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 "SkPath.h" 11 #include "SkRandom.h" 12 #include "SkScalar.h" 13 #include "SkTArray.h" 14 15 namespace skiagm { 16 17 // This GM tests a grab-bag of convex and concave polygons. They are triangles, 18 // trapezoid, diamond, polygons with lots of edges, several concave polygons... 19 // But rectangles are excluded. 20 class PolygonsGM: public GM { 21 public: 22 PolygonsGM() {} 23 24 protected: 25 26 SkString onShortName() override { 27 return SkString("polygons"); 28 } 29 30 SkISize onISize() override { 31 int width = kNumPolygons * kCellSize + 40; 32 int height = (kNumJoins * kNumStrokeWidths + kNumExtraStyles) * kCellSize + 40; 33 return SkISize::Make(width, height); 34 } 35 36 // Construct all polygons 37 void onOnceBeforeDraw() override { 38 SkPoint p0[] = {{0, 0}, {60, 0}, {90, 40}}; // triangle 39 SkPoint p1[] = {{0, 0}, {0, 40}, {60, 40}, {40, 0}}; // trapezoid 40 SkPoint p2[] = {{0, 0}, {40, 40}, {80, 40}, {40, 0}}; // diamond 41 SkPoint p3[] = {{10, 0}, {50, 0}, {60, 10}, {60, 30}, {50, 40}, 42 {10, 40}, {0, 30}, {0, 10}}; // octagon 43 SkPoint p4[32]; // circle-like polygons with 32-edges. 44 SkPoint p5[] = {{0, 0}, {20, 20}, {0, 40}, {60, 20}}; // concave polygon with 4 edges 45 SkPoint p6[] = {{0, 40}, {0, 30}, {15, 30}, {15, 20}, {30, 20}, 46 {30, 10}, {45, 10}, {45, 0}, {60, 0}, {60, 40}}; // stairs-like polygon 47 SkPoint p7[] = {{0, 20}, {20, 20}, {30, 0}, {40, 20}, {60, 20}, 48 {45, 30}, {55, 50}, {30, 40}, {5, 50}, {15, 30}}; // five-point stars 49 50 for (size_t i = 0; i < SK_ARRAY_COUNT(p4); ++i) { 51 SkScalar angle = 2 * SK_ScalarPI * i / SK_ARRAY_COUNT(p4); 52 p4[i].set(20 * SkScalarCos(angle) + 20, 20 * SkScalarSin(angle) + 20); 53 } 54 55 struct Polygons { 56 SkPoint* fPoints; 57 size_t fPointNum; 58 } pgs[] = { 59 { p0, SK_ARRAY_COUNT(p0) }, 60 { p1, SK_ARRAY_COUNT(p1) }, 61 { p2, SK_ARRAY_COUNT(p2) }, 62 { p3, SK_ARRAY_COUNT(p3) }, 63 { p4, SK_ARRAY_COUNT(p4) }, 64 { p5, SK_ARRAY_COUNT(p5) }, 65 { p6, SK_ARRAY_COUNT(p6) }, 66 { p7, SK_ARRAY_COUNT(p7) } 67 }; 68 69 SkASSERT(SK_ARRAY_COUNT(pgs) == kNumPolygons); 70 for (size_t pgIndex = 0; pgIndex < SK_ARRAY_COUNT(pgs); ++pgIndex) { 71 fPolygons.push_back().moveTo(pgs[pgIndex].fPoints[0].fX, 72 pgs[pgIndex].fPoints[0].fY); 73 for (size_t ptIndex = 1; ptIndex < pgs[pgIndex].fPointNum; ++ptIndex) { 74 fPolygons.back().lineTo(pgs[pgIndex].fPoints[ptIndex].fX, 75 pgs[pgIndex].fPoints[ptIndex].fY); 76 } 77 fPolygons.back().close(); 78 } 79 } 80 81 // Set the location for the current test on the canvas 82 static void SetLocation(SkCanvas* canvas, int counter, int lineNum) { 83 SkScalar x = SK_Scalar1 * kCellSize * (counter % lineNum) + 30 + SK_Scalar1 / 4; 84 SkScalar y = SK_Scalar1 * kCellSize * (counter / lineNum) + 30 + 3 * SK_Scalar1 / 4; 85 canvas->translate(x, y); 86 } 87 88 static void SetColorAndAlpha(SkPaint* paint, SkRandom* rand) { 89 SkColor color = rand->nextU(); 90 color |= 0xff000000; 91 paint->setColor(color); 92 if (40 == paint->getStrokeWidth()) { 93 paint->setAlpha(0xA0); 94 } 95 } 96 97 void onDraw(SkCanvas* canvas) override { 98 // Stroke widths are: 99 // 0(may use hairline rendering), 10(common case for stroke-style) 100 // 40(>= geometry width/height, make the contour filled in fact) 101 constexpr int kStrokeWidths[] = {0, 10, 40}; 102 SkASSERT(kNumStrokeWidths == SK_ARRAY_COUNT(kStrokeWidths)); 103 104 constexpr SkPaint::Join kJoins[] = { 105 SkPaint::kMiter_Join, SkPaint::kRound_Join, SkPaint::kBevel_Join 106 }; 107 SkASSERT(kNumJoins == SK_ARRAY_COUNT(kJoins)); 108 109 int counter = 0; 110 SkPaint paint; 111 paint.setAntiAlias(true); 112 113 SkRandom rand; 114 // For stroke style painter 115 paint.setStyle(SkPaint::kStroke_Style); 116 for (int join = 0; join < kNumJoins; ++join) { 117 for (int width = 0; width < kNumStrokeWidths; ++width) { 118 for (int i = 0; i < fPolygons.count(); ++i) { 119 canvas->save(); 120 SetLocation(canvas, counter, fPolygons.count()); 121 122 SetColorAndAlpha(&paint, &rand); 123 paint.setStrokeJoin(kJoins[join]); 124 paint.setStrokeWidth(SkIntToScalar(kStrokeWidths[width])); 125 126 canvas->drawPath(fPolygons[i], paint); 127 canvas->restore(); 128 ++counter; 129 } 130 } 131 } 132 133 // For stroke-and-fill style painter and fill style painter 134 constexpr SkPaint::Style kStyles[] = { 135 SkPaint::kStrokeAndFill_Style, SkPaint::kFill_Style 136 }; 137 SkASSERT(kNumExtraStyles == SK_ARRAY_COUNT(kStyles)); 138 139 paint.setStrokeJoin(SkPaint::kMiter_Join); 140 paint.setStrokeWidth(SkIntToScalar(20)); 141 for (int style = 0; style < kNumExtraStyles; ++style) { 142 paint.setStyle(kStyles[style]); 143 for (int i = 0; i < fPolygons.count(); ++i) { 144 canvas->save(); 145 SetLocation(canvas, counter, fPolygons.count()); 146 SetColorAndAlpha(&paint, &rand); 147 canvas->drawPath(fPolygons[i], paint); 148 canvas->restore(); 149 ++counter; 150 } 151 } 152 } 153 154 private: 155 static constexpr int kNumPolygons = 8; 156 static constexpr int kCellSize = 100; 157 static constexpr int kNumExtraStyles = 2; 158 static constexpr int kNumStrokeWidths = 3; 159 static constexpr int kNumJoins = 3; 160 161 SkTArray<SkPath> fPolygons; 162 typedef GM INHERITED; 163 }; 164 165 ////////////////////////////////////////////////////////////////////////////// 166 167 DEF_GM(return new PolygonsGM;) 168 169 } 170
