1 /*
2  * Copyright 2018 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.h"
9 #include "sk_tool_utils.h"
10 #include "SkBitmap.h"
11 #include "SkTextUtils.h"
12 
13 namespace skiagm {
14 
15 // This GM recreates the blend mode images from the Android documentation
16 class AndroidBlendModesGM : public GM {
17 public:
AndroidBlendModesGM()18     AndroidBlendModesGM() {
19         this->setBGColor(SK_ColorBLACK);
20     }
21 
22 protected:
onShortName()23     SkString onShortName() override {
24         return SkString("androidblendmodes");
25     }
26 
onISize()27     SkISize onISize() override {
28         return SkISize::Make(kNumCols * kBitmapSize, kNumRows * kBitmapSize);
29     }
30 
onOnceBeforeDraw()31     void onOnceBeforeDraw() override {
32         SkImageInfo ii = SkImageInfo::MakeN32Premul(kBitmapSize, kBitmapSize);
33         {
34             fCompositeSrc.allocPixels(ii);
35             SkCanvas tmp(fCompositeSrc);
36             tmp.clear(SK_ColorTRANSPARENT);
37             SkPaint p;
38             p.setAntiAlias(true);
39             p.setColor(sk_tool_utils::color_to_565(kBlue));
40             tmp.drawRect(SkRect::MakeLTRB(16, 96, 160, 240), p);
41         }
42 
43         {
44             fCompositeDst.allocPixels(ii);
45             SkCanvas tmp(fCompositeDst);
46             tmp.clear(SK_ColorTRANSPARENT);
47             SkPaint p;
48             p.setAntiAlias(true);
49             p.setColor(sk_tool_utils::color_to_565(kRed));
50             tmp.drawCircle(160, 95, 80, p);
51         }
52     }
53 
drawTile(SkCanvas * canvas,int xOffset,int yOffset,SkBlendMode mode)54     void drawTile(SkCanvas* canvas, int xOffset, int yOffset, SkBlendMode mode) {
55         canvas->translate(xOffset, yOffset);
56 
57         canvas->clipRect(SkRect::MakeXYWH(0, 0, 256, 256));
58 
59         canvas->saveLayer(nullptr, nullptr);
60 
61         SkPaint p;
62         canvas->drawBitmap(fCompositeDst, 0, 0, &p);
63         p.setBlendMode(mode);
64         canvas->drawBitmap(fCompositeSrc, 0, 0, &p);
65     }
66 
onDraw(SkCanvas * canvas)67     void onDraw(SkCanvas* canvas) override {
68         SkFont font(sk_tool_utils::create_portable_typeface());
69 
70         sk_tool_utils::draw_checkerboard(canvas,
71                                          kWhite,
72                                          kGrey,
73                                          32);
74 
75         int xOffset = 0, yOffset = 0;
76 
77         // Android doesn't expose all the blend modes
78         // Note that the Android documentation calls:
79         //    Skia's kPlus,     add
80         //    Skia's kModulate, multiply
81         for (SkBlendMode mode : { SkBlendMode::kPlus /* add */, SkBlendMode::kClear,
82                                   SkBlendMode::kDarken, SkBlendMode::kDst,
83                                   SkBlendMode::kDstATop, SkBlendMode::kDstIn,
84                                   SkBlendMode::kDstOut, SkBlendMode::kDstOver,
85                                   SkBlendMode::kLighten, SkBlendMode::kModulate /* multiply */,
86                                   SkBlendMode::kOverlay, SkBlendMode::kScreen,
87                                   SkBlendMode::kSrc, SkBlendMode::kSrcATop,
88                                   SkBlendMode::kSrcIn, SkBlendMode::kSrcOut,
89                                   SkBlendMode::kSrcOver, SkBlendMode::kXor } ) {
90 
91             int saveCount = canvas->save();
92             this->drawTile(canvas, xOffset, yOffset, mode);
93             canvas->restoreToCount(saveCount);
94 
95             SkTextUtils::DrawString(canvas, SkBlendMode_Name(mode),
96                                xOffset + kBitmapSize/2.0f,
97                                yOffset + kBitmapSize,
98                                font, SkPaint(), SkTextUtils::kCenter_Align);
99 
100             xOffset += 256;
101             if (xOffset >= 1024) {
102                 xOffset = 0;
103                 yOffset += 256;
104             }
105         }
106     }
107 
108 private:
109     static const int kBitmapSize = 256;
110     static const int kNumRows = 5;
111     static const int kNumCols = 4;
112 
113     static const SkColor  kBlue  = SkColorSetARGB(255, 22, 150, 243);
114     static const SkColor  kRed   = SkColorSetARGB(255, 233, 30, 99);
115     static const SkColor  kWhite = SkColorSetARGB(255, 243, 243, 243);
116     static const SkColor  kGrey  = SkColorSetARGB(255, 222, 222, 222);
117 
118     SkBitmap fCompositeSrc;
119     SkBitmap fCompositeDst;
120 
121     typedef GM INHERITED;
122 };
123 
124 //////////////////////////////////////////////////////////////////////////////
125 
126 DEF_GM(return new AndroidBlendModesGM;)
127 }
128