1 /*
2  * Copyright 2013 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 "gm/gm.h"
9 #include "include/core/SkBitmap.h"
10 #include "include/core/SkBlendMode.h"
11 #include "include/core/SkCanvas.h"
12 #include "include/core/SkColor.h"
13 #include "include/core/SkImage.h"
14 #include "include/core/SkImageFilter.h"
15 #include "include/core/SkPaint.h"
16 #include "include/core/SkRect.h"
17 #include "include/core/SkRefCnt.h"
18 #include "include/core/SkScalar.h"
19 #include "include/core/SkSize.h"
20 #include "include/core/SkString.h"
21 #include "include/core/SkTypes.h"
22 #include "include/effects/SkImageFilters.h"
23 #include "tools/ToolUtils.h"
24 
25 #include <utility>
26 
27 #define WIDTH 600
28 #define HEIGHT 700
29 #define MARGIN 12
30 
31 namespace skiagm {
32 
33 class XfermodeImageFilterGM : public GM {
34 public:
XfermodeImageFilterGM()35     XfermodeImageFilterGM(){
36         this->setBGColor(0xFF000000);
37     }
38 
39 protected:
onShortName()40     SkString onShortName() override {
41         return SkString("xfermodeimagefilter");
42     }
43 
onISize()44     SkISize onISize() override {
45         return SkISize::Make(WIDTH, HEIGHT);
46     }
47 
onOnceBeforeDraw()48     void onOnceBeforeDraw() override {
49         fBitmap = ToolUtils::create_string_bitmap(80, 80, 0xD000D000, 15, 65, 96, "e");
50 
51         fCheckerboard = SkImage::MakeFromBitmap(
52                 ToolUtils::create_checkerboard_bitmap(80, 80, 0xFFA0A0A0, 0xFF404040, 8));
53     }
54 
onDraw(SkCanvas * canvas)55     void onDraw(SkCanvas* canvas) override {
56         canvas->clear(SK_ColorBLACK);
57         SkPaint paint;
58 
59         const SkBlendMode gModes[] = {
60             SkBlendMode::kClear,
61             SkBlendMode::kSrc,
62             SkBlendMode::kDst,
63             SkBlendMode::kSrcOver,
64             SkBlendMode::kDstOver,
65             SkBlendMode::kSrcIn,
66             SkBlendMode::kDstIn,
67             SkBlendMode::kSrcOut,
68             SkBlendMode::kDstOut,
69             SkBlendMode::kSrcATop,
70             SkBlendMode::kDstATop,
71             SkBlendMode::kXor,
72 
73             SkBlendMode::kPlus,
74             SkBlendMode::kModulate,
75             SkBlendMode::kScreen,
76             SkBlendMode::kOverlay,
77             SkBlendMode::kDarken,
78             SkBlendMode::kLighten,
79             SkBlendMode::kColorDodge,
80             SkBlendMode::kColorBurn,
81             SkBlendMode::kHardLight,
82             SkBlendMode::kSoftLight,
83             SkBlendMode::kDifference,
84             SkBlendMode::kExclusion,
85             SkBlendMode::kMultiply,
86             SkBlendMode::kHue,
87             SkBlendMode::kSaturation,
88             SkBlendMode::kColor,
89             SkBlendMode::kLuminosity,
90         };
91 
92         int x = 0, y = 0;
93         sk_sp<SkImageFilter> background(SkImageFilters::Image(fCheckerboard));
94         for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); i++) {
95             paint.setImageFilter(SkImageFilters::Xfermode(gModes[i], background));
96             DrawClippedBitmap(canvas, fBitmap, paint, x, y);
97             x += fBitmap.width() + MARGIN;
98             if (x + fBitmap.width() > WIDTH) {
99                 x = 0;
100                 y += fBitmap.height() + MARGIN;
101             }
102         }
103         // Test arithmetic mode as image filter
104         paint.setImageFilter(SkImageFilters::Arithmetic(0, 1, 1, 0, true, background, nullptr));
105         DrawClippedBitmap(canvas, fBitmap, paint, x, y);
106         x += fBitmap.width() + MARGIN;
107         if (x + fBitmap.width() > WIDTH) {
108             x = 0;
109             y += fBitmap.height() + MARGIN;
110         }
111         // Test nullptr mode
112         paint.setImageFilter(SkImageFilters::Xfermode(SkBlendMode::kSrcOver, background));
113         DrawClippedBitmap(canvas, fBitmap, paint, x, y);
114         x += fBitmap.width() + MARGIN;
115         if (x + fBitmap.width() > WIDTH) {
116             x = 0;
117             y += fBitmap.height() + MARGIN;
118         }
119         SkRect clipRect = SkRect::MakeWH(SkIntToScalar(fBitmap.width() + 4),
120                                          SkIntToScalar(fBitmap.height() + 4));
121         // Test offsets on SrcMode (uses fixed-function blend)
122         sk_sp<SkImage> bitmapImage(SkImage::MakeFromBitmap(fBitmap));
123         sk_sp<SkImageFilter> foreground(SkImageFilters::Image(std::move(bitmapImage)));
124         sk_sp<SkImageFilter> offsetForeground(SkImageFilters::Offset(4, -4, foreground));
125         sk_sp<SkImageFilter> offsetBackground(SkImageFilters::Offset(4, 4, background));
126         paint.setImageFilter(SkImageFilters::Xfermode(
127                 SkBlendMode::kSrcOver, offsetBackground, offsetForeground));
128         DrawClippedPaint(canvas, clipRect, paint, x, y);
129         x += fBitmap.width() + MARGIN;
