Clean up graphics context code

include/PICA/gpu.hpp

@@ -110,7 +110,6 @@ class GPU {
 	void deinitGraphicsContext() { renderer->deinitGraphicsContext(); }
 
 	void initGraphicsContext(void* window) { renderer->initGraphicsContext(window); }
-	void initGraphicsContext(GL::Context* context) { renderer->initGraphicsContext(context); }
 
 	void fireDMA(u32 dest, u32 source, u32 size);
 	void reset();

include/emulator.hpp

@@ -106,11 +106,8 @@ class Emulator {
 	bool loadELF(const std::filesystem::path& path);
 	bool loadELF(std::ifstream& file);
 
-#ifdef PANDA3DS_FRONTEND_QT
-	// For passing the GL context from Qt to the renderer
-	void initGraphicsContext(GL::Context* glContext) { gpu.initGraphicsContext(glContext); }
-	void initGraphicsContext(void* window) { gpu.initGraphicsContext(window); }
-#endif
+	// For passing the SDL Window, GL context, etc from the frontend to the renderer
+	void initGraphicsContext(void* context) { gpu.initGraphicsContext(context); }
 
 	RomFS::DumpingResult dumpRomFS(const std::filesystem::path& path);
 	void setOutputSize(u32 width, u32 height) { gpu.setOutputSize(width, height); }

include/panda_qt/main_window.hpp

@@ -136,7 +136,7 @@ class MainWindow : public QMainWindow {
 	void loadKeybindings();
 	void saveKeybindings();
 
-	// Tracks whether we are using an OpenGL-backed renderer or a Vulkan-backed renderer
+	// Tracks what graphics API is backing our renderer
 	bool usingGL = false;
 	bool usingVk = false;
 	bool usingMtl = false;

include/panda_qt/screen.hpp

@@ -9,14 +9,14 @@
 
 // OpenGL widget for drawing the 3DS screen
 class ScreenWidget : public QWidget {
-	enum class API { OpenGL, Metal, Vulkan };
-
 	Q_OBJECT
 
   public:
 	using ResizeCallback = std::function<void(u32, u32)>;
 
-	ScreenWidget(ResizeCallback resizeCallback, QWidget* parent = nullptr);
+	enum class API { OpenGL, Metal, Vulkan };
+
+	ScreenWidget(API api, ResizeCallback resizeCallback, QWidget* parent = nullptr);
 	void resizeEvent(QResizeEvent* event) override;
 	// Called by the emulator thread for resizing the actual GL surface, since the emulator thread owns the GL context
 	void resizeSurface(u32 width, u32 height);

include/renderer.hpp

@@ -101,11 +101,6 @@ class Renderer {
 	// Returns whether this draw is eligible for using hardware-accelerated shaders or if shaders should run on the CPU
 	virtual bool prepareForDraw(ShaderUnit& shaderUnit, PICA::DrawAcceleration* accel) { return false; }
 
-	// Functions for initializing the graphics context for the Qt frontend, where we don't have the convenience of SDL_Window
-#ifdef PANDA3DS_FRONTEND_QT
-	virtual void initGraphicsContext(GL::Context* context) { Helpers::panic("Tried to initialize incompatible renderer with GL context"); }
-#endif
-
 	void setFBSize(u32 width, u32 height) {
 		fbSize[0] = width;
 		fbSize[1] = height;

include/renderer_gl/renderer_gl.hpp

@@ -211,10 +211,6 @@ class RendererGL final : public Renderer {
 	void resetStateManager() { gl.reset(); }
 	void initUbershader(OpenGL::Program& program);
 
-#ifdef PANDA3DS_FRONTEND_QT
-	virtual void initGraphicsContext([[maybe_unused]] GL::Context* context) override { initGraphicsContextInternal(); }
-#endif
-
 	// Take a screenshot of the screen and store it in a file
 	void screenshot(const std::string& name) override;
 };

include/renderer_mtl/renderer_mtl.hpp

@@ -37,10 +37,6 @@ class RendererMTL final : public Renderer {
 	void screenshot(const std::string& name) override;
 	void deinitGraphicsContext() override;
 
-#ifdef PANDA3DS_FRONTEND_QT
-	virtual void initGraphicsContext([[maybe_unused]] GL::Context* context) override {}
-#endif
-
 	virtual void setMTKLayer(void* layer) override;
 
   private:

include/renderer_null/renderer_null.hpp

@@ -20,8 +20,4 @@ class RendererNull final : public Renderer {
 	// Tell the GPU core that we'll handle vertex fetch & shader execution in the renderer in order to speed up execution.
 	// Of course, we don't do this and geometry is never actually processed, since this is the null renderer.
 	virtual bool prepareForDraw(ShaderUnit& shaderUnit, PICA::DrawAcceleration* accel) override { return true; };
-
-#ifdef PANDA3DS_FRONTEND_QT
-	virtual void initGraphicsContext([[maybe_unused]] GL::Context* context) override {}
-#endif
 };

include/renderer_sw/renderer_sw.hpp

@@ -16,8 +16,4 @@ class RendererSw final : public Renderer {
 	void drawVertices(PICA::PrimType primType, std::span<const PICA::Vertex> vertices) override;
 	void screenshot(const std::string& name) override;
 	void deinitGraphicsContext() override;
-
-#ifdef PANDA3DS_FRONTEND_QT
-	virtual void initGraphicsContext([[maybe_unused]] GL::Context* context) override {}
-#endif
 };

src/core/renderer_mtl/renderer_mtl.cpp

@@ -57,8 +57,6 @@ void RendererMTL::reset() {
 	colorRenderTargetCache.reset();
 }
 
