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