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