GBM Ozone implementation

ui/ozone/platform/dri/gbm_surface.h

+// Copyright 2014 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 UI_OZONE_PLATFORM_DRI_GBM_SURFACE_H_
+#define UI_OZONE_PLATFORM_DRI_GBM_SURFACE_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/ozone/platform/dri/scanout_surface.h"
+
+struct gbm_bo;
+struct gbm_device;
+struct gbm_surface;
+
+namespace ui {
+
+class DriBuffer;
+class DriWrapper;
+
+// Implement the ScanoutSurface interface on top of GBM (Generic Buffer
+// Manager). GBM provides generic access to hardware accelerated surfaces which
+// can be used in association with EGL to provide accelerated drawing.
+class GbmSurface : public ScanoutSurface {
+ public:
+  GbmSurface(gbm_device* device, DriWrapper* dri, const gfx::Size& size);
+  virtual ~GbmSurface();
+
+  // ScanoutSurface:
+  virtual bool Initialize() OVERRIDE;
+  virtual uint32_t GetFramebufferId() const OVERRIDE;
+  virtual uint32_t GetHandle() const OVERRIDE;
+  virtual gfx::Size Size() const OVERRIDE;
+  virtual void SwapBuffers() OVERRIDE;
+
+  // Before scheduling the backbuffer to be scanned out we need to "lock" it.
+  // When we lock it, GBM will give a pointer to a buffer representing the
+  // backbuffer. It will also update its information on which buffers can not be
+  // used for drawing. The buffer will be released when the page flip event
+  // occurs (see SwapBuffers). This is called from GbmSurfaceFactory before
+  // scheduling a page flip.
+  void LockCurrentDrawable();
+
+  gbm_surface* native_surface() { return native_surface_; };
+
+ private:
+  gbm_device* gbm_device_;
+
+  DriWrapper* dri_;
+
+  gfx::Size size_;
+
+  // The native GBM surface. In EGL this represents the EGLNativeWindowType.
+  gbm_surface* native_surface_;
+
+  // Backing GBM buffers. One is the current front buffer. The other is the
+  // current backbuffer that is pending scan out.
+  gbm_bo* buffers_[2];
+
+  // Index to the front buffer.
+  int front_buffer_;
+
+  // We can't lock (and get) an accelerated buffer from the GBM surface until
+  // after something draws into it. But modesetting needs to happen earlier,
+  // before an actual window is created and draws. So, we create a dumb buffer
+  // for this purpose.
+  scoped_ptr<DriBuffer> dumb_buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(GbmSurface);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_DRI_GBM_SURFACE_H_