1
2 /*
3 * Copyright 2014 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9 #include "gm.h"
10 #include "SkGradientShader.h"
11 #include "SkPatchUtils.h"
12
make_shader()13 static SkShader* make_shader() {
14 const SkColor colors[] = {
15 SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE, SK_ColorMAGENTA, SK_ColorBLUE,
16 SK_ColorYELLOW,
17 };
18 const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } };
19
20 return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
21 SkShader::kMirror_TileMode);
22 }
23
draw_control_points(SkCanvas * canvas,const SkPoint cubics[12])24 static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) {
25 //draw control points
26 SkPaint paint;
27 SkPoint bottom[SkPatchUtils::kNumPtsCubic];
28 SkPatchUtils::getBottomCubic(cubics, bottom);
29 SkPoint top[SkPatchUtils::kNumPtsCubic];
30 SkPatchUtils::getTopCubic(cubics, top);
31 SkPoint left[SkPatchUtils::kNumPtsCubic];
32 SkPatchUtils::getLeftCubic(cubics, left);
33 SkPoint right[SkPatchUtils::kNumPtsCubic];
34 SkPatchUtils::getRightCubic(cubics, right);
35
36 paint.setColor(SK_ColorBLACK);
37 paint.setStrokeWidth(0.5f);
38 SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
39 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
40 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom + 1, paint);
41 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
42 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
43 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
44
45 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top + 1, paint);
46 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left + 1, paint);
47 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right + 1, paint);
48
49 paint.setStrokeWidth(2);
50
51 paint.setColor(SK_ColorRED);
52 canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
53
54 paint.setColor(SK_ColorBLUE);
55 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint);
56
57 paint.setColor(SK_ColorCYAN);
58 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint);
59
60 paint.setColor(SK_ColorYELLOW);
61 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint);
62
63 paint.setColor(SK_ColorGREEN);
64 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint);
65 }
66
67 namespace skiagm {
68 /**
69 * This GM draws a cubics coons patch using the specialized call SkCanvas::drawPatch.
70 */
71 class SkPatchGM : public GM {
72
73 public:
SkPatchGM()74 SkPatchGM() {
75 this->setBGColor(0xFFFFFFFF);
76 }
77
78 protected:
onShortName()79 SkString onShortName() override {
80 return SkString("patch_primitive");
81 }
82
onISize()83 SkISize onISize() override {
84 return SkISize::Make(800, 800);
85 }
86
onDraw(SkCanvas * canvas)87 void onDraw(SkCanvas* canvas) override {
88
89 SkPaint paint;
90
91 // The order of the colors and points is clockwise starting at upper-left corner.
92 const SkPoint cubics[SkPatchUtils::kNumCtrlPts] = {
93 //top points
94 {100,100},{150,50},{250,150}, {300,100},
95 //right points
96 {250, 150},{350,250},
97 //bottom points
98 {300,300},{250,250},{150,350},{100,300},
99 //left points
100 {50,250},{150,150}
101 };
102
103 const SkColor colors[SkPatchUtils::kNumCorners] = {
104 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
105 };
106 const SkPoint texCoords[SkPatchUtils::kNumCorners] = {
107 {0.0f, 0.0f}, {100.0f, 0.0f}, {100.0f,100.0f}, {0.0f, 100.0f}}
108 ;
109
110 const SkXfermode::Mode modes[] = {
111 SkXfermode::kSrc_Mode,
112 SkXfermode::kDst_Mode,
113 SkXfermode::kModulate_Mode,
114 };
115
116 SkAutoTUnref<SkShader> shader(make_shader());
117
118 canvas->save();
119 for (int y = 0; y < 3; y++) {
120 SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(modes[y]));
121
122 for (int x = 0; x < 4; x++) {
123 canvas->save();
124 canvas->translate(x * 350.0f, y * 350.0f);
125 switch (x) {
126 case 0:
127 canvas->drawPatch(cubics, NULL, NULL, xfer, paint);
128 break;
129 case 1:
130 canvas->drawPatch(cubics, colors, NULL, xfer, paint);
131 break;
132 case 2:
133 paint.setShader(shader);
134 canvas->drawPatch(cubics, NULL, texCoords, xfer, paint);
135 paint.setShader(NULL);
136 break;
137 case 3:
138 paint.setShader(shader);
139 canvas->drawPatch(cubics, colors, texCoords, xfer, paint);
140 paint.setShader(NULL);
141 break;
142 default:
143 break;
144 }
145
146 draw_control_points(canvas, cubics);
147 canvas->restore();
148 }
149 }
150 canvas->restore();
151 }
152
153 private:
154 typedef GM INHERITED;
155 };
156
157 DEF_GM(return SkNEW(SkPatchGM); )
158
159 }
160