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