1 // Copyright (C) 2013 Google Inc. All rights reserved. 2 // 3 // Redistribution and use in source and binary forms, with or without 4 // modification, are permitted provided that the following conditions are 5 // met: 6 // 7 // * Redistributions of source code must retain the above copyright 8 // notice, this list of conditions and the following disclaimer. 9 // * Redistributions in binary form must reproduce the above 10 // copyright notice, this list of conditions and the following disclaimer 11 // in the documentation and/or other materials provided with the 12 // distribution. 13 // * Neither the name of Google Inc. nor the names of its 14 // contributors may be used to endorse or promote products derived from 15 // this software without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 #include "config.h" 30 #include "platform/graphics/StrokeData.h" 31 #include "wtf/OwnPtr.h" 32 #include "wtf/PassOwnPtr.h" 33 34 namespace WebCore { 35 36 static const int dashRatio = 3; // Ratio of the length of a dash to its width. 37 38 void StrokeData::setLineDash(const DashArray& dashes, float dashOffset) 39 { 40 // FIXME: This is lifted directly off SkiaSupport, lines 49-74 41 // so it is not guaranteed to work correctly. 42 size_t dashLength = dashes.size(); 43 if (!dashLength) { 44 // If no dash is set, revert to solid stroke 45 // FIXME: do we need to set NoStroke in some cases? 46 m_style = SolidStroke; 47 m_dash.clear(); 48 return; 49 } 50 51 size_t count = !(dashLength % 2) ? dashLength : dashLength * 2; 52 OwnPtr<SkScalar[]> intervals = adoptArrayPtr(new SkScalar[count]); 53 54 for (unsigned i = 0; i < count; i++) 55 intervals[i] = dashes[i % dashLength]; 56 57 m_dash = adoptRef(SkDashPathEffect::Create(intervals.get(), count, dashOffset)); 58 } 59 60 void StrokeData::setupPaint(SkPaint* paint, int length) const 61 { 62 paint->setStyle(SkPaint::kStroke_Style); 63 paint->setStrokeWidth(SkFloatToScalar(m_thickness)); 64 paint->setStrokeCap(m_lineCap); 65 paint->setStrokeJoin(m_lineJoin); 66 paint->setStrokeMiter(SkFloatToScalar(m_miterLimit)); 67 68 setupPaintDashPathEffect(paint, length); 69 } 70 71 void StrokeData::setupPaintDashPathEffect(SkPaint* paint, int length) const 72 { 73 float width = m_thickness; 74 if (m_dash) { 75 paint->setPathEffect(m_dash.get()); 76 } else { 77 switch (m_style) { 78 case NoStroke: 79 case SolidStroke: 80 case DoubleStroke: 81 case WavyStroke: // FIXME: https://code.google.com/p/chromium/issues/detail?id=229574 82 paint->setPathEffect(0); 83 return; 84 case DashedStroke: 85 width = dashRatio * width; 86 // Fall through. 87 case DottedStroke: 88 // Truncate the width, since we don't want fuzzy dots or dashes. 89 int dashLength = static_cast<int>(width); 90 // Subtract off the endcaps, since they're rendered separately. 91 int distance = length - 2 * static_cast<int>(m_thickness); 92 int phase = 1; 93 if (dashLength > 1) { 94 // Determine how many dashes or dots we should have. 95 int numDashes = distance / dashLength; 96 int remainder = distance % dashLength; 97 // Adjust the phase to center the dashes within the line. 98 if (numDashes % 2) { 99 // Odd: shift right a full dash, minus half the remainder. 100 phase = dashLength - remainder / 2; 101 } else { 102 // Even: shift right half a dash, minus half the remainder. 103 phase = (dashLength - remainder) / 2; 104 } 105 } 106 SkScalar dashLengthSk = SkIntToScalar(dashLength); 107 SkScalar intervals[2] = { dashLengthSk, dashLengthSk }; 108 RefPtr<SkDashPathEffect> pathEffect = adoptRef(SkDashPathEffect::Create(intervals, 2, SkIntToScalar(phase))); 109 paint->setPathEffect(pathEffect.get()); 110 } 111 } 112 } 113 114 } // namespace 115