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 #include "Test.h"
9 
10 #include "../include/core/SkCanvas.h"
11 #include "../include/core/SkPicture.h"
12 #include "../include/core/SkStream.h"
13 #include "../include/core/SkString.h"
14 #include "../include/core/SkPictureRecorder.h"
15 #include <cstring>
16 
17 // Verify that replay of a recording into a clipped canvas
18 // produces the correct bitmap.
19 // This arose from http://crbug.com/401593 which has
20 // https://code.google.com/p/skia/issues/detail?id=1291 as its root cause.
21 
22 namespace {
23 
24 class Drawer {
25  public:
Drawer()26     explicit Drawer() : fImageInfo(SkImageInfo::MakeN32Premul(200, 100)) {
27         fCircleBM.allocPixels(SkImageInfo::MakeN32Premul(100, 100));
28         SkCanvas canvas(fCircleBM);
29         canvas.clear(0xffffffff);
30         SkPaint circlePaint;
31         circlePaint.setColor(0xff000000);
32         canvas.drawCircle(50, 50, 50, circlePaint);
33     }
34 
imageInfo() const35     const SkImageInfo& imageInfo() const { return fImageInfo; }
36 
draw(SkCanvas * canvas,const SkRect & clipRect,SkXfermode::Mode mode) const37     void draw(SkCanvas* canvas, const SkRect& clipRect, SkXfermode::Mode mode) const {
38         SkPaint greenPaint;
39         greenPaint.setColor(0xff008000);
40         SkPaint blackPaint;
41         blackPaint.setColor(0xff000000);
42         SkPaint whitePaint;
43         whitePaint.setColor(0xffffffff);
44         SkPaint layerPaint;
45         layerPaint.setColor(0xff000000);
46         layerPaint.setXfermodeMode(mode);
47         SkRect canvasRect(SkRect::MakeWH(SkIntToScalar(fImageInfo.width()),
48                                          SkIntToScalar(fImageInfo.height())));
49 
50         canvas->clipRect(clipRect);
51         canvas->clear(0xff000000);
52 
53         canvas->saveLayer(nullptr, &blackPaint);
54             canvas->drawRect(canvasRect, greenPaint);
55             canvas->saveLayer(nullptr, &layerPaint);
56                 canvas->drawBitmapRect(fCircleBM, SkRect::MakeXYWH(20,20,60,60), &blackPaint);
57             canvas->restore();
58         canvas->restore();
59     }
60 
61  private:
62     const SkImageInfo fImageInfo;
63     SkBitmap fCircleBM;
64 };
65 
66 class RecordingStrategy {
67  public:
~RecordingStrategy()68     virtual ~RecordingStrategy() {}
69     virtual const SkBitmap& recordAndReplay(const Drawer& drawer,
70                                             const SkRect& intoClip,
71                                             SkXfermode::Mode) = 0;
72 };
73 
74 class BitmapBackedCanvasStrategy : public RecordingStrategy {
75     // This version just draws into a bitmap-backed canvas.
76  public:
BitmapBackedCanvasStrategy(const SkImageInfo & imageInfo)77     BitmapBackedCanvasStrategy(const SkImageInfo& imageInfo) {
78         fBitmap.allocPixels(imageInfo);
79     }
80 
recordAndReplay(const Drawer & drawer,const SkRect & intoClip,SkXfermode::Mode mode)81     virtual const SkBitmap& recordAndReplay(const Drawer& drawer,
82                                             const SkRect& intoClip,
83                                             SkXfermode::Mode mode) {
84         SkCanvas canvas(fBitmap);
85         canvas.clear(0xffffffff);
86         // Note that the scene is drawn just into the clipped region!
87         canvas.clipRect(intoClip);
88         drawer.draw(&canvas, intoClip, mode); // Shouild be canvas-wide...
89         return fBitmap;
90     }
91 
92  private:
93     SkBitmap fBitmap;
94 };
95 
96 class PictureStrategy : public RecordingStrategy {
97     // This version draws the entire scene into an SkPictureRecorder.
98     // Then it then replays the scene through a clip rectangle.
99     // This backend proved to be buggy.
100  public:
PictureStrategy(const SkImageInfo & imageInfo)101     PictureStrategy(const SkImageInfo& imageInfo) {
102         fBitmap.allocPixels(imageInfo);
103         fWidth  = imageInfo.width();
104         fHeight = imageInfo.height();
105     }
106 
recordAndReplay(const Drawer & drawer,const SkRect & intoClip,SkXfermode::Mode mode)107     virtual const SkBitmap& recordAndReplay(const Drawer& drawer,
108                                             const SkRect& intoClip,
109                                             SkXfermode::Mode mode) {
110         SkRTreeFactory factory;
111         SkPictureRecorder recorder;
112         SkRect canvasRect(SkRect::MakeWH(SkIntToScalar(fWidth),SkIntToScalar(fHeight)));
113         SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(fWidth),
114                                                    SkIntToScalar(fHeight),
115                                                    &factory);
116         drawer.draw(canvas, canvasRect, mode);
117         SkAutoTUnref<SkPicture> picture(recorder.endRecording());
118 
119         SkCanvas replayCanvas(fBitmap);
120         replayCanvas.clear(0xffffffff);
121         replayCanvas.clipRect(intoClip);
122         picture->playback(&replayCanvas);
123         return fBitmap;
124     }
125 
126  private:
127     SkBitmap fBitmap;
128     int fWidth;
129     int fHeight;
130 };
131 
132 } // namespace
133 
134 
DEF_TEST(SkRecordingAccuracyXfermode,reporter)135 DEF_TEST(SkRecordingAccuracyXfermode, reporter) {
136 #define FINEGRAIN 0
137     const Drawer drawer;
138 
139     BitmapBackedCanvasStrategy golden(drawer.imageInfo());
140     PictureStrategy picture(drawer.imageInfo());
141 
142 #if !FINEGRAIN
143     unsigned numErrors = 0;
144     SkString errors;
145 #endif
146 
147     for (int iMode = 0; iMode < int(SkXfermode::kLastMode); iMode++) {
148         const SkRect& clip = SkRect::MakeXYWH(100, 0, 100, 100);
149         SkXfermode::Mode mode = SkXfermode::Mode(iMode);
150 
151         const SkBitmap& goldenBM = golden.recordAndReplay(drawer, clip, mode);
152         const SkBitmap& pictureBM = picture.recordAndReplay(drawer, clip, mode);
153 
154         size_t pixelsSize = goldenBM.getSize();
155         REPORTER_ASSERT(reporter, pixelsSize == pictureBM.getSize());
156 
157         // The pixel arrays should match.
158 #if FINEGRAIN
159         REPORTER_ASSERT(reporter,
160                         0 == memcmp(goldenBM.getPixels(), pictureBM.getPixels(), pixelsSize));
161 #else
162         if (memcmp(goldenBM.getPixels(), pictureBM.getPixels(), pixelsSize)) {
163             numErrors++;
164             errors.appendf("For SkXfermode %d %s:    SkPictureRecorder bitmap is wrong\n",
165                            iMode, SkXfermode::ModeName(mode));
166         }
167 #endif
168     }
169 
170 #if !FINEGRAIN
171     REPORTER_ASSERT_MESSAGE(reporter, 0 == numErrors, errors.c_str());
172 #endif
173 }
174