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