cc/output/software_output_device.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_OUTPUT_SOFTWARE_OUTPUT_DEVICE_H_
   6 #define CC_OUTPUT_SOFTWARE_OUTPUT_DEVICE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "cc/base/cc_export.h"
  11 #include "skia/ext/refptr.h"
  12 #include "third_party/skia/include/core/SkSurface.h"
  13 #include "ui/gfx/geometry/rect.h"
  14 #include "ui/gfx/geometry/size.h"
  15 #include "ui/gfx/geometry/vector2d.h"
  16
  17 class SkBitmap;
  18 class SkCanvas;
  19
  20 namespace gfx {
  21 class VSyncProvider;
  22 }
  23
  24 namespace cc {
  25
  26 class SoftwareFrameData;
  27
  28 // This is a "tear-off" class providing software drawing support to
  29 // OutputSurface, such as to a platform-provided window framebuffer.
  30 class CC_EXPORT SoftwareOutputDevice {
  31  public:
  32   SoftwareOutputDevice();
  33   virtual ~SoftwareOutputDevice();
  34
  35   // Discards any pre-existing backing buffers and allocates memory for a
  36   // software device of |size|. This must be called before the
  37   // |SoftwareOutputDevice| can be used in other ways.
  38   virtual void Resize(const gfx::Size& pixel_size, float scale_factor);
  39
  40   // Called on BeginDrawingFrame. The compositor will draw into the returned
  41   // SkCanvas. The |SoftwareOutputDevice| implementation needs to provide a
  42   // valid SkCanvas of at least size |damage_rect|. This class retains ownership
  43   // of the SkCanvas.
  44   virtual SkCanvas* BeginPaint(const gfx::Rect& damage_rect);
  45
  46   // Called on FinishDrawingFrame. The compositor will no longer mutate the the
  47   // SkCanvas instance returned by |BeginPaint| and should discard any reference
  48   // that it holds to it.
  49   virtual void EndPaint(SoftwareFrameData* frame_data);
  50
  51   // Discard the backing buffer in the surface provided by this instance.
  52   virtual void DiscardBackbuffer() {}
  53
  54   // Ensures that there is a backing buffer available on this instance.
  55   virtual void EnsureBackbuffer() {}
  56
  57   // TODO(skaslev) Remove this after UberCompositor lands.
  58   // Called in response to receiving a SwapBuffersAck. At this point, software
  59   // frame identified by id can be reused or discarded as it is no longer being
  60   // displayed.
  61   virtual void ReclaimSoftwareFrame(unsigned id);
  62
  63   // VSyncProvider used to update the timer used to schedule draws with the
  64   // hardware vsync. Return NULL if a provider doesn't exist.
  65   virtual gfx::VSyncProvider* GetVSyncProvider();
  66
  67  protected:
  68   gfx::Size viewport_pixel_size_;
  69   float scale_factor_;
  70   gfx::Rect damage_rect_;
  71   skia::RefPtr<SkSurface> surface_;
  72   scoped_ptr<gfx::VSyncProvider> vsync_provider_;
  73
  74  private:
  75   DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDevice);
  76 };
  77
  78 }  // namespace cc
  79
  80 #endif  // CC_OUTPUT_SOFTWARE_OUTPUT_DEVICE_H_