1 /*
2 * Copyright 2015 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 "SkGradientShader.h"
11 #include "SkImage.h"
12 #include "SkPath.h"
13 #include "SkSurface.h"
14
make_image(SkCanvas * origCanvas,int w,int h)15 static sk_sp<SkImage> make_image(SkCanvas* origCanvas, int w, int h) {
16 SkImageInfo info = SkImageInfo::MakeN32Premul(w, h);
17 auto surface(origCanvas->makeSurface(info));
18 if (nullptr == surface) {
19 surface = SkSurface::MakeRaster(info);
20 }
21 SkCanvas* canvas = surface->getCanvas();
22
23 sk_tool_utils::draw_checkerboard(canvas, SK_ColorRED, SK_ColorGREEN, w/10);
24 return surface->makeImageSnapshot();
25 }
26
27 namespace skiagm {
28
29 class PerspShadersGM : public GM {
30 public:
PerspShadersGM(bool doAA)31 PerspShadersGM(bool doAA) : fDoAA(doAA) { }
32
33 protected:
onShortName()34 SkString onShortName() override {
35 SkString name;
36 name.printf("persp_shaders_%s",
37 fDoAA ? "aa" : "bw");
38 return name;
39 }
40
onISize()41 SkISize onISize() override {
42 return SkISize::Make(kCellSize*kNumCols, kCellSize*kNumRows);
43 }
44
onOnceBeforeDraw()45 void onOnceBeforeDraw() override {
46 fBitmap = sk_tool_utils::create_checkerboard_bitmap(kCellSize, kCellSize,
47 SK_ColorBLUE, SK_ColorYELLOW,
48 kCellSize/10);
49
50 fBitmapShader = SkShader::MakeBitmapShader(fBitmap, SkShader::kClamp_TileMode,
51 SkShader::kClamp_TileMode);
52 SkPoint pts1[] = {
53 { 0, 0 },
54 { SkIntToScalar(kCellSize), SkIntToScalar(kCellSize) }
55 };
56 SkPoint pts2[] = {
57 { 0, 0 },
58 { 0, SkIntToScalar(kCellSize) }
59 };
60 constexpr SkColor colors[] = {
61 SK_ColorRED, SK_ColorGREEN, SK_ColorRED, SK_ColorGREEN, SK_ColorRED
62 };
63 constexpr SkScalar pos[] = { 0, 0.25f, 0.5f, 0.75f, SK_Scalar1 };
64
65 fLinearGrad1 = SkGradientShader::MakeLinear(pts1, colors, pos, SK_ARRAY_COUNT(colors),
66 SkShader::kClamp_TileMode);
67 fLinearGrad2 = SkGradientShader::MakeLinear(pts2, colors, pos, SK_ARRAY_COUNT(colors),
68 SkShader::kClamp_TileMode);
69
70 fPerspMatrix.reset();
71 fPerspMatrix.setPerspY(SK_Scalar1 / 50);
72
73 fPath.moveTo(0, 0);
74 fPath.lineTo(0, SkIntToScalar(kCellSize));
75 fPath.lineTo(kCellSize/2.0f, kCellSize/2.0f);
76 fPath.lineTo(SkIntToScalar(kCellSize), SkIntToScalar(kCellSize));
77 fPath.lineTo(SkIntToScalar(kCellSize), 0);
78 fPath.close();
79 }
80
drawRow(SkCanvas * canvas,SkFilterQuality filterQ)81 void drawRow(SkCanvas* canvas, SkFilterQuality filterQ) {
82 SkPaint filterPaint;
83 filterPaint.setFilterQuality(filterQ);
84 filterPaint.setAntiAlias(fDoAA);
85
86 SkPaint pathPaint;
87 pathPaint.setShader(fBitmapShader);
88 pathPaint.setFilterQuality(filterQ);
89 pathPaint.setAntiAlias(fDoAA);
90
91 SkPaint gradPaint1;
92 gradPaint1.setShader(fLinearGrad1);
93 gradPaint1.setAntiAlias(fDoAA);
94 SkPaint gradPaint2;
95 gradPaint2.setShader(fLinearGrad2);
96 gradPaint2.setAntiAlias(fDoAA);
97
98 SkRect r = SkRect::MakeWH(SkIntToScalar(kCellSize), SkIntToScalar(kCellSize));
99
100 canvas->save();
101
102 canvas->save();
103 canvas->concat(fPerspMatrix);
104 canvas->drawBitmapRect(fBitmap, r, &filterPaint);
105 canvas->restore();
106
107 canvas->translate(SkIntToScalar(kCellSize), 0);
108 canvas->save();
109 canvas->concat(fPerspMatrix);
110 canvas->drawImage(fImage.get(), 0, 0, &filterPaint);
111 canvas->restore();
112
113 canvas->translate(SkIntToScalar(kCellSize), 0);
114 canvas->save();
115 canvas->concat(fPerspMatrix);
116 canvas->drawRect(r, pathPaint);
117 canvas->restore();
118
119 canvas->translate(SkIntToScalar(kCellSize), 0);
120 canvas->save();
121 canvas->concat(fPerspMatrix);
122 canvas->drawPath(fPath, pathPaint);
123 canvas->restore();
124
125 canvas->translate(SkIntToScalar(kCellSize), 0);
126 canvas->save();
127 canvas->concat(fPerspMatrix);
128 canvas->drawRect(r, gradPaint1);
129 canvas->restore();
130
131 canvas->translate(SkIntToScalar(kCellSize), 0);
132 canvas->save();
133 canvas->concat(fPerspMatrix);
134 canvas->drawPath(fPath, gradPaint2);
135 canvas->restore();
136
137 canvas->restore();
138 }
139
onDraw(SkCanvas * canvas)140 void onDraw(SkCanvas* canvas) override {
141 if (!fImage) {
142 fImage = make_image(canvas, kCellSize, kCellSize);
143 }
144
145 this->drawRow(canvas, kNone_SkFilterQuality);
146 canvas->translate(0, SkIntToScalar(kCellSize));
147 this->drawRow(canvas, kLow_SkFilterQuality);
148 canvas->translate(0, SkIntToScalar(kCellSize));
149 this->drawRow(canvas, kMedium_SkFilterQuality);
150 canvas->translate(0, SkIntToScalar(kCellSize));
151 this->drawRow(canvas, kHigh_SkFilterQuality);
152 canvas->translate(0, SkIntToScalar(kCellSize));
153 }
154 private:
155 static constexpr int kCellSize = 50;
156 static constexpr int kNumRows = 4;
157 static constexpr int kNumCols = 6;
158
159 bool fDoAA;
160 SkPath fPath;
161 sk_sp<SkShader> fBitmapShader;
162 sk_sp<SkShader> fLinearGrad1;
163 sk_sp<SkShader> fLinearGrad2;
164 SkMatrix fPerspMatrix;
165 sk_sp<SkImage> fImage;
166 SkBitmap fBitmap;
167
168 typedef GM INHERITED;
169 };
170
171 //////////////////////////////////////////////////////////////////////////////
172
173 DEF_GM(return new PerspShadersGM(true);)
174 DEF_GM(return new PerspShadersGM(false);)
175 }
176