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 // 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_