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 "SkRandom.h"
12
make_shader(SkScalar w,SkScalar h)13 static SkShader* make_shader(SkScalar w, SkScalar h) {
14 const SkColor colors[] = {
15 SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE,
16 SK_ColorMAGENTA, SK_ColorBLUE, SK_ColorYELLOW,
17 };
18 const SkPoint pts[] = { { w/4, 0 }, { 3*w/4, h } };
19
20 return SkGradientShader::CreateLinear(pts, colors, NULL,
21 SK_ARRAY_COUNT(colors),
22 SkShader::kMirror_TileMode);
23 }
24
25 class VerticesGM : public skiagm::GM {
26 SkPoint fPts[9];
27 SkPoint fTexs[9];
28 SkColor fColors[9];
29 SkShader* fShader;
30 unsigned fAlpha;
31
32 public:
VerticesGM(unsigned alpha)33 VerticesGM(unsigned alpha) : fShader(NULL), fAlpha(alpha) {
34 }
35
~VerticesGM()36 virtual ~VerticesGM() {
37 SkSafeUnref(fShader);
38 }
39
40 protected:
onGetFlags() const41 virtual uint32_t onGetFlags() const SK_OVERRIDE {
42 return kSkipTiled_Flag;
43 }
44
onOnceBeforeDraw()45 virtual void onOnceBeforeDraw() SK_OVERRIDE {
46 const SkScalar X = 150;
47 const SkScalar Y = 150;
48
49 fPts[0].set(0, 0); fPts[1].set(X/2, 10); fPts[2].set(X, 0);
50 fPts[3].set(10, Y/2); fPts[4].set(X/2, Y/2); fPts[5].set(X-10, Y/2);
51 fPts[6].set(0, Y); fPts[7].set(X/2, Y-10); fPts[8].set(X, Y);
52
53 const SkScalar w = 200;
54 const SkScalar h = 200;
55
56 fTexs[0].set(0, 0); fTexs[1].set(w/2, 0); fTexs[2].set(w, 0);
57 fTexs[3].set(0, h/2); fTexs[4].set(w/2, h/2); fTexs[5].set(w, h/2);
58 fTexs[6].set(0, h); fTexs[7].set(w/2, h); fTexs[8].set(w, h);
59
60 fShader = make_shader(w, h);
61
62 SkRandom rand;
63 for (size_t i = 0; i < SK_ARRAY_COUNT(fColors); ++i) {
64 fColors[i] = rand.nextU() | 0xFF000000;
65 }
66 }
67
onShortName()68 virtual SkString onShortName() SK_OVERRIDE {
69 SkString name("vertices");
70 if (0xFF != fAlpha) {
71 name.appendf("_%02X", fAlpha);
72 }
73 return name;
74 }
75
onISize()76 virtual SkISize onISize() SK_OVERRIDE {
77 return SkISize::Make(600, 600);
78 }
79
onDraw(SkCanvas * canvas)80 virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
81 // start with the center of a 3x3 grid
82 static const uint16_t fan[] = {
83 4,
84 0, 1, 2, 5, 8, 7, 6, 3, 0
85 };
86
87 const struct {
88 const SkColor* fColors;
89 const SkPoint* fTexs;
90 } rec[] = {
91 { fColors, NULL },
92 { NULL, fTexs },
93 { fColors, fTexs },
94 };
95
96 const SkXfermode::Mode modes[] = {
97 SkXfermode::kSrc_Mode,
98 SkXfermode::kDst_Mode,
99 SkXfermode::kModulate_Mode,
100 };
101
102 SkPaint paint;
103 paint.setShader(fShader);
104 paint.setAlpha(fAlpha);
105
106 canvas->translate(20, 20);
107 for (size_t j = 0; j < SK_ARRAY_COUNT(modes); ++j) {
108 SkXfermode* xfer = SkXfermode::Create(modes[j]);
109 canvas->save();
110 for (size_t i = 0; i < SK_ARRAY_COUNT(rec); ++i) {
111 canvas->drawVertices(SkCanvas::kTriangleFan_VertexMode,
112 SK_ARRAY_COUNT(fPts), fPts,
113 rec[i].fTexs, rec[i].fColors,
114 xfer, fan, SK_ARRAY_COUNT(fan), paint);
115 canvas->translate(200, 0);
116 }
117 canvas->restore();
118 canvas->translate(0, 200);
119 xfer->unref();
120 }
121 }
122
123 private:
124 typedef skiagm::GM INHERITED;
125 };
126
127 /////////////////////////////////////////////////////////////////////////////////////
128
129 DEF_GM( return SkNEW_ARGS(VerticesGM, (0xFF)); )
130 DEF_GM( return SkNEW_ARGS(VerticesGM, (0x80)); )
131