1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #include "SampleCode.h" 9 #include "SkView.h" 10 #include "SkCanvas.h" 11 #include "SkGradientShader.h" 12 13 static SkShader* setgrad(const SkRect& r, SkColor c0, SkColor c1) { 14 SkColor colors[] = { c0, c1 }; 15 SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fTop } }; 16 return SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode); 17 } 18 19 static void test_alphagradients(SkCanvas* canvas) { 20 SkRect r; 21 r.set(SkIntToScalar(10), SkIntToScalar(10), 22 SkIntToScalar(410), SkIntToScalar(30)); 23 SkPaint p, p2; 24 p2.setStyle(SkPaint::kStroke_Style); 25 26 p.setShader(setgrad(r, 0xFF00FF00, 0x0000FF00))->unref(); 27 canvas->drawRect(r, p); 28 canvas->drawRect(r, p2); 29 30 r.offset(0, r.height() + SkIntToScalar(4)); 31 p.setShader(setgrad(r, 0xFF00FF00, 0x00000000))->unref(); 32 canvas->drawRect(r, p); 33 canvas->drawRect(r, p2); 34 35 r.offset(0, r.height() + SkIntToScalar(4)); 36 p.setShader(setgrad(r, 0xFF00FF00, 0x00FF0000))->unref(); 37 canvas->drawRect(r, p); 38 canvas->drawRect(r, p2); 39 } 40 41 /////////////////////////////////////////////////////////////////////////////// 42 43 struct GradData { 44 int fCount; 45 const SkColor* fColors; 46 const SkScalar* fPos; 47 }; 48 49 static const SkColor gColors[] = { 50 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK 51 }; 52 static const SkScalar gPos0[] = { 0, SK_Scalar1 }; 53 static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 }; 54 static const SkScalar gPos2[] = { 55 0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1 56 }; 57 58 static const GradData gGradData[] = { 59 { 2, gColors, NULL }, 60 { 2, gColors, gPos0 }, 61 { 2, gColors, gPos1 }, 62 { 5, gColors, NULL }, 63 { 5, gColors, gPos2 } 64 }; 65 66 static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 67 return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos, data.fCount, tm); 68 } 69 70 static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 71 SkPoint center; 72 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 73 SkScalarAve(pts[0].fY, pts[1].fY)); 74 return SkGradientShader::CreateRadial(center, center.fX, data.fColors, 75 data.fPos, data.fCount, tm); 76 } 77 78 static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 79 SkPoint center; 80 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 81 SkScalarAve(pts[0].fY, pts[1].fY)); 82 return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount); 83 } 84 85 static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) { 86 SkPoint center0, center1; 87 center0.set(SkScalarAve(pts[0].fX, pts[1].fX), 88 SkScalarAve(pts[0].fY, pts[1].fY)); 89 center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5), 90 SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4)); 91 return SkGradientShader::CreateTwoPointRadial( 92 center1, (pts[1].fX - pts[0].fX) / 7, 93 center0, (pts[1].fX - pts[0].fX) / 2, 94 data.fColors, data.fPos, data.fCount, tm); 95 } 96 97 static SkShader* Make2RadialConcentric(const SkPoint pts[2], const GradData& data, 98 SkShader::TileMode tm) { 99 SkPoint center; 100 center.set(SkScalarAve(pts[0].fX, pts[1].fX), 101 SkScalarAve(pts[0].fY, pts[1].fY)); 102 return SkGradientShader::CreateTwoPointRadial( 103 center, (pts[1].fX - pts[0].fX) / 7, 104 center, (pts[1].fX - pts[0].fX) / 2, 105 data.fColors, data.fPos, data.fCount, tm); 106 } 107 108 typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm); 109 110 static const GradMaker gGradMakers[] = { 111 MakeLinear, MakeRadial, MakeSweep, Make2Radial, Make2RadialConcentric 112 }; 113 114 /////////////////////////////////////////////////////////////////////////////// 115 116 class GradientsView : public SampleView { 117 public: 118 GradientsView() { 119 this->setBGColor(0xFFDDDDDD); 120 } 121 122 protected: 123 // overrides from SkEventSink 124 virtual bool onQuery(SkEvent* evt) { 125 if (SampleCode::TitleQ(*evt)) { 126 SampleCode::TitleR(evt, "Gradients"); 127 return true; 128 } 129 return this->INHERITED::onQuery(evt); 130 } 131 132 virtual void onDrawContent(SkCanvas* canvas) { 133 SkPoint pts[2] = { 134 { 0, 0 }, 135 { SkIntToScalar(100), SkIntToScalar(100) } 136 }; 137 SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) }; 138 SkPaint paint; 139 paint.setDither(true); 140 141 canvas->save(); 142 canvas->translate(SkIntToScalar(20), SkIntToScalar(10)); 143 144 for (int tm = 0; tm < SkShader::kTileModeCount; ++tm) { 145 canvas->save(); 146 for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) { 147 canvas->save(); 148 for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) { 149 SkShader* shader; 150 shader = gGradMakers[j](pts, gGradData[i], (SkShader::TileMode)tm); 151 paint.setShader(shader)->unref(); 152 canvas->drawRect(r, paint); 153 canvas->translate(0, SkIntToScalar(120)); 154 } 155 canvas->restore(); 156 canvas->translate(SkIntToScalar(120), 0); 157 } 158 canvas->restore(); 159 canvas->translate(SK_ARRAY_COUNT(gGradData)*SkIntToScalar(120), 0); 160 } 161 canvas->restore(); 162 163 canvas->translate(0, SkIntToScalar(370)); 164 if (false) { // avoid bit rot, suppress warning 165 test_alphagradients(canvas); 166 } 167 this->inval(NULL); 168 } 169 170 private: 171 typedef SampleView INHERITED; 172 }; 173 174 /////////////////////////////////////////////////////////////////////////////// 175 176 static SkView* MyFactory() { return new GradientsView; } 177 static SkViewRegister reg(MyFactory); 178
