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 "Sample.h"
9 #include "SkAnimTimer.h"
10 #include "SkCanvas.h"
11 #include "SkGradientShader.h"
12 #include "SkPatchUtils.h"
13 #include "SkPerlinNoiseShader.h"
14
draw_control_points(SkCanvas * canvas,const SkPoint cubics[12])15 static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) {
16 //draw control points
17 SkPaint paint;
18 SkPoint bottom[SkPatchUtils::kNumPtsCubic];
19 SkPatchUtils::GetBottomCubic(cubics, bottom);
20 SkPoint top[SkPatchUtils::kNumPtsCubic];
21 SkPatchUtils::GetTopCubic(cubics, top);
22 SkPoint left[SkPatchUtils::kNumPtsCubic];
23 SkPatchUtils::GetLeftCubic(cubics, left);
24 SkPoint right[SkPatchUtils::kNumPtsCubic];
25 SkPatchUtils::GetRightCubic(cubics, right);
26
27 paint.setColor(SK_ColorBLACK);
28 paint.setStrokeWidth(0.5f);
29 SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
30 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
31 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom + 1, paint);
32 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
33 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
34 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
35
36 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top + 1, paint);
37 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left + 1, paint);
38 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right + 1, paint);
39
40 paint.setStrokeWidth(2);
41
42 paint.setColor(SK_ColorRED);
43 canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
44
45 paint.setColor(SK_ColorBLUE);
46 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint);
47
48 paint.setColor(SK_ColorCYAN);
49 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint);
50
51 paint.setColor(SK_ColorYELLOW);
52 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint);
53
54 paint.setColor(SK_ColorGREEN);
55 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint);
56 }
57
58 // These are actually half the total width and hieghts
59 const SkScalar TexWidth = 100.0f;
60 const SkScalar TexHeight = 100.0f;
61
62 class PerlinPatchView : public Sample {
63 sk_sp<SkShader> fShader0;
64 sk_sp<SkShader> fShader1;
65 sk_sp<SkShader> fShaderCompose;
66 SkScalar fXFreq;
67 SkScalar fYFreq;
68 SkScalar fSeed;
69 SkPoint fPts[SkPatchUtils::kNumCtrlPts];
70 SkScalar fTexX;
71 SkScalar fTexY;
72 SkScalar fTexScale;
73 SkMatrix fInvMatrix;
74 bool fShowGrid = false;
75
76 public:
PerlinPatchView()77 PerlinPatchView() : fXFreq(0.025f), fYFreq(0.025f), fSeed(0.0f),
78 fTexX(100.0), fTexY(50.0), fTexScale(1.0f) {
79 const SkScalar s = 2;
80 // The order of the colors and points is clockwise starting at upper-left corner.
81 //top points
82 fPts[0].set(100 * s, 100 * s);
83 fPts[1].set(150 * s, 50 * s);
84 fPts[2].set(250 * s, 150 * s);
85 fPts[3].set(300 * s, 100 * s);
86 //right points
87 fPts[4].set(275 * s, 150 * s);
88 fPts[5].set(350 * s, 250 * s);
89 //bottom points
90 fPts[6].set(300 * s, 300 * s);
91 fPts[7].set(250 * s, 250 * s);
92 //left points
93 fPts[8].set(150 * s, 350 * s);
94 fPts[9].set(100 * s, 300 * s);
95 fPts[10].set(50 * s, 250 * s);
96 fPts[11].set(150 * s, 150 * s);
97
98 const SkColor colors[SkPatchUtils::kNumCorners] = {
99 0xFF5555FF, 0xFF8888FF, 0xFFCCCCFF
100 };
101 const SkPoint points[2] = { SkPoint::Make(0.0f, 0.0f),
102 SkPoint::Make(100.0f, 100.0f) };
