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      1 /*
      2  * Copyright 2015 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 SkMiniRecorder_DEFINED
      9 #define SkMiniRecorder_DEFINED
     10 
     11 #include "SkRecords.h"
     12 #include "SkScalar.h"
     13 #include "SkTypes.h"
     14 class SkCanvas;
     15 
     16 // Records small pictures, but only a limited subset of the canvas API, and may fail.
     17 class SkMiniRecorder : SkNoncopyable {
     18 public:
     19     SkMiniRecorder();
     20     ~SkMiniRecorder();
     21 
     22     // Try to record an op.  Returns false on failure.
     23     bool drawBitmapRect(const SkBitmap&, const SkRect* src, const SkRect& dst,
     24                         const SkPaint*, SkCanvas::SrcRectConstraint);
     25     bool drawPath(const SkPath&, const SkPaint&);
     26     bool drawRect(const SkRect&, const SkPaint&);
     27     bool drawTextBlob(const SkTextBlob*, SkScalar x, SkScalar y, const SkPaint&);
     28 
     29     // Detach anything we've recorded as a picture, resetting this SkMiniRecorder.
     30     SkPicture* detachAsPicture(const SkRect& cull);
     31 
     32     // Flush anything we've recorded to the canvas, resetting this SkMiniRecorder.
     33     // This is logically the same as but rather more efficient than:
     34     //    SkAutoTUnref<SkPicture> pic(this->detachAsPicture(SkRect::MakeEmpty()));
     35     //    pic->playback(canvas);
     36     void flushAndReset(SkCanvas*);
     37 
     38 private:
     39     enum class State {
     40         kEmpty,
     41         kDrawBitmapRectFixedSize,
     42         kDrawPath,
     43         kDrawRect,
     44         kDrawTextBlob,
     45     };
     46 
     47     State fState;
     48 
     49     template <size_t A, size_t B>
     50     struct Max { static const size_t val = A > B ? A : B; };
     51 
     52     static const size_t kInlineStorage =
     53         Max<sizeof(SkRecords::DrawBitmapRectFixedSize),
     54         Max<sizeof(SkRecords::DrawPath),
     55         Max<sizeof(SkRecords::DrawRect),
     56             sizeof(SkRecords::DrawTextBlob)>::val>::val>::val;
     57     SkAlignedSStorage<kInlineStorage> fBuffer;
     58 };
     59 
     60 #endif//SkMiniRecorder_DEFINED
     61