1/*
2 * Copyright 2014 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 "SkGradientShader.h"
10#include "SkPatchUtils.h"
11
12static sk_sp<SkShader> make_shader() {
13    const SkColor colors[] = {
14        SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE, SK_ColorMAGENTA, SK_ColorBLUE,
15        SK_ColorYELLOW,
16    };
17    const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } };
18
19    return SkGradientShader::MakeLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
20                                        SkShader::kMirror_TileMode);
21}
22
23static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) {
24    //draw control points
25    SkPaint paint;
26    SkPoint bottom[SkPatchUtils::kNumPtsCubic];
27    SkPatchUtils::getBottomCubic(cubics, bottom);
28    SkPoint top[SkPatchUtils::kNumPtsCubic];
29    SkPatchUtils::getTopCubic(cubics, top);
30    SkPoint left[SkPatchUtils::kNumPtsCubic];
31    SkPatchUtils::getLeftCubic(cubics, left);
32    SkPoint right[SkPatchUtils::kNumPtsCubic];
33    SkPatchUtils::getRightCubic(cubics, right);
34
35    paint.setColor(SK_ColorBLACK);
36    paint.setStrokeWidth(0.5f);
37    SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
38    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
39    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom + 1, paint);
40    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
41    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
42    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
43
44    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top + 1, paint);
45    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left + 1, paint);
46    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right + 1, paint);
47
48    paint.setStrokeWidth(2);
49
50    paint.setColor(SK_ColorRED);
51    canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
52
53    paint.setColor(SK_ColorBLUE);
54    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint);
55
56    paint.setColor(SK_ColorCYAN);
57    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint);
58
59    paint.setColor(SK_ColorYELLOW);
60    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint);
61
62    paint.setColor(SK_ColorGREEN);
63    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint);
64}
65
66DEF_SIMPLE_GM(patch_primitive, canvas, 1500, 1100) {
67        SkPaint paint;
68
69        // The order of the colors and points is clockwise starting at upper-left corner.
70        const SkPoint cubics[SkPatchUtils::kNumCtrlPts] = {
71            //top points
72            {100,100},{150,50},{250,150}, {300,100},
73            //right points
74            {250, 150},{350,250},
75            //bottom points
76            {300,300},{250,250},{150,350},{100,300},
77            //left points
78            {50,250},{150,150}
79        };
80
81        const SkColor colors[SkPatchUtils::kNumCorners] = {
82            SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
83        };
84        const SkPoint texCoords[SkPatchUtils::kNumCorners] = {
85            {0.0f, 0.0f}, {100.0f, 0.0f}, {100.0f,100.0f}, {0.0f, 100.0f}}
86        ;
87
88        const SkBlendMode modes[] = {
89            SkBlendMode::kSrc,
90            SkBlendMode::kDst,
91            SkBlendMode::kModulate,
92        };
93
94        sk_sp<SkShader> shader(make_shader());
95
96        canvas->save();
97        for (int y = 0; y < 3; y++) {
98            for (int x = 0; x < 4; x++) {
99                canvas->save();
100                canvas->translate(x * 350.0f, y * 350.0f);
101                switch (x) {
102                    case 0:
103                        canvas->drawPatch(cubics, nullptr, nullptr, modes[y], paint);
104                        break;
105                    case 1:
106                        canvas->drawPatch(cubics, colors, nullptr, modes[y], paint);
107                        break;
108                    case 2:
109                        paint.setShader(shader);
110                        canvas->drawPatch(cubics, nullptr, texCoords, modes[y], paint);
111                        paint.setShader(nullptr);
112                        break;
113                    case 3:
114                        paint.setShader(shader);
115                        canvas->drawPatch(cubics, colors, texCoords, modes[y], paint);
116                        paint.setShader(nullptr);
117                        break;
118                    default:
119                        break;
120                }
121
122                draw_control_points(canvas, cubics);
123                canvas->restore();
124            }
125        }
126        canvas->restore();
127}
128