From d167a11b1cddd541bd14c8b0f47e66fa0f19d4fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Thu, 29 Dec 2022 16:14:54 +0100
Subject: [PATCH] SDL: Add a way to reset OpenGL graphics by pressing F7.

---
 Common/GPU/OpenGL/GLFeatures.cpp | 10 +++----
 SDL/SDLGLGraphicsContext.cpp     |  3 +++
 SDL/SDLMain.cpp                  | 45 +++++++++++++++++++++++++++++---
 3 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/Common/GPU/OpenGL/GLFeatures.cpp b/Common/GPU/OpenGL/GLFeatures.cpp
index 9b1e313372..8dee1e98c2 100644
--- a/Common/GPU/OpenGL/GLFeatures.cpp
+++ b/Common/GPU/OpenGL/GLFeatures.cpp
@@ -626,11 +626,11 @@ bool CheckGLExtensions() {
 }
 
 void SetGLCoreContext(bool flag) {
-	_assert_msg_(!extensionsDone, "SetGLCoreContext() after CheckGLExtensions()");
-
-	useCoreContext = flag;
-	// For convenience, it'll get reset later.
-	gl_extensions.IsCoreContext = useCoreContext;
+	if (!extensionsDone) {
+		useCoreContext = flag;
+		// For convenience, it'll get reset later.
+		gl_extensions.IsCoreContext = useCoreContext;
+	}
 }
 
 void ResetGLExtensions() {
diff --git a/SDL/SDLGLGraphicsContext.cpp b/SDL/SDLGLGraphicsContext.cpp
index b3c580d3b4..91b89a4966 100644
--- a/SDL/SDLGLGraphicsContext.cpp
+++ b/SDL/SDLGLGraphicsContext.cpp
@@ -449,9 +449,12 @@ void SDLGLGraphicsContext::Shutdown() {
 void SDLGLGraphicsContext::ShutdownFromRenderThread() {
 	delete draw_;
 	draw_ = nullptr;
+	renderManager_ = nullptr;
 
 #ifdef USING_EGL
 	EGL_Close();
 #endif
 	SDL_GL_DeleteContext(glContext);
+	glContext = nullptr;
+	window_ = nullptr;
 }
diff --git a/SDL/SDLMain.cpp b/SDL/SDLMain.cpp
index c49df319a7..ac47c7b478 100644
--- a/SDL/SDLMain.cpp
+++ b/SDL/SDLMain.cpp
@@ -589,7 +589,7 @@ static void EmuThreadStart(GraphicsContext *context) {
 	emuThread = std::thread(&EmuThreadFunc, context);
 }
 
-static void EmuThreadStop() {
+static void EmuThreadStop(const char *reason) {
 	emuThreadState = (int)EmuThreadState::QUIT_REQUESTED;
 }
 
@@ -931,9 +931,11 @@ int main(int argc, char *argv[]) {
 	
 #if PPSSPP_PLATFORM(MAC)
 	// setup menu items for macOS
-    initializeOSXExtras();
+	initializeOSXExtras();
 #endif
 	
+	bool rebootEmuThread = false;
+
 	while (true) {
 		double startTime = time_now_d();
 
@@ -1046,6 +1048,13 @@ int main(int argc, char *argv[]) {
 					key.keyCode = mapped->second;
 					key.deviceId = DEVICE_ID_KEYBOARD;
 					NativeKey(key);
+
+#ifdef _DEBUG
+					if (k == SDLK_F7 && useEmuThread) {
+						printf("f7 pressed - rebooting emuthread\n");
+						rebootEmuThread = true;
+					}
+#endif
 					break;
 				}
 			case SDL_KEYUP:
@@ -1349,6 +1358,36 @@ int main(int argc, char *argv[]) {
 			}
 		}
 
+		if (rebootEmuThread) {
+			printf("rebooting emu thread");
+			rebootEmuThread = false;
+			EmuThreadStop("shutdown");
+			// Skipping GL calls, the old context is gone.
+			while (graphicsContext->ThreadFrame()) {
+				INFO_LOG(SYSTEM, "graphicsContext->ThreadFrame executed to clear buffers");
+			}
+			EmuThreadJoin();
+			graphicsContext->ThreadEnd();
+			graphicsContext->ShutdownFromRenderThread();
+
+			printf("OK, shutdown complete. starting up graphics again.\n");
+
+			if (g_Config.iGPUBackend == (int)GPUBackend::OPENGL) {
+				SDLGLGraphicsContext *ctx  = (SDLGLGraphicsContext *)graphicsContext;
+				if (!ctx->Init(window, x, y, w, h, mode, &error_message)) {
+					printf("Failed to reinit graphics.\n");
+				}
+			}
+
+			if (!graphicsContext->InitFromRenderThread(&error_message)) {
+				System_Toast("Graphics initialization failed. Quitting.");
+				return 1;
+			}
+
+			EmuThreadStart(graphicsContext);
+			graphicsContext->ThreadStart();
+		}
+
 		// Simple throttling to not burn the GPU in the menu.
 		if (GetUIState() != UISTATE_INGAME || !PSP_IsInited() || renderThreadPaused) {
 			double diffTime = time_now_d() - startTime;
@@ -1361,7 +1400,7 @@ int main(int argc, char *argv[]) {
 	}
 
 	if (useEmuThread) {
-		EmuThreadStop();
+		EmuThreadStop("shutdown");
 		while (graphicsContext->ThreadFrame()) {
 			// Need to keep eating frames to allow the EmuThread to exit correctly.
 			continue;