xref: /aosp_15_r20/external/skia/gm/hairmodes.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2011 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/SkColorPriv.h"
14 #include "include/core/SkMatrix.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/SkShader.h"
20 #include "include/core/SkSize.h"
21 #include "include/core/SkString.h"
22 #include "include/core/SkTileMode.h"
23 #include "include/core/SkTypes.h"
24 
25 constexpr SkBlendMode gModes[] = {
26     SkBlendMode::kClear,
27     SkBlendMode::kSrc,
28     SkBlendMode::kDst,
29     SkBlendMode::kSrcOver,
30     SkBlendMode::kDstOver,
31     SkBlendMode::kSrcIn,
32     SkBlendMode::kDstIn,
33     SkBlendMode::kSrcOut,
34     SkBlendMode::kDstOut,
35     SkBlendMode::kSrcATop,
36     SkBlendMode::kDstATop,
37     SkBlendMode::kXor,
38 };
39 
40 const int gWidth = 64;
41 const int gHeight = 64;
42 const SkScalar W = SkIntToScalar(gWidth);
43 const SkScalar H = SkIntToScalar(gHeight);
44 
drawCell(SkCanvas * canvas,SkBlendMode mode,SkAlpha a0,SkAlpha a1)45 static SkScalar drawCell(SkCanvas* canvas, SkBlendMode mode, SkAlpha a0, SkAlpha a1) {
46 
47     SkPaint paint;
48     paint.setAntiAlias(true);
49 
50     SkRect r = SkRect::MakeWH(W, H);
51     r.inset(W/10, H/10);
52 
53     paint.setColor(SK_ColorBLUE);
54     paint.setAlpha(a0);
55     canvas->drawOval(r, paint);
56 
57     paint.setColor(SK_ColorRED);
58     paint.setAlpha(a1);
59     paint.setBlendMode(mode);
60     for (int angle = 0; angle < 24; ++angle) {
61         SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
62         SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
63         paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
64         canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
65     }
66 
67     return H;
68 }
69 
make_bg_shader()70 static sk_sp<SkShader> make_bg_shader() {
71     SkBitmap bm;
72     bm.allocN32Pixels(2, 2);
73     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
74     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCE, 0xCF, 0xCE);
75 
76     SkMatrix m;
77     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
78     return bm.makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat, SkSamplingOptions(), m);
79 }
80 
81 namespace skiagm {
82 
83     class HairModesGM : public GM {
84         SkPaint fBGPaint;
85 
86     protected:
getName() const87         SkString getName() const override { return SkString("hairmodes"); }
88 
getISize()89         SkISize getISize() override { return SkISize::Make(640, 480); }
90 
onOnceBeforeDraw()91         void onOnceBeforeDraw() override {
92             fBGPaint.setShader(make_bg_shader());
93         }
94 
onDraw(SkCanvas * canvas)95         void onDraw(SkCanvas* canvas) override {
96             const SkRect bounds = SkRect::MakeWH(W, H);
97             constexpr SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
98 
99             canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
100 
101             for (int alpha = 0; alpha < 4; ++alpha) {
102                 canvas->save();
103                 canvas->save();
104                 for (size_t i = 0; i < std::size(gModes); ++i) {
105                     if (6 == i) {
106                         canvas->restore();
107                         canvas->translate(W * 5, 0);
108                         canvas->save();
109                     }
110 
111                     canvas->drawRect(bounds, fBGPaint);
112                     canvas->saveLayer(&bounds, nullptr);
113                     SkScalar dy = drawCell(canvas, gModes[i],
114                                            gAlphaValue[alpha & 1],
115                                            gAlphaValue[alpha & 2]);
116                     canvas->restore();
117 
118                     canvas->translate(0, dy * 5 / 4);
119                 }
120                 canvas->restore();
121                 canvas->restore();
122                 canvas->translate(W * 5 / 4, 0);
123             }
124         }
125 
126     private:
127         using INHERITED = GM;
128     };
129 
130     //////////////////////////////////////////////////////////////////////////////
131 
132     DEF_GM( return new HairModesGM; )
133 }  // namespace skiagm
134