src/third_party/skia/src/core/SkPictureReplacementPlayback.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 SkPictureReplacementPlayback_DEFINED
   9 #define SkPictureReplacementPlayback_DEFINED
  10
  11 #include "SkPicturePlayback.h"
  12
  13 // This playback class replaces complete "saveLayer ... restore" runs with a
  14 // single drawBitmap call.
  15 class SkPictureReplacementPlayback : public SkPicturePlayback {
  16 public:
  17     // PlaybackReplacements collects op ranges that can be replaced with
  18     // a single drawBitmap call (using a precomputed bitmap).
  19     class PlaybackReplacements {
  20     public:
  21         // All the operations between fStart and fStop (inclusive) will be replaced with
  22         // a single drawBitmap call using fPos, fBM and fPaint.
  23         // fPaint will be NULL if the picture's paint wasn't copyable
  24         struct ReplacementInfo {
  25             size_t          fStart;
  26             size_t          fStop;
  27             SkIPoint        fPos;
  28             SkBitmap*       fBM;     // fBM is allocated so ReplacementInfo can remain POD
  29             const SkPaint*  fPaint;  // Note: this object doesn't own the paint
  30
  31             SkIRect         fSrcRect;
  32         };
  33
  34         ~PlaybackReplacements() { this->freeAll(); }
  35
  36         // Add a new replacement range. The replacement ranges should be
  37         // sorted in increasing order and non-overlapping (esp. no nested
  38         // saveLayers).
  39         ReplacementInfo* push();
  40
  41         // look up a replacement range by its start offset
  42         ReplacementInfo* lookupByStart(size_t start);
  43
  44     private:
  45         SkTDArray<ReplacementInfo> fReplacements;
  46
  47         void freeAll();
  48
  49 #ifdef SK_DEBUG
  50         void validate() const;
  51 #endif
  52     };
  53
  54     // This class doesn't take ownership of either 'replacements' or 'activeOpsList'
  55     // The caller must guarantee they exist across any calls to 'draw'.
  56     // 'activeOpsList' can be NULL but in that case BBH acceleration will not
  57     // be used ('replacements' can be NULL too but that defeats the purpose
  58     // of using this class).
  59     SkPictureReplacementPlayback(const SkPicture* picture,
  60                                  PlaybackReplacements* replacements,
  61                                  const SkPicture::OperationList* activeOpsList)
  62         : INHERITED(picture)
  63         , fReplacements(replacements)
  64         , fActiveOpsList(activeOpsList) {
  65     }
  66
  67     virtual void draw(SkCanvas* canvas, SkDrawPictureCallback*) SK_OVERRIDE;
  68
  69 private:
  70     PlaybackReplacements*           fReplacements;
  71     const SkPicture::OperationList* fActiveOpsList;
  72
  73     // This method checks if the current op pointed at by 'iter' and 'reader'
  74     // is within a replacement range. If so, it issues the drawBitmap call,
  75     // updates 'iter' and 'reader' to be after the restore operation, and
  76     // returns true. If the operation is not in a replacement range (and thus
  77     // needs to be drawn normally) false is returned.
  78     bool replaceOps(SkPictureStateTree::Iterator* iter,
  79                     SkReader32* reader,
  80                     SkCanvas* canvas,
  81                     const SkMatrix& initialMatrix);
  82
  83     typedef SkPicturePlayback INHERITED;
  84 };
  85
  86 #endif