Frontend/GPU: Refactor context management

Changes the GraphicsContext to be managed by the GPU core. This
eliminates the need for the frontends to fool around with tricky
MakeCurrent/DoneCurrent calls that are dependent on the settings (such
as async gpu option).

This also refactors out the need to use QWidget::fromWindowContainer as
that caused issues with focus and input handling. Now we use a regular
QWidget and just access the native windowHandle() directly.

Another change is removing the debug tool setting in FrameMailbox.
Instead of trying to block the frontend until a new frame is ready, the
core will now take over presentation and draw directly to the window if
the renderer detects that its hooked by NSight or RenderDoc

Lastly, since it was in the way, I removed ScopeAcquireWindowContext and
replaced it with a simple subclass in GraphicsContext that achieves the
same result

3 files changed, 36 insertions, 48 deletions

diff --git a/src/video_core/renderer_opengl/gl_shader_cache.cpp b/src/video_core/renderer_opengl/gl_shader_cache.cpp
index e3d31c3eb..8f59e0442 100644
--- a/src/video_core/renderer_opengl/gl_shader_cache.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_cache.cpp
@@ -305,7 +305,6 @@ void ShaderCacheOpenGL::LoadDiskCache(const std::atomic_bool& stop_loading,
     }
 
     const std::vector gl_cache = disk_cache.LoadPrecompiled();
-    const auto supported_formats = GetSupportedFormats();
 
     // Track if precompiled cache was altered during loading to know if we have to
     // serialize the virtual precompiled cache file back to the hard drive
@@ -327,8 +326,8 @@ void ShaderCacheOpenGL::LoadDiskCache(const std::atomic_bool& stop_loading,
 
     const auto worker = [&](Core::Frontend::GraphicsContext* context, std::size_t begin,
                             std::size_t end) {
-        context->MakeCurrent();
-        SCOPE_EXIT({ return context->DoneCurrent(); });
+        const auto scope = context->Acquire();
+        const auto supported_formats = GetSupportedFormats();
 
         for (std::size_t i = begin; i < end; ++i) {
             if (stop_loading) {
diff --git a/src/video_core/renderer_opengl/renderer_opengl.cpp b/src/video_core/renderer_opengl/renderer_opengl.cpp
index fca5e3ec0..6f08803c1 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.cpp
+++ b/src/video_core/renderer_opengl/renderer_opengl.cpp
@@ -7,9 +7,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <memory>
-
 #include <glad/glad.h>
-
 #include "common/assert.h"
 #include "common/logging/log.h"
 #include "common/microprofile.h"
@@ -30,8 +28,6 @@ namespace OpenGL {
 
 namespace {
 
-// If the size of this is too small, it ends up creating a soft cap on FPS as the renderer will have
-// to wait on available presentation frames.
 constexpr std::size_t SWAP_CHAIN_SIZE = 3;
 
 struct Frame {
@@ -214,7 +210,7 @@ public:
     std::deque<Frame*> present_queue;
     Frame* previous_frame{};
 
-    FrameMailbox() : has_debug_tool{HasDebugTool()} {
+    FrameMailbox() {
         for (auto& frame : swap_chain) {
             free_queue.push(&frame);
         }
@@ -285,13 +281,9 @@ public:
         std::unique_lock lock{swap_chain_lock};
         present_queue.push_front(frame);
         present_cv.notify_one();
-
-        DebugNotifyNextFrame();
     }
 
     Frame* TryGetPresentFrame(int timeout_ms) {
-        DebugWaitForNextFrame();
-
         std::unique_lock lock{swap_chain_lock};
         // wait for new entries in the present_queue
         present_cv.wait_for(lock, std::chrono::milliseconds(timeout_ms),
@@ -317,38 +309,12 @@ public:
         previous_frame = frame;
         return frame;
     }
-
-private:
-    std::mutex debug_synch_mutex;
-    std::condition_variable debug_synch_condition;
-    std::atomic_int frame_for_debug{};
-    const bool has_debug_tool; // When true, using a GPU debugger, so keep frames in lock-step
-
-    /// Signal that a new frame is available (called from GPU thread)
-    void DebugNotifyNextFrame() {
-        if (!has_debug_tool) {
-            return;
-        }
-        frame_for_debug++;
-        std::lock_guard lock{debug_synch_mutex};
-        debug_synch_condition.notify_one();
-    }
-
-    /// Wait for a new frame to be available (called from presentation thread)
-    void DebugWaitForNextFrame() {
-        if (!has_debug_tool) {
-            return;
-        }
-        const int last_frame = frame_for_debug;
-        std::unique_lock lock{debug_synch_mutex};
-        debug_synch_condition.wait(lock,
-                                   [this, last_frame] { return frame_for_debug > last_frame; });
-    }
 };
 
