs::TexEnv0Source, InternalRegs::TexEnv1Source, InternalRegs::TexEnv2Source,
+		InternalRegs::TexEnv3Source, InternalRegs::TexEnv4Source, InternalRegs::TexEnv5Source,
+	};
+
+	const u32 ioBase = ioBases[stage];
+	TexEnvConfig tev(regs[ioBase], regs[ioBase + 1], regs[ioBase + 2], regs[ioBase + 3], regs[ioBase + 4]);
 }

src/core/renderer_gl/renderer_gl.cpp

@@ -388,6 +388,7 @@ void RendererGL::drawVertices(PICA::PrimType primType, std::span<const Vertex> v
 		OpenGL::TriangleFan,
 		OpenGL::Triangle,
 	};
+	std::cout << fragShaderGen.generate(regs);
 
 	const auto primitiveTopology = primTypes[static_cast<usize>(primType)];
 	gl.disableScissor();