Unobfuscate RWHVMac accelerated compositing code path by separating it from plugin code

content/browser/renderer_host/compositing_iosurface_mac.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_ACCELERATED_COMPOSITING_VIEW_MAC_H
+#define CONTENT_BROWSER_RENDERER_HOST_ACCELERATED_COMPOSITING_VIEW_MAC_H
+
+#import <Cocoa/Cocoa.h>
+#include <QuartzCore/QuartzCore.h>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "base/memory/scoped_nsobject.h"
+#include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/size.h"
+
+class IOSurfaceSupport;
+
+// This class manages an OpenGL context and IOSurface for the accelerated
+// compositing code path. The GL context is attached to
+// RenderWidgetHostViewCocoa for blitting the IOSurface.
+class CompositingIOSurfaceMac {
+ public:
+  // Returns NULL if IOSurface support is missing or GL APIs fail.
+  static CompositingIOSurfaceMac* Create();
+  ~CompositingIOSurfaceMac();
+
+  // Set IOSurface that will be drawn on the next NSView drawRect.
+  void SetIOSurface(uint64 io_surface_handle);
+
+  // Blit the IOSurface at the upper-left corner of the |view|. If |view| window
+  // size is larger than the IOSurface, the remaining left and bottom edges will
+  // be white.
+  void DrawIOSurface(NSView* view);
+
+  // Unref the IOSurface and delete the associated GL texture. If the GPU
+  // process is no longer referencing it, this will delete the IOSurface.
+  void UnrefIOSurface();
+
+  // Call when globalFrameDidChange is received on the NSView.
+  void GlobalFrameDidChange();
+
+  // Disassociate the GL context with the NSView and unref the IOSurface. Do
+  // this to switch to software drawing mode.
+  void ClearDrawable();
+
+  bool HasIOSurface() { return !!io_surface_.get(); }
+
+  const gfx::Size& io_surface_size() const { return io_surface_size_; }
+
+ private:
+  // Vertex structure for use in glDraw calls.
+  struct SurfaceVertex {
+    SurfaceVertex() : x_(0.0f), y_(0.0f), tx_(0.0f), ty_(0.0f) { }
+    // Currently the texture coords are always the same as vertex coords.
+    void set(float x, float y, float tx, float ty) {
+      x_ = x;
+      y_ = y;
+      tx_ = tx;
+      ty_ = ty;
+    }
+    float x_;
+    float y_;
+    float tx_;
+    float ty_;
+  };
+
+  // Counter-clockwise verts starting from upper-left corner (0, 0).
+  struct SurfaceQuad {
+    void set_size(gfx::Size size) {
+      // Texture coordinates are flipped vertically so they can be drawn on
+      // a projection with a flipped y-axis (origin is top left).
+      float w = static_cast<float>(size.width());
+      float h = static_cast<float>(size.height());
+      verts_[0].set(0.0f, 0.0f, 0.0f, h);
+      verts_[1].set(0.0f, h, 0.0f, 0.0f);
+      verts_[2].set(w, h, w, 0.0f);
+      verts_[3].set(w, 0.0f, w, h);
+    }
+    SurfaceVertex verts_[4];
+  };
+
+  CompositingIOSurfaceMac(IOSurfaceSupport* io_surface_support,
+                          NSOpenGLContext* glContext,
+                          CGLContextObj cglContext);
+
+  // Returns true if IOSurface is ready to render. False otherwise.
+  bool MapIOSurfaceToTexture(uint64 io_surface_handle);
+
+  void UnrefIOSurfaceWithContextCurrent();
+
+  // Cached pointer to IOSurfaceSupport Singleton.
+  IOSurfaceSupport* io_surface_support_;
+
+  // GL context
+  scoped_nsobject<NSOpenGLContext> glContext_;
+  CGLContextObj cglContext_;  // weak, backed by |glContext_|.
+
+  // IOSurface data.
+  uint64 io_surface_handle_;
+  base::mac::ScopedCFTypeRef<CFTypeRef> io_surface_;
+
+  // The width and height of the io surface.
+  gfx::Size io_surface_size_;
+
+  // The "live" OpenGL texture referring to this IOSurfaceRef. Note
+  // that per the CGLTexImageIOSurface2D API we do not need to
+  // explicitly update this texture's contents once created. All we
+  // need to do is ensure it is re-bound before attempting to draw
+  // with it.
+  GLuint texture_;
+
+  SurfaceQuad quad_;
+};
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_ACCELERATED_COMPOSITING_VIEW_MAC_H