130         if (x + fBitmap.width() > WIDTH) {
131             x = 0;
132             y += fBitmap.height() + MARGIN;
133         }
134         // Test offsets on Darken (uses shader blend)
135         paint.setImageFilter(SkImageFilters::Xfermode(
136                 SkBlendMode::kDarken, offsetBackground, offsetForeground));
137         DrawClippedPaint(canvas, clipRect, paint, x, y);
138         x += fBitmap.width() + MARGIN;
139         if (x + fBitmap.width() > WIDTH) {
140             x = 0;
141             y += fBitmap.height() + MARGIN;
142         }
143         // Test cropping
144         constexpr size_t nbSamples = 3;
145         const SkBlendMode sampledModes[nbSamples] = {
146             SkBlendMode::kOverlay, SkBlendMode::kSrcOver, SkBlendMode::kPlus
147         };
148         int offsets[nbSamples][4] = {{ 10,  10, -16, -16},
149                                      { 10,  10,  10,  10},
150                                      {-10, -10,  -6,  -6}};
151         for (size_t i = 0; i < nbSamples; ++i) {
152             SkIRect cropRect = SkIRect::MakeXYWH(offsets[i][0],
153                                                  offsets[i][1],
154                                                  fBitmap.width()  + offsets[i][2],
155                                                  fBitmap.height() + offsets[i][3]);
156             paint.setImageFilter(SkImageFilters::Xfermode(sampledModes[i], offsetBackground,
157                                                           offsetForeground, &cropRect));
158             DrawClippedPaint(canvas, clipRect, paint, x, y);
159             x += fBitmap.width() + MARGIN;
160             if (x + fBitmap.width() > WIDTH) {
161                 x = 0;
162                 y += fBitmap.height() + MARGIN;
163             }
164         }
165         // Test small bg, large fg with Screen (uses shader blend)
166         SkIRect cropRect = SkIRect::MakeXYWH(10, 10, 60, 60);
167         sk_sp<SkImageFilter> cropped(SkImageFilters::Offset(0, 0, foreground, &cropRect));
168         paint.setImageFilter(SkImageFilters::Xfermode(SkBlendMode::kScreen, cropped, background,
169                                                       nullptr));
170         DrawClippedPaint(canvas, clipRect, paint, x, y);
171         x += fBitmap.width() + MARGIN;
172         if (x + fBitmap.width() > WIDTH) {
173             x = 0;
174             y += fBitmap.height() + MARGIN;
175         }
176         // Test small fg, large bg with Screen (uses shader blend)
177         paint.setImageFilter(SkImageFilters::Xfermode(SkBlendMode::kScreen, background, cropped,
178                                                       nullptr));
179         DrawClippedPaint(canvas, clipRect, paint, x, y);
180         x += fBitmap.width() + MARGIN;
181         if (x + fBitmap.width() > WIDTH) {
182             x = 0;
183             y += fBitmap.height() + MARGIN;
184         }
185         // Test small fg, large bg with SrcIn with a crop that forces it to full size.
186         // This tests that SkXfermodeImageFilter correctly applies the compositing mode to
187         // the region outside the foreground.
188         SkIRect cropRectFull = SkIRect::MakeXYWH(0, 0, 80, 80);
189         paint.setImageFilter(SkImageFilters::Xfermode(SkBlendMode::kSrcIn, background, cropped,
190                                                       &cropRectFull));
191         DrawClippedPaint(canvas, clipRect, paint, x, y);
192         x += fBitmap.width() + MARGIN;
193         if (x + fBitmap.width() > WIDTH) {
194             x = 0;
195             y += fBitmap.height() + MARGIN;
196         }
197     }
198 
199 private:
DrawClippedBitmap(SkCanvas * canvas,const SkBitmap & bitmap,const SkPaint & paint,int x,int y)200     static void DrawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
201                                   int x, int y) {
202         canvas->save();
203         canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
204         canvas->clipRect(SkRect::MakeIWH(bitmap.width(), bitmap.height()));
205         canvas->drawBitmap(bitmap, 0, 0, &paint);
206         canvas->restore();
207     }
208 
DrawClippedPaint(SkCanvas * canvas,const SkRect & rect,const SkPaint & paint,int x,int y)209     static void DrawClippedPaint(SkCanvas* canvas, const SkRect& rect, const SkPaint& paint,
210                                  int x, int y) {
211         canvas->save();
212         canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
213         canvas->clipRect(rect);
214         canvas->drawPaint(paint);
215         canvas->restore();
216     }
217 
218     SkBitmap        fBitmap;
219     sk_sp<SkImage>  fCheckerboard;
220 
221     typedef GM INHERITED;
222 };
223 
224 //////////////////////////////////////////////////////////////////////////////
225 
226 DEF_GM( return new XfermodeImageFilterGM; );
227 
228 }
229