src/third_party/skia/include/core/SkMultiPictureDraw.h

   1 /*
   2  * Copyright 2014 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #ifndef SkMultiPictureDraw_DEFINED
   9 #define SkMultiPictureDraw_DEFINED
  10
  11 #include "SkMatrix.h"
  12 #include "SkTDArray.h"
  13
  14 class SkCanvas;
  15 class SkPaint;
  16 class SkPicture;
  17
  18 /** \class SkMultiPictureDraw
  19
  20     The MultiPictureDraw object accepts several picture/canvas pairs and
  21     then attempts to optimally draw the pictures into the canvases, sharing
  22     as many resources as possible.
  23 */
  24 class SK_API SkMultiPictureDraw {
  25 public:
  26     /**
  27      *  Create an object to optimize the drawing of multiple pictures.
  28      *  @param reserve Hint for the number of add calls expected to be issued
  29      */
  30     SkMultiPictureDraw(int reserve = 0);
  31     ~SkMultiPictureDraw() { this->reset(); }
  32
  33     /**
  34      *  Add a canvas/picture pair for later rendering.
  35      *  @param canvas   the canvas in which to draw picture
  36      *  @param picture  the picture to draw into canvas
  37      *  @param matrix   if non-NULL, applied to the CTM when drawing
  38      *  @param paint    if non-NULL, draw picture to a temporary buffer
  39      *                  and then apply the paint when the result is drawn
  40      */
  41     void add(SkCanvas* canvas,
  42              const SkPicture* picture,
  43              const SkMatrix* matrix = NULL,
  44              const SkPaint* paint = NULL);
  45
  46     /**
  47      *  Perform all the previously added draws. This will reset the state
  48      *  of this object.
  49      */
  50     void draw();
  51
  52     /**
  53      *  Abandon all buffered draws and reset to the initial state.
  54      */
  55     void reset();
  56
  57 private:
  58     struct DrawData {
  59         SkCanvas*        fCanvas;  // reffed
  60         const SkPicture* fPicture; // reffed
  61         SkMatrix         fMatrix;
  62         SkPaint*         fPaint;   // owned
  63
  64         void init(SkCanvas*, const SkPicture*, const SkMatrix*, const SkPaint*);
  65         void draw();
  66
  67         static void Reset(SkTDArray<DrawData>&);
  68
  69         static void Draw(DrawData* d) { d->draw(); }
  70     };
  71
  72     SkTDArray<DrawData> fThreadSafeDrawData;
  73     SkTDArray<DrawData> fGPUDrawData;
  74 };
  75
  76 #endif