Merge pull request #2017 from jroweboy/glwidget

Frontend: Migrate to QOpenGLWindow and support shared contexts

1 files changed, 30 insertions, 9 deletions

diff --git a/src/core/frontend/emu_window.h b/src/core/frontend/emu_window.h
index d0bcb4660..70a522556 100644
--- a/src/core/frontend/emu_window.h
+++ b/src/core/frontend/emu_window.h
@@ -13,6 +13,23 @@
 namespace Core::Frontend {
 
 /**
+ * Represents a graphics context that can be used for background computation or drawing. If the
+ * graphics backend doesn't require the context, then the implementation of these methods can be
+ * stubs
+ */
+class GraphicsContext {
+public:
+    /// Makes the graphics context current for the caller thread
+    virtual void MakeCurrent() = 0;
+
+    /// Releases (dunno if this is the "right" word) the context from the caller thread
+    virtual void DoneCurrent() = 0;
+
+    /// Swap buffers to display the next frame
+    virtual void SwapBuffers() = 0;
+};
+
+/**
  * Abstraction class used to provide an interface between emulation code and the frontend
  * (e.g. SDL, QGLWidget, GLFW, etc...).
  *
@@ -30,7 +47,7 @@ namespace Core::Frontend {
  * - DO NOT TREAT THIS CLASS AS A GUI TOOLKIT ABSTRACTION LAYER. That's not what it is. Please
  *   re-read the upper points again and think about it if you don't see this.
  */
-class EmuWindow {
+class EmuWindow : public GraphicsContext {
 public:
     /// Data structure to store emuwindow configuration
     struct WindowConfig {
@@ -40,17 +57,21 @@ public:
         std::pair<unsigned, unsigned> min_client_area_size;
     };
 
-    /// Swap buffers to display the next frame
-    virtual void SwapBuffers() = 0;
-
     /// Polls window events
     virtual void PollEvents() = 0;
 
-    /// Makes the graphics context current for the caller thread
-    virtual void MakeCurrent() = 0;
-
-    /// Releases (dunno if this is the "right" word) the GLFW context from the caller thread
-    virtual void DoneCurrent() = 0;
+    /**
+     * Returns a GraphicsContext that the frontend provides that is shared with the emu window. This
+     * context can be used from other threads for background graphics computation. If the frontend
+     * is using a graphics backend that doesn't need anything specific to run on a different thread,
+     * then it can use a stubbed implemenation for GraphicsContext.
+     *
+     * If the return value is null, then the core should assume that the frontend cannot provide a
+     * Shared Context
+     */
+    virtual std::unique_ptr<GraphicsContext> CreateSharedContext() const {
+        return nullptr;
+    }
 
     /**
      * Signal that a touch pressed event has occurred (e.g. mouse click pressed)