-RendererOpenGL::RendererOpenGL(Core::Frontend::EmuWindow& emu_window, Core::System& system)
-    : VideoCore::RendererBase{emu_window}, emu_window{emu_window}, system{system},
-      frame_mailbox{std::make_unique<FrameMailbox>()} {}
+RendererOpenGL::RendererOpenGL(Core::Frontend::EmuWindow& emu_window, Core::System& system,
+                               Core::Frontend::GraphicsContext& context)
+    : VideoCore::RendererBase{emu_window}, emu_window{emu_window}, system{system}, frame_mailbox{},
+      has_debug_tool{HasDebugTool()}, context{context} {}
 
 RendererOpenGL::~RendererOpenGL() = default;
 
@@ -356,8 +322,6 @@ MICROPROFILE_DEFINE(OpenGL_RenderFrame, "OpenGL", "Render Frame", MP_RGB(128, 12
 MICROPROFILE_DEFINE(OpenGL_WaitPresent, "OpenGL", "Wait For Present", MP_RGB(128, 128, 128));
 
 void RendererOpenGL::SwapBuffers(const Tegra::FramebufferConfig* framebuffer) {
-    render_window.PollEvents();
-
     if (!framebuffer) {
         return;
     }
@@ -413,6 +377,13 @@ void RendererOpenGL::SwapBuffers(const Tegra::FramebufferConfig* framebuffer) {
         m_current_frame++;
         rasterizer->TickFrame();
     }
+
+    render_window.PollEvents();
+    if (has_debug_tool) {
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+        Present(0);
+        context.SwapBuffers();
+    }
 }
 
 void RendererOpenGL::PrepareRendertarget(const Tegra::FramebufferConfig* framebuffer) {
@@ -480,6 +451,8 @@ void RendererOpenGL::LoadColorToActiveGLTexture(u8 color_r, u8 color_g, u8 color
 }
 
 void RendererOpenGL::InitOpenGLObjects() {
+    frame_mailbox = std::make_unique<FrameMailbox>();
+
     glClearColor(Settings::values.bg_red, Settings::values.bg_green, Settings::values.bg_blue,
                  0.0f);
 
@@ -692,12 +665,21 @@ void RendererOpenGL::DrawScreen(const Layout::FramebufferLayout& layout) {
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 }
 
-void RendererOpenGL::TryPresent(int timeout_ms) {
+bool RendererOpenGL::TryPresent(int timeout_ms) {
+    if (has_debug_tool) {
+        LOG_DEBUG(Render_OpenGL,
+                  "Skipping presentation because we are presenting on the main context");
+        return false;
+    }
+    return Present(timeout_ms);
+}
+
+bool RendererOpenGL::Present(int timeout_ms) {
     const auto& layout = render_window.GetFramebufferLayout();
     auto frame = frame_mailbox->TryGetPresentFrame(timeout_ms);
     if (!frame) {
         LOG_DEBUG(Render_OpenGL, "TryGetPresentFrame returned no frame to present");
-        return;
+        return false;
     }
 
     // Clearing before a full overwrite of a fbo can signal to drivers that they can avoid a
@@ -725,6 +707,7 @@ void RendererOpenGL::TryPresent(int timeout_ms) {
     glFlush();
 
     glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+    return true;
 }
 
 void RendererOpenGL::RenderScreenshot() {
diff --git a/src/video_core/renderer_opengl/renderer_opengl.h b/src/video_core/renderer_opengl/renderer_opengl.h
index 33073ce5b..50b647661 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.h
+++ b/src/video_core/renderer_opengl/renderer_opengl.h
@@ -55,13 +55,14 @@ class FrameMailbox;
 
 class RendererOpenGL final : public VideoCore::RendererBase {
 public:
-    explicit RendererOpenGL(Core::Frontend::EmuWindow& emu_window, Core::System& system);
+    explicit RendererOpenGL(Core::Frontend::EmuWindow& emu_window, Core::System& system,
+                            Core::Frontend::GraphicsContext& context);
     ~RendererOpenGL() override;
 
     bool Init() override;
     void ShutDown() override;
     void SwapBuffers(const Tegra::FramebufferConfig* framebuffer) override;
-    void TryPresent(int timeout_ms) override;
+    bool TryPresent(int timeout_ms) override;
 
 private:
     /// Initializes the OpenGL state and creates persistent objects.
@@ -89,8 +90,11 @@ private:
 
     void PrepareRendertarget(const Tegra::FramebufferConfig* framebuffer);
 
+    bool Present(int timeout_ms);
+
     Core::Frontend::EmuWindow& emu_window;
     Core::System& system;
+    Core::Frontend::GraphicsContext& context;
 
     StateTracker state_tracker{system};
 
@@ -115,6 +119,8 @@ private:
 
     /// Frame presentation mailbox
     std::unique_ptr<FrameMailbox> frame_mailbox;
+
+    bool has_debug_tool = false;
 };
 
 } // namespace OpenGL