Ubershader: Add lighting shadergen override

include/config.hpp

@@ -20,6 +20,11 @@ struct EmulatorConfig {
 	bool discordRpcEnabled = false;
 	bool useUbershaders = ubershaderDefault;
 	bool accurateShaderMul = false;
+
+	// Toggles whether to force shadergen when there's more than N lights active and we're using the ubershader, for better performance
+	bool forceShadergenForLights = true;
+	int lightShadergenThreshold = 1;
+
 	RendererType rendererType = RendererType::OpenGL;
 	Audio::DSPCore::Type dspType = Audio::DSPCore::Type::Null;
 

include/renderer.hpp

@@ -20,6 +20,7 @@ enum class RendererType : s8 {
 	Software = 3,
 };
 
+struct EmulatorConfig;
 class GPU;
 struct SDL_Window;
 
@@ -46,6 +47,8 @@ class Renderer {
 	u32 outputWindowWidth = 400;
 	u32 outputWindowHeight = 240 * 2;
 
+	EmulatorConfig* emulatorConfig = nullptr;
+
   public:
 	Renderer(GPU& gpu, const std::array<u32, regNum>& internalRegs, const std::array<u32, extRegNum>& externalRegs);
 	virtual ~Renderer();
@@ -101,4 +104,6 @@ class Renderer {
 		outputWindowWidth = width;
 		outputWindowHeight = height;
 	}
+
+	void setConfig(EmulatorConfig* config) { emulatorConfig = config; }
 };

include/renderer_gl/renderer_gl.hpp

@@ -30,7 +30,7 @@ class RendererGL final : public Renderer {
 
 	OpenGL::VertexArray vao;
 	OpenGL::VertexBuffer vbo;
-	bool usingUbershader = true;
+	bool enableUbershader = true;
 
 	// Data 
 	struct {
@@ -110,7 +110,7 @@ class RendererGL final : public Renderer {
 	virtual std::string getUbershader() override;
 	virtual void setUbershader(const std::string& shader) override;
 
-	virtual void setUbershaderSetting(bool value) override { usingUbershader = value; }
+	virtual void setUbershaderSetting(bool value) override { enableUbershader = value; }
 	
 	std::optional<ColourBuffer> getColourBuffer(u32 addr, PICA::ColorFmt format, u32 width, u32 height, bool createIfnotFound = true);
 

src/config.cpp

@@ -64,6 +64,9 @@ void EmulatorConfig::load() {
 			vsyncEnabled = toml::find_or<toml::boolean>(gpu, "EnableVSync", true);
 			useUbershaders = toml::find_or<toml::boolean>(gpu, "UseUbershaders", ubershaderDefault);
 			accurateShaderMul = toml::find_or<toml::boolean>(gpu, "AccurateShaderMultiplication", false);
+
+			forceShadergenForLights = toml::find_or<toml::boolean>(gpu, "ForceShadergenForLighting", true);
+			lightShadergenThreshold = toml::find_or<toml::integer>(gpu, "ShadergenLightThreshold", 1);
 		}
 	}
 
@@ -130,6 +133,8 @@ void EmulatorConfig::save() {
 	data["GPU"]["EnableVSync"] = vsyncEnabled;
 	data["GPU"]["AccurateShaderMultiplication"] = accurateShaderMul;
 	data["GPU"]["UseUbershaders"] = useUbershaders;
+	data["GPU"]["ForceShadergenForLighting"] = forceShadergenForLights;
+	data["GPU"]["ShadergenLightThreshold"] = lightShadergenThreshold;
 
 	data["Audio"]["DSPEmulation"] = std::string(Audio::DSPCore::typeToString(dspType));
 	data["Audio"]["EnableAudio"] = audioEnabled;

src/core/PICA/gpu.cpp

@@ -58,6 +58,10 @@ GPU::GPU(Memory& mem, EmulatorConfig& config) : mem(mem), config(config) {
 			break;
 		}
 	}
+
+	if (renderer != nullptr) {
+		renderer->setConfig(&config);
+	}
 }
 
 void GPU::reset() {

src/core/renderer_gl/renderer_gl.cpp

@@ -4,6 +4,7 @@
 
 #include <cmrc/cmrc.hpp>
 
+#include "config.hpp"
 #include "PICA/float_types.hpp"
 #include "PICA/pica_frag_uniforms.hpp"
 #include "PICA/gpu.hpp"
@@ -383,6 +384,18 @@ void RendererGL::drawVertices(PICA::PrimType primType, std::span<const Vertex> v
 		OpenGL::Triangle,
 	};
 
+	bool usingUbershader = enableUbershader;
+	if (usingUbershader) {
+		const bool lightsEnabled = (regs[InternalRegs::LightingEnable] & 1) != 0;
+		const uint lightCount = (regs[InternalRegs::LightNumber] & 0x7) + 1;
+
+		// Emulating lights in the ubershader is incredibly slow, so we've got an option to render draws using moret han N lights via shadergen
+		// This way we generate fewer shaders overall than with full shadergen, but don't tank performance 
+		if (emulatorConfig->forceShadergenForLights && lightsEnabled && lightCount >= emulatorConfig->lightShadergenThreshold) {
+			usingUbershader = false;
+		}
+	}
+		
 	if (usingUbershader) {
 		gl.useProgram(triangleProgram);
 	} else {