From ccf9693877a649ccb9c2b891b37b36b54d04ffbb Mon Sep 17 00:00:00 2001
From: wheremyfoodat <44909372+wheremyfoodat@users.noreply.github.com>
Date: Thu, 18 Jul 2024 02:57:41 +0300
Subject: [PATCH] Shadergen: More lighting work

---
 include/PICA/pica_frag_uniforms.hpp  | 23 ++++++++++++++++++-
 include/PICA/shader_gen.hpp          |  1 +
 src/core/PICA/shader_gen_glsl.cpp    | 34 ++++++++++++++++++++++++----
 src/core/renderer_gl/renderer_gl.cpp |  4 ++++
 4 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/include/PICA/pica_frag_uniforms.hpp b/include/PICA/pica_frag_uniforms.hpp
index 332acd4e..0122ae93 100644
--- a/include/PICA/pica_frag_uniforms.hpp
+++ b/include/PICA/pica_frag_uniforms.hpp
@@ -1,12 +1,27 @@
 #pragma once
 #include <array>
+#include <cstddef>
 #include <type_traits>
 
 #include "helpers.hpp"
 
 namespace PICA {
-	struct FragmentUniforms {
+	struct LightUniform {
 		using vec3 = std::array<float, 3>;
+
+		// std140 requires vec3s be aligned to 16 bytes
+		alignas(16) vec3 specular0;
+		alignas(16) vec3 specular1;
+		alignas(16) vec3 diffuse;
+		alignas(16) vec3 ambient;
+		alignas(16) vec3 position;
+		alignas(16) vec3 spotlightDirection;
+		
+		float distAttenuationBias;
+		float distanceAttenuationScale;
+	};
+
+	struct FragmentUniforms {
 		using vec4 = std::array<float, 4>;
 		static constexpr usize tevStageCount = 6;
 
@@ -17,5 +32,11 @@ namespace PICA {
 		alignas(16) vec4 constantColors[tevStageCount];
 		alignas(16) vec4 tevBufferColor;
 		alignas(16) vec4 clipCoords;
+
+		// NOTE: THIS MUST BE LAST so that if lighting is disabled we can potentially omit uploading it
+		LightUniform lightUniforms[8];
 	};
+
+	// Assert that lightUniforms is the last member of the structure
+	static_assert(offsetof(FragmentUniforms, lightUniforms) + 8 * sizeof(LightUniform) == sizeof(FragmentUniforms));
 }  // namespace PICA
\ No newline at end of file
diff --git a/include/PICA/shader_gen.hpp b/include/PICA/shader_gen.hpp
index 0a6bca8e..21d85d98 100644
--- a/include/PICA/shader_gen.hpp
+++ b/include/PICA/shader_gen.hpp
@@ -26,6 +26,7 @@ namespace PICA::ShaderGen {
 		void getAlphaOperation(std::string& shader, PICA::TexEnvConfig::Operation op);
 
 		void applyAlphaTest(std::string& shader, const PICARegs& regs);
+		void compileLights(std::string& shader, const PICA::FragmentConfig& config);
 
 		u32 textureConfig = 0;
 
diff --git a/src/core/PICA/shader_gen_glsl.cpp b/src/core/PICA/shader_gen_glsl.cpp
index 5dbc3b81..9c319780 100644
--- a/src/core/PICA/shader_gen_glsl.cpp
+++ b/src/core/PICA/shader_gen_glsl.cpp
@@ -3,6 +3,17 @@ using namespace PICA;
 using namespace PICA::ShaderGen;
 
 static constexpr const char* uniformDefinition = R"(
+	struct LightSource {
+		vec3 specular0;
+		vec3 specular1;
+		vec3 diffuse;
+		vec3 ambient;
+		vec3 position;
+		vec3 spotlightDirection;
+		float distanceAttenuationBias;
+		float distanceAttenuationScale;
+	};
+
 	layout(std140) uniform FragmentUniforms {
 		int alphaReference;
 		float depthScale;
@@ -11,6 +22,8 @@ static constexpr const char* uniformDefinition = R"(
 		vec4 constantColors[6];
 		vec4 tevBufferColor;
 		vec4 clipCoords;
+
+		LightSource lightSources[8];
 	};
 )";
 
@@ -128,7 +141,7 @@ std::string FragmentGenerator::generate(const PICARegs& regs, const FragmentConf
 		uniform sampler2D u_tex2;
 		// GLES doesn't support sampler1DArray, as such we'll have to change how we handle lighting later
 #ifndef USING_GLES
-		uniform sampler1DArray u_tex_lighting_lut;
+		uniform sampler2D u_tex_lighting_lut;
 #endif
 	)";
 
@@ -140,9 +153,14 @@ std::string FragmentGenerator::generate(const PICARegs& regs, const FragmentConf
 		void main() {
 			vec4 combinerOutput = v_colour;
 			vec4 previousBuffer = vec4(0.0);
-			vec4 tevNextPreviousBuffer = tevBufferColor;			
+			vec4 tevNextPreviousBuffer = tevBufferColor;	
+
+			vec4 primaryColor = vec4(0.0);
+			vec4 secondaryColor = vec4(0.0);		
 	)";
 
+	compileLights(ret, config);
+
 	ret += R"(
 		vec3 colorOp1 = vec3(0.0);
 		vec3 colorOp2 = vec3(0.0);
@@ -353,8 +371,8 @@ void FragmentGenerator::getSource(std::string& shader, TexEnvConfig::Source sour
 		case TexEnvConfig::Source::PreviousBuffer: shader += "previousBuffer"; break;
 		
 		// Lighting
-		case TexEnvConfig::Source::PrimaryFragmentColor:
-		case TexEnvConfig::Source::SecondaryFragmentColor: shader += "vec4(1.0, 1.0, 1.0, 1.0)"; break;
+		case TexEnvConfig::Source::PrimaryFragmentColor: shader += "primaryColor"; break;
+		case TexEnvConfig::Source::SecondaryFragmentColor: shader += "secondaryColor"; break;
 
 		default:
 			Helpers::warn("Unimplemented TEV source: %d", static_cast<int>(source));
@@ -430,3 +448,11 @@ void FragmentGenerator::applyAlphaTest(std::string& shader, const PICARegs& regs
 
 	shader += ") { discard; }\n";
 }
+
+void FragmentGenerator::compileLights(std::string& shader, const PICA::FragmentConfig& config) {
+	if (!config.lighting.enable) {
+		return;
+	}
+
+
+}
\ No newline at end of file
diff --git a/src/core/renderer_gl/renderer_gl.cpp b/src/core/renderer_gl/renderer_gl.cpp
index b85e7689..34ed0d22 100644
--- a/src/core/renderer_gl/renderer_gl.cpp
+++ b/src/core/renderer_gl/renderer_gl.cpp
@@ -875,6 +875,10 @@ OpenGL::Program& RendererGL::getSpecializedShader() {
 		vec[3] = float((color >> 24) & 0xFF) / 255.0f;
 	}
 
+	// Append lighting uniforms
+	if (fsConfig.lighting.enable) {
+	}
+
 	gl.bindUBO(programEntry.uboBinding);
 	glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(PICA::FragmentUniforms), &uniforms);