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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 drawPath(const SkPath&, const SkPaint&);
     24     bool drawRect(const SkRect&, const SkPaint&);
     25     bool drawTextBlob(const SkTextBlob*, SkScalar x, SkScalar y, const SkPaint&);
     26 
     27     // Detach anything we've recorded as a picture, resetting this SkMiniRecorder.
     28     // If cull is nullptr we'll calculate it.
     29     sk_sp<SkPicture> detachAsPicture(const SkRect* cull);
     30 
     31     // Flush anything we've recorded to the canvas, resetting this SkMiniRecorder.
     32     // This is logically the same as but rather more efficient than:
     33     //    sk_sp<SkPicture> pic(this->detachAsPicture(nullptr));
     34     //    pic->playback(canvas);
     35     void flushAndReset(SkCanvas*);
     36 
     37 private:
     38     enum class State {
     39         kEmpty,
     40         kDrawPath,
     41         kDrawRect,
     42         kDrawTextBlob,
     43     };
     44 
     45     State fState;
     46 
     47     template <size_t A, size_t B>
     48     struct Max { static const size_t val = A > B ? A : B; };
     49 
     50     static const size_t kInlineStorage =
     51         Max<sizeof(SkRecords::DrawPath),
     52         Max<sizeof(SkRecords::DrawRect),
     53             sizeof(SkRecords::DrawTextBlob)>::val>::val;
     54     SkAlignedSStorage<kInlineStorage> fBuffer;
     55 };
     56 
     57 #endif//SkMiniRecorder_DEFINED
     58