From fd30fe77df10d33ef86a56a54cc1516b192af9af Mon Sep 17 00:00:00 2001
From: offtkp <parisoplop@gmail.com>
Date: Wed, 31 Jul 2024 18:40:41 +0300
Subject: [PATCH] Context shenanigans

---
 src/core/renderer_gl/async_compiler.cpp | 14 ++++++-----
 src/jni_driver.cpp                      | 33 +++++++++++++++++++++++++
 src/panda_sdl/frontend_sdl.cpp          | 17 +++----------
 3 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/src/core/renderer_gl/async_compiler.cpp b/src/core/renderer_gl/async_compiler.cpp
index 800aec49..a6de1136 100644
--- a/src/core/renderer_gl/async_compiler.cpp
+++ b/src/core/renderer_gl/async_compiler.cpp
@@ -4,9 +4,8 @@
 #include "glad/gl.h"
 #include "opengl.hpp"
 
-namespace Frontend::AsyncCompiler {
+namespace AsyncCompiler {
     void* createContext(void* userdata);
-    void makeCurrent(void* userdata, void* context);
     void destroyContext(void* userdata, void* context);
 }
 
@@ -40,9 +39,12 @@ bool AsyncCompilerState::PopCompiledProgram(CompiledProgram*& program)
 }
 
 void AsyncCompilerState::Start() {
-    void* context = Frontend::AsyncCompiler::createContext(contextCreationUserdata);
-    shaderCompilationThread = std::thread([this, context]() {
-        Frontend::AsyncCompiler::makeCurrent(contextCreationUserdata, context);
+    shaderCompilationThread = std::thread([this]() {
+        void* context = AsyncCompiler::createContext(contextCreationUserdata);
+        if (!context) {
+            Helpers::panic("Failed to create async compiler context");
+        }
+
         printf("Async compiler started, version: %s\n", glGetString(GL_VERSION));
         std::string defaultShadergenVSSource = fragShaderGen.getDefaultVertexShader();
 	    defaultShadergenVs.create({defaultShadergenVSSource.c_str(), defaultShadergenVSSource.size()}, OpenGL::Vertex);
@@ -85,7 +87,7 @@ void AsyncCompilerState::Start() {
             std::this_thread::yield();
         }
 
-        Frontend::AsyncCompiler::destroyContext(contextCreationUserdata, context);
+        AsyncCompiler::destroyContext(contextCreationUserdata, context);
     });
 }
 
diff --git a/src/jni_driver.cpp b/src/jni_driver.cpp
index e4ce2b39..355856a1 100644
--- a/src/jni_driver.cpp
+++ b/src/jni_driver.cpp
@@ -18,6 +18,10 @@ JavaVM* jvm = nullptr;
 jclass alberClass;
 jmethodID alberClassOpenDocument;
 
+EGLSurface eglSurface = EGL_NO_SURFACE;
+EGLDisplay eglDisplay = EGL_NO_DISPLAY;
+int eglVersion = 0;
+
 #define AlberFunction(type, name) JNIEXPORT type JNICALL Java_com_panda3ds_pandroid_AlberDriver_##name
 
 void throwException(JNIEnv* env, const char* message) {
@@ -70,6 +74,10 @@ AlberFunction(void, Initialize)(JNIEnv* env, jobject obj) {
 		return throwException(env, "Failed to load OpenGL ES 2.0");
 	}
 
+	eglDisplay = eglGetCurrentDisplay();
+	eglSurface = eglGetCurrentSurface(EGL_DRAW);
+	eglQueryContext(eglDisplay, eglGetCurrentContext(), EGL_CONTEXT_CLIENT_VERSION, &eglVersion);
+
 	__android_log_print(ANDROID_LOG_INFO, "AlberDriver", "OpenGL ES %d.%d", GLVersion.major, GLVersion.minor);
 	emulator->initGraphicsContext(nullptr);
 }
@@ -139,4 +147,29 @@ int AndroidUtils::openDocument(const char* path, const char* perms) {
     env->DeleteLocalRef(jmode);
 
     return (int)result;
+}
+
+namespace AsyncCompiler {
+	void createContext(void* userdata) {
+		EGLint attribList[] = {
+			EGL_CONTEXT_CLIENT_VERSION, eglVersion,
+			EGL_NONE
+		};
+
+		EGLContext threadContext = eglCreateContext(eglDisplay, eglSurface, EGL_NO_CONTEXT, attribList);
+		if (threadContext == EGL_NO_CONTEXT) {
+			throwException(jniEnv(), "Failed to create EGL context");
+		}
+
+		if (!eglMakeCurrent(eglDisplay, eglSurface, eglSurface, threadContext)) {
+			throwException(jniEnv(), "Failed to make EGL context current");
+		}
+
+		__android_log_print(ANDROID_LOG_INFO, "AlberDriver", "Async compiler started, version: %s", glGetString(GL_VERSION));
+	}
+
+	void destroyContext(void* userdata, void* context) {
+		eglMakeCurrent(eglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+		eglDestroyContext(eglDisplay, (EGLContext)context);
+	}
 }
\ No newline at end of file
diff --git a/src/panda_sdl/frontend_sdl.cpp b/src/panda_sdl/frontend_sdl.cpp
index 4c1df3d8..68e32d94 100644
--- a/src/panda_sdl/frontend_sdl.cpp
+++ b/src/panda_sdl/frontend_sdl.cpp
@@ -344,12 +344,12 @@ void FrontendSDL::run() {
 	}
 }
 
-namespace Frontend::AsyncCompiler {
+namespace AsyncCompiler {
 	void* createContext(void* userdata) {
 		SDL_Window* window = static_cast<SDL_Window*>(userdata);
-		SDL_GLContext previousContext = SDL_GL_GetCurrentContext();
-		SDL_GLContext context = SDL_GL_CreateContext(window); // this sets it as current :(
-		SDL_GL_MakeCurrent(window, previousContext);
+
+		// SDL_GL_CreateContext also makes it the current context
+		SDL_GLContext context = SDL_GL_CreateContext(window);
 
 		if (context == nullptr) {
 			Helpers::panic("OpenGL context creation failed: %s", SDL_GetError());
@@ -358,15 +358,6 @@ namespace Frontend::AsyncCompiler {
 		return context;
 	}
 
-	void makeCurrent(void* userdata, void* context) {
-		SDL_Window* window = static_cast<SDL_Window*>(userdata);
-		int result = SDL_GL_MakeCurrent(window, context);
-
-		if (result < 0) {
-			Helpers::panic("OpenGL context make current failed: %s", SDL_GetError());
-		}
-	}
-
 	void destroyContext(void* userdata, void* context) {
 		SDL_GL_DeleteContext(static_cast<SDL_GLContext>(context));
 	}