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.h"
9 #include "SkCanvas.h"
10 #include "SkGradientShader.h"
11 #include "SkLumaColorFilter.h"
12
13 static SkScalar kSize = 80;
14 static SkScalar kInset = 10;
15 static SkColor kColor1 = SkColorSetARGB(0xff, 0xff, 0xff, 0);
16 static SkColor kColor2 = SkColorSetARGB(0xff, 0x82, 0xff, 0);
17
draw_label(SkCanvas * canvas,const char * label,const SkPoint & offset)18 static void draw_label(SkCanvas* canvas, const char* label,
19 const SkPoint& offset) {
20 SkPaint paint;
21 sk_tool_utils::set_portable_typeface(&paint);
22 size_t len = strlen(label);
23
24 SkScalar width = paint.measureText(label, len);
25 canvas->drawText(label, len, offset.x() - width / 2, offset.y(),
26 paint);
27 }
28
draw_scene(SkCanvas * canvas,SkColorFilter * filter,SkXfermode::Mode mode,SkShader * s1,SkShader * s2)29 static void draw_scene(SkCanvas* canvas, SkColorFilter* filter,
30 SkXfermode::Mode mode, SkShader* s1,
31 SkShader* s2) {
32 SkPaint paint;
33 paint.setAntiAlias(true);
34 SkRect r, c, bounds = SkRect::MakeWH(kSize, kSize);
35
36 c = bounds;
37 c.fRight = bounds.centerX();
38 paint.setARGB(0x20, 0, 0, 0xff);
39 canvas->drawRect(bounds, paint);
40
41 canvas->saveLayer(&bounds, nullptr);
42
43 r = bounds;
44 r.inset(kInset, 0);
45 paint.setShader(s1);
46 paint.setColor(s1 ? SK_ColorBLACK : SkColorSetA(kColor1, 0x80));
47 canvas->drawOval(r, paint);
48 if (!s1) {
49 canvas->save();
50 canvas->clipRect(c);
51 paint.setColor(kColor1);
52 canvas->drawOval(r, paint);
53 canvas->restore();
54 }
55
56 SkPaint xferPaint;
57 xferPaint.setXfermodeMode(mode);
58 canvas->saveLayer(&bounds, &xferPaint);
59
60 r = bounds;
61 r.inset(0, kInset);
62 paint.setShader(s2);
63 paint.setColor(s2 ? SK_ColorBLACK : SkColorSetA(kColor2, 0x80));
64 paint.setColorFilter(filter);
65 canvas->drawOval(r, paint);
66 if (!s2) {
67 canvas->save();
68 canvas->clipRect(c);
69 paint.setColor(kColor2);
70 canvas->drawOval(r, paint);
71 canvas->restore();
72 }
73
74 canvas->restore();
75 canvas->restore();
76 }
77
78 class LumaFilterGM : public skiagm::GM {
79 public:
LumaFilterGM()80 LumaFilterGM() {
81 SkColor g1Colors[] = { kColor1, SkColorSetA(kColor1, 0x20) };
82 SkColor g2Colors[] = { kColor2, SkColorSetA(kColor2, 0x20) };
83 SkPoint g1Points[] = { { 0, 0 }, { 0, 100 } };
84 SkPoint g2Points[] = { { 0, 0 }, { kSize, 0 } };
85 SkScalar pos[] = { 0.2f, 1.0f };
86
87 fFilter.reset(SkLumaColorFilter::Create());
88 fGr1.reset(SkGradientShader::CreateLinear(g1Points,
89 g1Colors,
90 pos,
91 SK_ARRAY_COUNT(g1Colors),
92 SkShader::kClamp_TileMode));
93 fGr2.reset(SkGradientShader::CreateLinear(g2Points,
94 g2Colors,
95 pos,
96 SK_ARRAY_COUNT(g2Colors),
97 SkShader::kClamp_TileMode));
98 }
99
100 protected:
101
onShortName()102 SkString onShortName() override {
103 return SkString("lumafilter");
104 }
105
onISize()106 SkISize onISize() override {
107 return SkISize::Make(600, 420);
108 }
109
onDraw(SkCanvas * canvas)110 void onDraw(SkCanvas* canvas) override {
111 SkXfermode::Mode modes[] = { SkXfermode::kSrcOver_Mode,
112 SkXfermode::kDstOver_Mode,
113 SkXfermode::kSrcATop_Mode,
114 SkXfermode::kDstATop_Mode,
115 SkXfermode::kSrcIn_Mode,
116 SkXfermode::kDstIn_Mode,
117 };
118 struct {
119 SkShader* fShader1;
120 SkShader* fShader2;
121 } shaders[] = {
122 { nullptr, nullptr },
123 { nullptr, fGr2 },
124 { fGr1, nullptr },
125 { fGr1, fGr2 },
126 };
127
128 SkScalar gridStep = kSize + 2 * kInset;
129 for (size_t i = 0; i < SK_ARRAY_COUNT(modes); ++i) {
130 draw_label(canvas, SkXfermode::ModeName(modes[i]),
131 SkPoint::Make(gridStep * (0.5f + i), 20));
132 }
133
134 for (size_t i = 0; i < SK_ARRAY_COUNT(shaders); ++i) {
135 canvas->save();
136 canvas->translate(kInset, gridStep * i + 30);
137 for (size_t m = 0; m < SK_ARRAY_COUNT(modes); ++m) {
138 draw_scene(canvas, fFilter, modes[m], shaders[i].fShader1,
139 shaders[i].fShader2);
140 canvas->translate(gridStep, 0);
141 }
142 canvas->restore();
143 }
144 }
145
146 private:
147 SkAutoTUnref<SkColorFilter> fFilter;
148 SkAutoTUnref<SkShader> fGr1, fGr2;
149
150 typedef skiagm::GM INHERITED;
151 };
152
153 //////////////////////////////////////////////////////////////////////////////
154
155 DEF_GM(return new LumaFilterGM;)
156