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 "SampleCode.h" 9 #include "SkAnimTimer.h" 10 #include "SkCanvas.h" 11 #include "SkGradientShader.h" 12 #include "SkPatchUtils.h" 13 #include "SkPerlinNoiseShader.h" 14 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 SampleView { 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: 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: 113 // overrides from SkEventSink 114 bool onQuery(SkEvent* evt) override { 115 if (SampleCode::TitleQ(*evt)) { 116 SampleCode::TitleR(evt, "PerlinPatch"); 117 return true; 118 } 119 SkUnichar uni; 120 if (SampleCode::CharQ(*evt, &uni)) { 121 switch (uni) { 122 case 'g': fShowGrid = !fShowGrid; return true; 123 default: break; 124 } 125 } 126 return this->INHERITED::onQuery(evt); 127 } 128 129 bool onAnimate(const SkAnimTimer& timer) override { 130 fSeed += 0.005f; 131 return true; 132 } 133 134 135 void onDrawContent(SkCanvas* canvas) override { 136 if (!canvas->getTotalMatrix().invert(&fInvMatrix)) { 137 return; 138 } 139 140 SkPaint paint; 141 142 SkScalar texWidth = fTexScale * TexWidth; 143 SkScalar texHeight = fTexScale * TexHeight; 144 const SkPoint texCoords[SkPatchUtils::kNumCorners] = { 145 { fTexX - texWidth, fTexY - texHeight}, 146 { fTexX + texWidth, fTexY - texHeight}, 147 { fTexX + texWidth, fTexY + texHeight}, 148 { fTexX - texWidth, fTexY + texHeight}} 149 ; 150 151 SkScalar scaleFreq = 2.0; 152 fShader1 = SkPerlinNoiseShader::MakeImprovedNoise(fXFreq/scaleFreq, fYFreq/scaleFreq, 4, 153 fSeed); 154 fShaderCompose = SkShader::MakeComposeShader(fShader0, fShader1, SkBlendMode::kSrcOver); 155 156 paint.setShader(fShaderCompose); 157 158 const SkPoint* tex = texCoords; 159 if (fShowGrid) { 160 tex = nullptr; 161 } 162 canvas->drawPatch(fPts, nullptr, tex, SkBlendMode::kSrc, paint); 163 164 draw_control_points(canvas, fPts); 165 } 166 167 class PtClick : public Click { 168 public: 169 int fIndex; 170 PtClick(SkView* view, int index) : Click(view), fIndex(index) {} 171 }; 172 173 static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y) { 174 return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5); 175 } 176 177 SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { 178 // holding down shift 179 if (1 == modi) { 180 return new PtClick(this, -1); 181 } 182 // holding down ctrl 183 if (2 == modi) { 184 return new PtClick(this, -2); 185 } 186 SkPoint clickPoint = {x, y}; 187 fInvMatrix.mapPoints(&clickPoint, 1); 188 for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) { 189 if (hittest(fPts[i], clickPoint.fX, clickPoint.fY)) { 190 return new PtClick(this, (int)i); 191 } 192 } 193 return this->INHERITED::onFindClickHandler(x, y, modi); 194 } 195 196 bool onClick(Click* click) override { 197 PtClick* ptClick = (PtClick*)click; 198 if (ptClick->fIndex >= 0) { 199 fPts[ptClick->fIndex].set(click->fCurr.fX , click->fCurr.fY ); 200 } else if (-1 == ptClick->fIndex) { 201 SkScalar xDiff = click->fPrev.fX - click->fCurr.fX; 202 SkScalar yDiff = click->fPrev.fY - click->fCurr.fY; 203 fTexX += xDiff * fTexScale; 204 fTexY += yDiff * fTexScale; 205 } else if (-2 == ptClick->fIndex) { 206 SkScalar yDiff = click->fCurr.fY - click->fPrev.fY; 207 fTexScale += yDiff / 10.0f; 208 fTexScale = SkTMax(0.1f, SkTMin(20.f, fTexScale)); 209 } 210 return true; 211 } 212 213 private: 214 typedef SampleView INHERITED; 215 }; 216 217 DEF_SAMPLE( return new PerlinPatchView(); ) 218
