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      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 // TODO(robertphillips): change this to "class SkBaseDevice;"
     13 #include "third_party/skia/include/core/SkDevice.h"
     14 #include "ui/gfx/rect.h"
     15 #include "ui/gfx/size.h"
     16 #include "ui/gfx/vector2d.h"
     17 
     18 class SkBitmap;
     19 class SkCanvas;
     20 
     21 namespace gfx {
     22 class VSyncProvider;
     23 }
     24 
     25 namespace cc {
     26 
     27 class SoftwareFrameData;
     28 
     29 // This is a "tear-off" class providing software drawing support to
     30 // OutputSurface, such as to a platform-provided window framebuffer.
     31 class CC_EXPORT SoftwareOutputDevice {
     32  public:
     33   SoftwareOutputDevice();
     34   virtual ~SoftwareOutputDevice();
     35 
     36   // Discards any pre-existing backing buffers and allocates memory for a
     37   // software device of |size|. This must be called before the
     38   // |SoftwareOutputDevice| can be used in other ways.
     39   virtual void Resize(const gfx::Size& pixel_size, float scale_factor);
     40 
     41   // Called on BeginDrawingFrame. The compositor will draw into the returned
     42   // SkCanvas. The |SoftwareOutputDevice| implementation needs to provide a
     43   // valid SkCanvas of at least size |damage_rect|. This class retains ownership
     44   // of the SkCanvas.
     45   virtual SkCanvas* BeginPaint(const gfx::Rect& damage_rect);
     46 
     47   // Called on FinishDrawingFrame. The compositor will no longer mutate the the
     48   // SkCanvas instance returned by |BeginPaint| and should discard any reference
     49   // that it holds to it.
     50   virtual void EndPaint(SoftwareFrameData* frame_data);
     51 
     52   // Copies pixels inside |rect| from the current software framebuffer to
     53   // |pixels|. Fails if there is no current softwareframebuffer.
     54   virtual void CopyToPixels(const gfx::Rect& rect, void* pixels);
     55 
     56   // Blit the pixel content of the SoftwareOutputDevice by |delta| with the
     57   // write clipped to |clip_rect|.
     58   virtual void Scroll(const gfx::Vector2d& delta, const gfx::Rect& clip_rect);
     59 
     60   // Discard the backing buffer in the surface provided by this instance.
     61   virtual void DiscardBackbuffer() {}
     62 
     63   // Ensures that there is a backing buffer available on this instance.
     64   virtual void EnsureBackbuffer() {}
     65 
     66   // TODO(skaslev) Remove this after UberCompositor lands.
     67   // Called in response to receiving a SwapBuffersAck. At this point, software
     68   // frame identified by id can be reused or discarded as it is no longer being
     69   // displayed.
     70   virtual void ReclaimSoftwareFrame(unsigned id);
     71 
     72   // VSyncProvider used to update the timer used to schedule draws with the
     73   // hardware vsync. Return NULL if a provider doesn't exist.
     74   virtual gfx::VSyncProvider* GetVSyncProvider();
     75 
     76  protected:
     77   gfx::Size viewport_pixel_size_;
     78   float scale_factor_;
     79   gfx::Rect damage_rect_;
     80   skia::RefPtr<SkCanvas> canvas_;
     81   scoped_ptr<gfx::VSyncProvider> vsync_provider_;
     82 
     83  private:
     84   DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDevice);
     85 };
     86 
     87 }  // namespace cc
     88 
     89 #endif  // CC_OUTPUT_SOFTWARE_OUTPUT_DEVICE_H_
     90