Massive cleanup of initialisation/destruction of OpenGL resources

Includes cleanup of the LibRetro EmuWindow implementation

Fixes #40

src/citra_libretro/citra_libretro.cpp

@@ -118,12 +118,7 @@ uintptr_t LibRetro::GetFramebuffer() {
 /**
  * Updates Citra's settings with Libretro's.
  */
-void UpdateSettings(bool init) {
-    // Check to see if we actually have any config updates to process.
-    if (!init && !LibRetro::HasUpdatedConfig()) {
-        return;
-    }
-
+void UpdateSettings() {
     struct retro_input_descriptor desc[] = {
         {0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT, "Left"},
         {0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP, "Up"},
@@ -308,8 +303,8 @@ void UpdateSettings(bool init) {
         }
     }
 
-    // Update the framebuffer sizing, but only if there is a oGL context.
-    emu_instance->emu_window->Prepare(!init);
+    // Update the framebuffer sizing.
+    emu_instance->emu_window->UpdateLayout();
 
     Settings::Apply();
 }
@@ -318,7 +313,10 @@ void UpdateSettings(bool init) {
  * libretro callback; Called every game tick.
  */
 void retro_run() {
-    UpdateSettings(false);
+    // Check to see if we actually have any config updates to process.
+    if (LibRetro::HasUpdatedConfig()) {
+        UpdateSettings();
+    }
 
     // We can't assume that the frontend has been nice and preserved all OpenGL settings. Reset.
     auto last_state = OpenGLState::GetCurState();
@@ -387,14 +385,17 @@ void context_reset() {
         LOG_ERROR(Render, "initialization failed!");
     }
 
-    emu_instance->emu_window->Prepare(true);
+    emu_instance->emu_window->UpdateLayout();
+    emu_instance->emu_window->CreateContext();
 }
 
 void context_destroy() {
     if (VideoCore::g_renderer != nullptr) {
         VideoCore::g_renderer->ShutDown();
-        VideoCore::g_renderer = nullptr;
     }
+
+    emu_instance->emu_window->DestroyContext();
+    VideoCore::g_renderer = nullptr;
 }
 
 void retro_reset() {
@@ -433,8 +434,7 @@ bool retro_load_game(const struct retro_game_info* info) {
     }
 
     emu_instance->emu_window = std::make_unique<EmuWindow_LibRetro>();
-
-    UpdateSettings(true);
+    UpdateSettings();
 
     const Core::System::ResultStatus load_result{Core::System::GetInstance().Load(
         emu_instance->emu_window.get(), LibRetro::settings.file_path)};

src/citra_libretro/emu_window/libretro_window.cpp

@@ -58,9 +58,8 @@ void EmuWindow_LibRetro::SwapBuffers() {
 
     ResetGLState();
 
-    if (enableEmulatedPointer) {
-        // TODO: Port tracker to OpenGLState
-        tracker.Render(width, height);
+    if (tracker != nullptr) {
+        tracker->Render(width, height);
     }
 
     LibRetro::UploadVideoFrame(RETRO_HW_FRAME_BUFFER_VALID, static_cast<unsigned>(width),
@@ -88,11 +87,11 @@ void EmuWindow_LibRetro::PollEvents() {
 
     // TODO: Poll for right click for motion emu
 
-    if (enableEmulatedPointer) {
-        tracker.Update(width, height, GetFramebufferLayout().bottom_screen);
+    if (tracker != nullptr) {
+        tracker->Update(width, height, GetFramebufferLayout().bottom_screen);
 
-        if (tracker.IsPressed()) {
-            auto mousePos = tracker.GetPressedPosition();
+        if (tracker->IsPressed()) {
+            auto mousePos = tracker->GetPressedPosition();
 
             if (hasTouched) {
                 TouchMoved(mousePos.first, mousePos.second);
@@ -121,7 +120,7 @@ void EmuWindow_LibRetro::OnMinimalClientAreaChangeRequest(
     height = minimal_size.second;
 }
 
-void EmuWindow_LibRetro::Prepare(bool hasOGL) {
+void EmuWindow_LibRetro::UpdateLayout() {
     // TODO: Handle custom layouts
     // TODO: Extract this ugly thing somewhere else
     unsigned baseX;
@@ -200,17 +199,6 @@ void EmuWindow_LibRetro::Prepare(bool hasOGL) {
     NotifyClientAreaSizeChanged(std::pair<unsigned, unsigned>(baseX, baseY));
     OnMinimalClientAreaChangeRequest(std::pair<unsigned, unsigned>(baseX, baseY));
     UpdateCurrentFramebufferLayout(baseX, baseY);
-
-    if (hasOGL) {
-        framebuffer = static_cast<GLuint>(LibRetro::GetFramebuffer());
-
-        if (enableEmulatedPointer) {
-            // TODO: This is potentially leaking OpenGL resources!
-            tracker.InitOpenGL();
-        }
-
-        doCleanFrame = true;
-    }
 }
 
