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 #include "SkPath.h" 13 #include "SkRegion.h" 14 #include "SkShader.h" 15 #include "SkUtils.h" 16 #include "Sk1DPathEffect.h" 17 #include "SkCornerPathEffect.h" 18 #include "SkPathMeasure.h" 19 #include "SkRandom.h" 20 #include "SkColorPriv.h" 21 #include "SkColorFilter.h" 22 #include "SkDither.h" 23 24 static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) { 25 SkRect r; 26 SkPaint p; 27 28 p.setAntiAlias(true); 29 // p.setDither(true); 30 p.setStrokeWidth(SkIntToScalar(width/10)); 31 p.setStyle(SkPaint::kStroke_Style); 32 33 r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height)); 34 35 // SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN }; 36 SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 }; 37 SkShader* s = SkGradientShader::CreateSweep(r.centerX(), r.centerY(), 38 colors, nullptr, SK_ARRAY_COUNT(colors)); 39 p.setShader(s)->unref(); 40 41 SkAutoCanvasRestore acr(c, true); 42 43 c->translate(r.centerX(), r.centerY()); 44 c->rotate(angle); 45 c->translate(-r.centerX(), -r.centerY()); 46 47 SkRect bounds = r; 48 r.inset(p.getStrokeWidth(), p.getStrokeWidth()); 49 SkRect innerBounds = r; 50 51 if (true) { 52 c->drawOval(r, p); 53 } else { 54 SkScalar x = r.centerX(); 55 SkScalar y = r.centerY(); 56 SkScalar radius = r.width() / 2; 57 SkScalar thickness = p.getStrokeWidth(); 58 SkScalar sweep = 360.0f; 59 SkPath path; 60 61 path.moveTo(x + radius, y); 62 // outer top 63 path.lineTo(x + radius + thickness, y); 64 // outer arc 65 path.arcTo(bounds, 0, sweep, false); 66 // inner arc 67 path.arcTo(innerBounds, sweep, -sweep, false); 68 path.close(); 69 } 70 } 71 72 static void make_bm(SkBitmap* bm) { 73 bm->allocN32Pixels(100, 100); 74 bm->eraseColor(SK_ColorTRANSPARENT); 75 76 SkCanvas c(*bm); 77 draw_sweep(&c, bm->width(), bm->height(), 0); 78 } 79 80 static void pre_dither(const SkBitmap& bm) { 81 SkAutoLockPixels alp(bm); 82 83 for (int y = 0; y < bm.height(); y++) { 84 DITHER_4444_SCAN(y); 85 86 SkPMColor* p = bm.getAddr32(0, y); 87 for (int x = 0; x < bm.width(); x++) { 88 SkPMColor c = *p; 89 90 unsigned a = SkGetPackedA32(c); 91 unsigned r = SkGetPackedR32(c); 92 unsigned g = SkGetPackedG32(c); 93 unsigned b = SkGetPackedB32(c); 94 95 unsigned d = DITHER_VALUE(x); 96 97 a = SkDITHER_A32To4444(a, d); 98 r = SkDITHER_R32To4444(r, d); 99 g = SkDITHER_G32To4444(g, d); 100 b = SkDITHER_B32To4444(b, d); 101 102 a = SkA4444ToA32(a); 103 r = SkR4444ToR32(r); 104 g = SkG4444ToG32(g); 105 b = SkB4444ToB32(b); 106 107 *p++ = SkPackARGB32(a, r, g, b); 108 } 109 } 110 } 111 112 class DitherView : public SampleView { 113 public: 114 SkBitmap fBM, fBMPreDither, fBM16; 115 SkScalar fAngle; 116 117 DitherView() { 118 make_bm(&fBM); 119 make_bm(&fBMPreDither); 120 pre_dither(fBMPreDither); 121 fBM.copyTo(&fBM16, kARGB_4444_SkColorType); 122 123 fAngle = 0; 124 125 this->setBGColor(0xFF181818); 126 } 127 128 protected: 129 // overrides from SkEventSink 130 virtual bool onQuery(SkEvent* evt) { 131 if (SampleCode::TitleQ(*evt)) { 132 SampleCode::TitleR(evt, "Dither"); 133 return true; 134 } 135 return this->INHERITED::onQuery(evt); 136 } 137 138 virtual void onDrawContent(SkCanvas* canvas) { 139 SkPaint paint; 140 SkScalar x = SkIntToScalar(10); 141 SkScalar y = SkIntToScalar(10); 142 const SkScalar DX = SkIntToScalar(fBM.width() + 10); 143 144 paint.setAntiAlias(true); 145 146 if (true) { 147 canvas->drawBitmap(fBM, x, y, &paint); 148 x += DX; 149 paint.setDither(true); 150 canvas->drawBitmap(fBM, x, y, &paint); 151 152 x += DX; 153 paint.setDither(false); 154 canvas->drawBitmap(fBMPreDither, x, y, &paint); 155 156 x += DX; 157 canvas->drawBitmap(fBM16, x, y, &paint); 158 } 159 160 canvas->translate(DX, DX*2); 161 draw_sweep(canvas, fBM.width(), fBM.height(), fAngle); 162 canvas->translate(DX, 0); 163 draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle); 164 canvas->translate(DX, 0); 165 draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle); 166 167 fAngle += SK_Scalar1/2; 168 this->inval(nullptr); 169 } 170 171 private: 172 typedef SampleView INHERITED; 173 }; 174 175 ////////////////////////////////////////////////////////////////////////////// 176 177 static SkView* MyFactory() { return new DitherView; } 178 static SkViewRegister reg(MyFactory); 179
