1 /*
2  * Copyright 2016 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 SkOverdrawCanvas_DEFINED
9 #define SkOverdrawCanvas_DEFINED
10 
11 #include "SkCanvasVirtualEnforcer.h"
12 #include "SkNWayCanvas.h"
13 
14 /**
15  *  Captures all drawing commands.  Rather than draw the actual content, this device
16  *  increments the alpha channel of each pixel every time it would have been touched
17  *  by a draw call.  This is useful for detecting overdraw.
18  */
19 class SK_API SkOverdrawCanvas : public SkCanvasVirtualEnforcer<SkNWayCanvas> {
20 public:
21     /* Does not take ownership of canvas */
22     SkOverdrawCanvas(SkCanvas*);
23 
24     void onDrawTextBlob(const SkTextBlob*, SkScalar, SkScalar, const SkPaint&) override;
25     void onDrawPatch(const SkPoint[12], const SkColor[4], const SkPoint[4], SkBlendMode,
26                      const SkPaint&) override;
27     void onDrawPaint(const SkPaint&) override;
28     void onDrawRect(const SkRect&, const SkPaint&) override;
29     void onDrawEdgeAARect(const SkRect&, SkCanvas::QuadAAFlags, SkColor, SkBlendMode) override;
30     void onDrawRegion(const SkRegion&, const SkPaint&) override;
31     void onDrawOval(const SkRect&, const SkPaint&) override;
32     void onDrawArc(const SkRect&, SkScalar, SkScalar, bool, const SkPaint&) override;
33     void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) override;
34     void onDrawRRect(const SkRRect&, const SkPaint&) override;
35     void onDrawPoints(PointMode, size_t, const SkPoint[], const SkPaint&) override;
36     void onDrawVerticesObject(const SkVertices*, const SkVertices::Bone bones[], int boneCount,
37                               SkBlendMode, const SkPaint&) override;
38     void onDrawAtlas(const SkImage*, const SkRSXform[], const SkRect[], const SkColor[],
39                      int, SkBlendMode, const SkRect*, const SkPaint*) override;
40     void onDrawPath(const SkPath&, const SkPaint&) override;
41     void onDrawImage(const SkImage*, SkScalar, SkScalar, const SkPaint*) override;
42     void onDrawImageRect(const SkImage*, const SkRect*, const SkRect&, const SkPaint*,
43                          SrcRectConstraint) override;
44     void onDrawImageNine(const SkImage*, const SkIRect&, const SkRect&, const SkPaint*) override;
45     void onDrawImageLattice(const SkImage*, const Lattice&, const SkRect&, const SkPaint*) override;
46     void onDrawImageSet(const ImageSetEntry[], int count, SkFilterQuality, SkBlendMode) override;
47     void onDrawBitmap(const SkBitmap&, SkScalar, SkScalar, const SkPaint*) override;
48     void onDrawBitmapRect(const SkBitmap&, const SkRect*, const SkRect&, const SkPaint*,
49                           SrcRectConstraint) override;
50     void onDrawBitmapNine(const SkBitmap&, const SkIRect&, const SkRect&, const SkPaint*) override;
51     void onDrawBitmapLattice(const SkBitmap&, const Lattice&, const SkRect&,
52                              const SkPaint*) override;
53     void onDrawDrawable(SkDrawable*, const SkMatrix*) override;
54     void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) override;
55 
56     void onDrawAnnotation(const SkRect&, const char key[], SkData* value) override;
57     void onDrawShadowRec(const SkPath&, const SkDrawShadowRec&) override;
58 
59 private:
60     void drawPosTextCommon(const SkGlyphID[], int, const SkScalar[], int, const SkPoint&,
61                            const SkFont&, const SkPaint&);
62 
63     inline SkPaint overdrawPaint(const SkPaint& paint);
64 
65     SkPaint   fPaint;
66 
67     typedef SkCanvasVirtualEnforcer<SkNWayCanvas> INHERITED;
68 };
69 
70 #endif
71