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 "cc/base/cc_export.h"
  10 #include "skia/ext/refptr.h"
  11 // TODO(robertphillips): change this to "class SkBaseDevice;"
  12 #include "third_party/skia/include/core/SkDevice.h"
  13 #include "ui/gfx/rect.h"
  14 #include "ui/gfx/size.h"
  15 #include "ui/gfx/vector2d.h"
  16
  17 class SkBitmap;
  18 class SkCanvas;
  19
  20 namespace cc {
  21
  22 class SoftwareFrameData;
  23
  24 // This is a "tear-off" class providing software drawing support to
  25 // OutputSurface, such as to a platform-provided window framebuffer.
  26 class CC_EXPORT SoftwareOutputDevice {
  27  public:
  28   SoftwareOutputDevice();
  29   virtual ~SoftwareOutputDevice();
  30
  31   // Discards any pre-existing backing buffers and allocates memory for a
  32   // software device of |size|. This must be called before the
  33   // |SoftwareOutputDevice| can be used in other ways.
  34   virtual void Resize(gfx::Size size);
  35
  36   // Called on BeginDrawingFrame. The compositor will draw into the returned
  37   // SkCanvas. The |SoftwareOutputDevice| implementation needs to provide a
  38   // valid SkCanvas of at least size |damage_rect|. This class retains ownership
  39   // of the SkCanvas.
  40   virtual SkCanvas* BeginPaint(gfx::Rect damage_rect);
  41
  42   // Called on FinishDrawingFrame. The compositor will no longer mutate the the
  43   // SkCanvas instance returned by |BeginPaint| and should discard any reference
  44   // that it holds to it.
  45   virtual void EndPaint(SoftwareFrameData* frame_data);
  46
  47   // Copies pixels inside |rect| from the current software framebuffer to
  48   // |output|. Fails if there is no current softwareframebuffer.
  49   virtual void CopyToBitmap(gfx::Rect rect, SkBitmap* output);
  50
  51   // Blit the pixel content of the SoftwareOutputDevice by |delta| with the
  52   // write clipped to |clip_rect|.
  53   virtual void Scroll(gfx::Vector2d delta,
  54                       gfx::Rect clip_rect);
  55
  56   // Discard the backing buffer in the surface provided by this instance.
  57   virtual void DiscardBackbuffer() {}
  58
  59   // Ensures that there is a backing buffer available on this instance.
  60   virtual void EnsureBackbuffer() {}
  61
  62   // TODO(skaslev) Remove this after UberCompositor lands.
  63   // Called in response to receiving a SwapBuffersAck. At this point, software
  64   // frame identified by id can be reused or discarded as it is no longer being
  65   // displayed.
  66   virtual void ReclaimSoftwareFrame(unsigned id);
  67
  68  protected:
  69   gfx::Size viewport_size_;
  70   gfx::Rect damage_rect_;
  71   skia::RefPtr<SkBaseDevice> device_;
  72   skia::RefPtr<SkCanvas> canvas_;
  73
  74  private:
  75   DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDevice);
  76 };
  77
  78 }  // namespace cc
  79
  80 #endif  // CC_OUTPUT_SOFTWARE_OUTPUT_DEVICE_H_