1 /* 2 * Copyright 2011 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 #include "SampleCode.h" 8 #include "SkView.h" 9 #include "SkCanvas.h" 10 #include "SkGradientShader.h" 11 12 static sk_sp<SkShader> setgrad(const SkRect& r, SkColor c0, SkColor c1) { 13 SkColor colors[] = { c0, c1 }; 14 SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fTop } }; 15 return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode); 16 } 17 18 static void test_alphagradients(SkCanvas* canvas) { 19 SkRect r; 20 r.set(SkIntToScalar(10), SkIntToScalar(10), 21 SkIntToScalar(410), SkIntToScalar(30)); 22 SkPaint p, p2; 23 p2.setStyle(SkPaint::kStroke_Style); 24 25 p.setShader(setgrad(r, 0xFF00FF00, 0x0000FF00)); 26 canvas->drawRect(r, p); 27 canvas->drawRect(r, p2); 28 29 r.offset(0, r.height() + SkIntToScalar(4)); 30 p.setShader(setgrad(r, 0xFF00FF00, 0x00000000)); 31 canvas->drawRect(r, p); 32 canvas->drawRect(r, p2); 33 34 r.offset(0, r.height() + SkIntToScalar(4)); 35 p.setShader(setgrad(r, 0xFF00FF00, 0x00FF0000)); 36 canvas->drawRect(r, p); 37 canvas->drawRect(r, p2); 38 } 39 40 /////////////////////////////////////////////////////////////////////////////// 41 42 struct GradData { 43 int fCount; 44 const SkColor* fColors; 45 const SkScalar* fPos; 46 }; 47 48 static const SkColor gColors[] = { 49 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK 50 }; 51 static const SkScalar gPos0[] = { 0, SK_Scalar1 }; 52 static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 }; 53 static const SkScalar gPos2[] = { 54 0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1 55 }; 56 57 static const GradData gGradData[] = { 58 { 2, gColors, nullptr }, 59 { 2, gColors, gPos0 }, 60 { 2, gColors, gPos1 }, 61 { 5, gColors, nullptr }, 62 { 5, gColors, gPos2 } 63 }; 64 65 static sk_sp<SkShader> MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 66 return SkGradientShader::MakeLinear(pts, data.fColors, data.fPos, data.fCount, tm); 67 } 68 69 static sk_sp<SkShader> MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 70 SkPoint center; 71 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 72 SkScalarAve(pts[0].fY, pts[1].fY)); 73 return SkGradientShader::MakeRadial(center, center.fX, data.fColors, 74 data.fPos, data.fCount, tm); 75 } 76 77 static sk_sp<SkShader> MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 78 SkPoint center; 79 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 80 SkScalarAve(pts[0].fY, pts[1].fY)); 81 return SkGradientShader::MakeSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount); 82 } 83 84 static sk_sp<SkShader> Make2Conical(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 85 SkPoint center0, center1; 86 center0.set(SkScalarAve(pts[0].fX, pts[1].fX), 87 SkScalarAve(pts[0].fY, pts[1].fY)); 88 center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5), 89 SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4)); 90 return SkGradientShader::MakeTwoPointConical( 91 center1, (pts[1].fX - pts[0].fX) / 7, 92 center0, (pts[1].fX - pts[0].fX) / 2, 93 data.fColors, data.fPos, data.fCount, tm); 94 } 95 96 static sk_sp<SkShader> Make2ConicalConcentric(const SkPoint pts[2], const GradData& data, 97 SkShader::TileMode tm) { 98 SkPoint center; 99 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 100 SkScalarAve(pts[0].fY, pts[1].fY)); 101 return SkGradientShader::MakeTwoPointConical( 102 center, (pts[1].fX - pts[0].fX) / 7, 103 center, (pts[1].fX - pts[0].fX) / 2, 104 data.fColors, data.fPos, data.fCount, tm); 105 } 106 107 typedef sk_sp<SkShader> (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm); 108 109 static const GradMaker gGradMakers[] = { 110 MakeLinear, MakeRadial, MakeSweep, Make2Conical, Make2ConicalConcentric 111 }; 112 113 /////////////////////////////////////////////////////////////////////////////// 114 115 class GradientsView : public SampleView { 116 public: 117 GradientsView() { 118 this->setBGColor(0xFFDDDDDD); 119 } 120 121 protected: 122 bool onQuery(SkEvent* evt) override { 123 if (SampleCode::TitleQ(*evt)) { 124 SampleCode::TitleR(evt, "Gradients"); 125 return true; 126 } 127 return this->INHERITED::onQuery(evt); 128 } 129 130 void onDrawContent(SkCanvas* canvas) override { 131 SkPoint pts[2] = { 132 { 0, 0 }, 133 { SkIntToScalar(100), SkIntToScalar(100) } 134 }; 135 SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) }; 136 SkPaint paint; 137 paint.setDither(true); 138 139 canvas->save(); 140 canvas->translate(SkIntToScalar(20), SkIntToScalar(10)); 141 142 for (int tm = 0; tm < SkShader::kTileModeCount; ++tm) { 143 canvas->save(); 144 for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) { 145 canvas->save(); 146 for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) { 147 paint.setShader(gGradMakers[j](pts, gGradData[i], (SkShader::TileMode)tm)); 148 canvas->drawRect(r, paint); 149 canvas->translate(0, SkIntToScalar(120)); 150 } 151 canvas->restore(); 152 canvas->translate(SkIntToScalar(120), 0); 153 } 154 canvas->restore(); 155 canvas->translate(SK_ARRAY_COUNT(gGradData)*SkIntToScalar(120), 0); 156 } 157 canvas->restore(); 158 159 canvas->translate(0, SkIntToScalar(370)); 160 if (false) { // avoid bit rot, suppress warning 161 test_alphagradients(canvas); 162 } 163 this->inval(nullptr); 164 } 165 166 private: 167 typedef SampleView INHERITED; 168 }; 169 170 /////////////////////////////////////////////////////////////////////////////// 171 172 static SkView* MyFactory() { return new GradientsView; } 173 static SkViewRegister reg(MyFactory); 174