-void RendererMTL::setMTKLayer(void* layer) {
-	metalLayer = (CA::MetalLayer*)layer;
 void RendererMTL::setMTKLayer(void* layer) { metalLayer = (CA::MetalLayer*)layer; }
 
 void RendererMTL::display() {

src/panda_qt/main_window.cpp

@@ -25,8 +25,19 @@ MainWindow::MainWindow(QApplication* app, QWidget* parent) : QMainWindow(parent)
 	resize(800, 240 * 4);
 	show();
 
+	const RendererType rendererType = emu->getConfig().rendererType;
+	usingGL = (rendererType == RendererType::OpenGL || rendererType == RendererType::Software || rendererType == RendererType::Null);
+	usingVk = (rendererType == RendererType::Vulkan);
+	usingMtl = (rendererType == RendererType::Metal);
+
+	ScreenWidget::API api = ScreenWidget::API::OpenGL;
+	if (usingVk)
+		api = ScreenWidget::API::Vulkan;
+	else if (usingMtl)
+		api = ScreenWidget::API::Metal;
+
 	// We pass a callback to the screen widget that will be triggered every time we resize the screen
-	screen = new ScreenWidget([this](u32 width, u32 height) { handleScreenResize(width, height); }, this);
+	screen = new ScreenWidget(api, [this](u32 width, u32 height) { handleScreenResize(width, height); }, this);
 	setCentralWidget(screen);
 
 	appRunning = true;
@@ -149,29 +160,29 @@ MainWindow::MainWindow(QApplication* app, QWidget* parent) : QMainWindow(parent)
 
 	// The emulator graphics context for the thread should be initialized in the emulator thread due to how GL contexts work
 	emuThread = std::thread([this]() {
-		const RendererType rendererType = emu->getConfig().rendererType;
-		usingGL = (rendererType == RendererType::OpenGL || rendererType == RendererType::Software || rendererType == RendererType::Null);
-		usingVk = (rendererType == RendererType::Vulkan);
-		usingMtl = (rendererType == RendererType::Metal);
+		switch (screen->api) {
+			case ScreenWidget::API::OpenGL: {
+				// Make GL context current for this thread, enable VSync
+				GL::Context* glContext = screen->getGLContext();
+				glContext->MakeCurrent();
+				glContext->SetSwapInterval(emu->getConfig().vsyncEnabled ? 1 : 0);
 
-		if (usingGL) {
-			// Make GL context current for this thread, enable VSync
-			GL::Context* glContext = screen->getGLContext();
-			glContext->MakeCurrent();
-			glContext->SetSwapInterval(emu->getConfig().vsyncEnabled ? 1 : 0);
+				if (glContext->IsGLES()) {
+					emu->getRenderer()->setupGLES();
+				}
 
-			if (glContext->IsGLES()) {
-				emu->getRenderer()->setupGLES();
+				emu->initGraphicsContext(glContext);
+				break;
 			}
 
-			emu->initGraphicsContext(glContext);
-		} else if (usingVk) {
-			Helpers::panic("Vulkan on Qt is currently WIP, try the SDL frontend instead!");
-		} else if (usingMtl) {
-			emu->initGraphicsContext((void*)nullptr);
-			emu->getRenderer()->setMTKLayer(screen->getMTKLayer());
-		} else {
-			Helpers::panic("Unsupported graphics backend for Qt frontend!");
+			case ScreenWidget::API::Metal: {
+				emu->initGraphicsContext(nullptr);
+				emu->getRenderer()->setMTKLayer(screen->getMTKLayer());
+				break;
+			}
+
+			case ScreenWidget::API::Vulkan: Helpers::panic("Vulkan on Qt is currently WIP, try the SDL frontend instead!"); break;
+			default: Helpers::panic("Unsupported graphics backend for Qt frontend!"); break;
 		}
 
 		// We have to initialize controllers on the same thread they'll be polled in

src/panda_qt/screen.cpp

@@ -18,10 +18,8 @@
 // and https://github.com/melonDS-emu/melonDS/blob/master/src/frontend/qt_sdl/main.cpp
 
 #ifdef PANDA3DS_ENABLE_OPENGL
-ScreenWidget::ScreenWidget(ResizeCallback resizeCallback, QWidget* parent) : QWidget(parent), resizeCallback(resizeCallback) {
+ScreenWidget::ScreenWidget(API api, ResizeCallback resizeCallback, QWidget* parent) : api(api), QWidget(parent), resizeCallback(resizeCallback) {
 	// Create a native window for use with our graphics API of choice
-	resize(800, 240 * 4);
-
 	setAutoFillBackground(false);
 	setAttribute(Qt::WA_NativeWindow, true);
 	setAttribute(Qt::WA_NoSystemBackground, true);
@@ -29,7 +27,6 @@ ScreenWidget::ScreenWidget(ResizeCallback resizeCallback, QWidget* parent) : QWi
 	setAttribute(Qt::WA_KeyCompression, false);
 	setFocusPolicy(Qt::StrongFocus);
 	setMouseTracking(true);
-	show();
 
 	if (api == API::OpenGL) {
 		if (!createGLContext()) {
@@ -42,6 +39,9 @@ ScreenWidget::ScreenWidget(ResizeCallback resizeCallback, QWidget* parent) : QWi
 	} else {
 		Helpers::panic("Unspported api for Qt screen widget");
 	}
+
+	resize(800, 240 * 4);
+	show();
 }
 
 void ScreenWidget::resizeEvent(QResizeEvent* event) {