 bool EmuWindow_LibRetro::ShouldDeferRendererInit() const {
@@ -228,3 +216,17 @@ bool EmuWindow_LibRetro::HasSubmittedFrame() {
     submittedFrame = false;
     return state;
 }
+
+void EmuWindow_LibRetro::CreateContext() {
+    framebuffer = static_cast<GLuint>(LibRetro::GetFramebuffer());
+
+    if (enableEmulatedPointer) {
+        tracker = std::make_unique<LibRetro::Input::MouseTracker>();
+    }
+
+    doCleanFrame = true;
+}
+
+void EmuWindow_LibRetro::DestroyContext() {
+    tracker = nullptr;
+}

src/citra_libretro/emu_window/libretro_window.h

@@ -34,7 +34,7 @@ public:
     void SetupFramebuffer() override;
 
     /// Prepares the window for rendering
-    void Prepare(bool hasOGL);
+    void UpdateLayout();
 
     /// Enables for deferring a renderer's initalisation.
     bool ShouldDeferRendererInit() const override;
@@ -45,6 +45,12 @@ public:
     /// Flags that the framebuffer should be cleared.
     bool NeedsClearing() const override;
 
+    /// Creates state for a currently running OpenGL context.
+    void CreateContext();
+
+    /// Destroys a currently running OpenGL context.
+    void DestroyContext();
+
 private:
     /// Called when a configuration change affects the minimal size of the window
     void OnMinimalClientAreaChangeRequest(
@@ -65,7 +71,7 @@ private:
     GLuint framebuffer;
 
     // For tracking mouse cursor
-    LibRetro::Input::MouseTracker tracker;
+    std::unique_ptr<LibRetro::Input::MouseTracker> tracker = nullptr;
 
     bool enableEmulatedPointer = true;
 };

src/citra_libretro/input/mouse_tracker.cpp

@@ -16,7 +16,7 @@ namespace LibRetro {
 
 namespace Input {
 
-void MouseTracker::InitOpenGL() {
+MouseTracker::MouseTracker() {
     // Could potentially also use Citra's built-in shaders, if they can be
     //  wrangled to cooperate.
     const GLchar* vertex = R"(
@@ -41,11 +41,11 @@ void MouseTracker::InitOpenGL() {
         }
     )";
 
-    glGenVertexArrays(1, &vao);
-    glBindVertexArray(vao);
+    vao.Create();
+    vbo.Create();
 
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBindVertexArray(vao.handle);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo.handle);
 
     shader.Create(vertex, fragment);
 
@@ -55,6 +55,12 @@ void MouseTracker::InitOpenGL() {
     glVertexAttribPointer(positionVariable, 2, GL_FLOAT, GL_FALSE, 0, 0);
 }
 
+MouseTracker::~MouseTracker() {
+    shader.Release();
+    vao.Release();
+    vbo.Release();
+}
+
 void MouseTracker::OnMouseMove(int deltaX, int deltaY) {
     x += deltaX;
     y += deltaY;
@@ -165,7 +171,7 @@ void MouseTracker::Render(int bufferWidth, int bufferHeight) {
 
     glUseProgram(shader.handle);
 
-    glBindVertexArray(vao);
+    glBindVertexArray(vao.handle);
 
     // clang-format off
     GLfloat cursor[] = {
@@ -192,7 +198,7 @@ void MouseTracker::Render(int bufferWidth, int bufferHeight) {
     glEnable(GL_BLEND);
     glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ONE_MINUS_SRC_COLOR);
 
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo.handle);
     glBufferData(GL_ARRAY_BUFFER, sizeof(cursor), cursor, GL_STATIC_DRAW);
 
     glDrawArrays(GL_TRIANGLES, 0, 12);

src/citra_libretro/input/mouse_tracker.h

@@ -16,8 +16,8 @@ namespace Input {
 ///  for a touch-screen device.
 class MouseTracker {
 public:
-    /// Initalises OpenGL.
-    void InitOpenGL();
+    MouseTracker();
+    ~MouseTracker();
 
     /// Called whenever a mouse moves.
     void OnMouseMove(int xDelta, int yDelta);
@@ -56,8 +56,8 @@ private:
     bool isPressed;
 
     OGLProgram shader;
-    GLuint vbo;
-    GLuint vao;
+    OGLVertexArray vao;
+    OGLBuffer vbo;
 
     MathUtil::Rectangle<unsigned> bottomScreen;
 };