103 fShader0 = SkGradientShader::MakeLinear(points,
104 colors,
105 nullptr,
106 3,
107 SkShader::kMirror_TileMode,
108 0,
109 nullptr);
110 }
111
112 protected:
onQuery(Sample::Event * evt)113 bool onQuery(Sample::Event* evt) override {
114 if (Sample::TitleQ(*evt)) {
115 Sample::TitleR(evt, "PerlinPatch");
116 return true;
117 }
118 SkUnichar uni;
119 if (Sample::CharQ(*evt, &uni)) {
120 switch (uni) {
121 case 'g': fShowGrid = !fShowGrid; return true;
122 default: break;
123 }
124 }
125 return this->INHERITED::onQuery(evt);
126 }
127
onAnimate(const SkAnimTimer & timer)128 bool onAnimate(const SkAnimTimer& timer) override {
129 fSeed += 0.005f;
130 return true;
131 }
132
133
onDrawContent(SkCanvas * canvas)134 void onDrawContent(SkCanvas* canvas) override {
135 if (!canvas->getTotalMatrix().invert(&fInvMatrix)) {
136 return;
137 }
138
139 SkPaint paint;
140
141 SkScalar texWidth = fTexScale * TexWidth;
142 SkScalar texHeight = fTexScale * TexHeight;
143 const SkPoint texCoords[SkPatchUtils::kNumCorners] = {
144 { fTexX - texWidth, fTexY - texHeight},
145 { fTexX + texWidth, fTexY - texHeight},
146 { fTexX + texWidth, fTexY + texHeight},
147 { fTexX - texWidth, fTexY + texHeight}}
148 ;
149
150 SkScalar scaleFreq = 2.0;
151 fShader1 = SkPerlinNoiseShader::MakeImprovedNoise(fXFreq/scaleFreq, fYFreq/scaleFreq, 4,
152 fSeed);
153 fShaderCompose = SkShader::MakeComposeShader(fShader0, fShader1, SkBlendMode::kSrcOver);
154
155 paint.setShader(fShaderCompose);
156
157 const SkPoint* tex = texCoords;
158 if (fShowGrid) {
159 tex = nullptr;
160 }
161 canvas->drawPatch(fPts, nullptr, tex, SkBlendMode::kSrc, paint);
162
163 draw_control_points(canvas, fPts);
164 }
165
166 class PtClick : public Click {
167 public:
168 int fIndex;
PtClick(Sample * view,int index)169 PtClick(Sample* view, int index) : Click(view), fIndex(index) {}
170 };
171
hittest(const SkPoint & pt,SkScalar x,SkScalar y)172 static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y) {
173 return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5);
174 }
175
onFindClickHandler(SkScalar x,SkScalar y,unsigned modi)176 Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
177 // holding down shift
178 if (1 == modi) {
179 return new PtClick(this, -1);
180 }
181 // holding down ctrl
182 if (2 == modi) {
183 return new PtClick(this, -2);
184 }
185 SkPoint clickPoint = {x, y};
186 fInvMatrix.mapPoints(&clickPoint, 1);
187 for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) {
188 if (hittest(fPts[i], clickPoint.fX, clickPoint.fY)) {
189 return new PtClick(this, (int)i);
190 }
191 }
192 return this->INHERITED::onFindClickHandler(x, y, modi);
193 }
194
onClick(Click * click)195 bool onClick(Click* click) override {
196 PtClick* ptClick = (PtClick*)click;
197 if (ptClick->fIndex >= 0) {
198 fPts[ptClick->fIndex].set(click->fCurr.fX , click->fCurr.fY );
199 } else if (-1 == ptClick->fIndex) {
200 SkScalar xDiff = click->fPrev.fX - click->fCurr.fX;
201 SkScalar yDiff = click->fPrev.fY - click->fCurr.fY;
202 fTexX += xDiff * fTexScale;
203 fTexY += yDiff * fTexScale;
204 } else if (-2 == ptClick->fIndex) {
205 SkScalar yDiff = click->fCurr.fY - click->fPrev.fY;
206 fTexScale += yDiff / 10.0f;
207 fTexScale = SkTMax(0.1f, SkTMin(20.f, fTexScale));
208 }
209 return true;
210 }
211
212 private:
213 typedef Sample INHERITED;
214 };
215
216 DEF_SAMPLE( return new PerlinPatchView(); )
217