1/* 2 * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above 9 * copyright notice, this list of conditions and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following 13 * disclaimer in the documentation and/or other materials 14 * provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 20 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 27 * OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30#include "config.h" 31#include "RasterShape.h" 32 33#include <wtf/MathExtras.h> 34 35namespace WebCore { 36 37class MarginIntervalGenerator { 38public: 39 MarginIntervalGenerator(unsigned radius); 40 void set(int y, const IntShapeInterval&); 41 IntShapeInterval intervalAt(int y) const; 42 43private: 44 Vector<int> m_xIntercepts; 45 int m_y; 46 int m_x1; 47 int m_x2; 48}; 49 50MarginIntervalGenerator::MarginIntervalGenerator(unsigned radius) 51 : m_y(0) 52 , m_x1(0) 53 , m_x2(0) 54{ 55 m_xIntercepts.resize(radius + 1); 56 unsigned radiusSquared = radius * radius; 57 for (unsigned y = 0; y <= radius; y++) 58 m_xIntercepts[y] = sqrt(static_cast<double>(radiusSquared - y * y)); 59} 60 61void MarginIntervalGenerator::set(int y, const IntShapeInterval& interval) 62{ 63 ASSERT(y >= 0 && interval.x1() >= 0); 64 m_y = y; 65 m_x1 = interval.x1(); 66 m_x2 = interval.x2(); 67} 68 69IntShapeInterval MarginIntervalGenerator::intervalAt(int y) const 70{ 71 unsigned xInterceptsIndex = abs(y - m_y); 72 int dx = (xInterceptsIndex >= m_xIntercepts.size()) ? 0 : m_xIntercepts[xInterceptsIndex]; 73 return IntShapeInterval(m_x1 - dx, m_x2 + dx); 74} 75 76std::unique_ptr<RasterShapeIntervals> RasterShapeIntervals::computeShapeMarginIntervals(int shapeMargin) const 77{ 78 int marginIntervalsSize = (offset() > shapeMargin) ? size() : size() - offset() * 2 + shapeMargin * 2; 79 auto result = std::make_unique<RasterShapeIntervals>(marginIntervalsSize, std::max(shapeMargin, offset())); 80 MarginIntervalGenerator marginIntervalGenerator(shapeMargin); 81 82 for (int y = bounds().y(); y < bounds().maxY(); ++y) { 83 const IntShapeInterval& intervalAtY = intervalAt(y); 84 if (intervalAtY.isEmpty()) 85 continue; 86 87 marginIntervalGenerator.set(y, intervalAtY); 88 int marginY0 = std::max(minY(), y - shapeMargin); 89 int marginY1 = std::min(maxY(), y + shapeMargin + 1); 90 91 for (int marginY = y - 1; marginY >= marginY0; --marginY) { 92 if (marginY > bounds().y() && intervalAt(marginY).contains(intervalAtY)) 93 break; 94 result->intervalAt(marginY).unite(marginIntervalGenerator.intervalAt(marginY)); 95 } 96 97 result->intervalAt(y).unite(marginIntervalGenerator.intervalAt(y)); 98 99 for (int marginY = y + 1; marginY < marginY1; ++marginY) { 100 if (marginY < bounds().maxY() && intervalAt(marginY).contains(intervalAtY)) 101 break; 102 result->intervalAt(marginY).unite(marginIntervalGenerator.intervalAt(marginY)); 103 } 104 } 105 106 result->initializeBounds(); 107 return result; 108} 109 110void RasterShapeIntervals::initializeBounds() 111{ 112 m_bounds = IntRect(); 113 for (int y = minY(); y < maxY(); ++y) { 114 const IntShapeInterval& intervalAtY = intervalAt(y); 115 if (intervalAtY.isEmpty()) 116 continue; 117 m_bounds.unite(IntRect(intervalAtY.x1(), y, intervalAtY.width(), 1)); 118 } 119} 120 121void RasterShapeIntervals::buildBoundsPath(Path& path) const 122{ 123 for (int y = bounds().y(); y < bounds().maxY(); y++) { 124 if (intervalAt(y).isEmpty()) 125 continue; 126 127 IntShapeInterval extent = intervalAt(y); 128 int endY = y + 1; 129 for (; endY < bounds().maxY(); endY++) { 130 if (intervalAt(endY).isEmpty() || intervalAt(endY) != extent) 131 break; 132 } 133 path.addRect(FloatRect(extent.x1(), y, extent.width(), endY - y)); 134 y = endY - 1; 135 } 136} 137 138const RasterShapeIntervals& RasterShape::marginIntervals() const 139{ 140 ASSERT(shapeMargin() >= 0); 141 if (!shapeMargin()) 142 return *m_intervals; 143 144 int shapeMarginInt = clampToPositiveInteger(ceil(shapeMargin())); 145 int maxShapeMarginInt = std::max(m_marginRectSize.width(), m_marginRectSize.height()) * sqrt(2); 146 if (!m_marginIntervals) 147 m_marginIntervals = m_intervals->computeShapeMarginIntervals(std::min(shapeMarginInt, maxShapeMarginInt)); 148 149 return *m_marginIntervals; 150} 151 152void RasterShape::getExcludedIntervals(LayoutUnit logicalTop, LayoutUnit logicalHeight, SegmentList& result) const 153{ 154 const RasterShapeIntervals& intervals = marginIntervals(); 155 if (intervals.isEmpty()) 156 return; 157 158 int y1 = logicalTop; 159 int y2 = logicalTop + logicalHeight; 160 ASSERT(y2 >= y1); 161 if (y2 < intervals.bounds().y() || y1 >= intervals.bounds().maxY()) 162 return; 163 164 y1 = std::max(y1, intervals.bounds().y()); 165 y2 = std::min(y2, intervals.bounds().maxY()); 166 IntShapeInterval excludedInterval; 167 168 for (int y = y1; y < y2; y++) 169 excludedInterval.unite(intervals.intervalAt(y)); 170 171 result.append(LineSegment(excludedInterval.x1(), excludedInterval.x2())); 172} 173 174} // namespace WebCore 175