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      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 "../private/SkTDArray.h"
     12 #include "SkMatrix.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. If flush is true, all canvases are flushed after
     49      *  draw.
     50      */
     51     void draw(bool flush = false);
     52 
     53     /**
     54      *  Abandon all buffered draws and reset to the initial state.
     55      */
     56     void reset();
     57 
     58 private:
     59     struct DrawData {
     60         SkCanvas*        fCanvas;
     61         const SkPicture* fPicture; // reffed
     62         SkMatrix         fMatrix;
     63         SkPaint*         fPaint;   // owned
     64 
     65         void init(SkCanvas*, const SkPicture*, const SkMatrix*, const SkPaint*);
     66         void draw();
     67 
     68         static void Reset(SkTDArray<DrawData>&);
     69     };
     70 
     71     SkTDArray<DrawData> fThreadSafeDrawData;
     72     SkTDArray<DrawData> fGPUDrawData;
     73 };
     74 
     75 #endif
     76