1 /* 2 * Copyright (C) 2003, 2006 Apple Computer, Inc. All rights reserved. 3 * 2006 Rob Buis <buis (at) kde.org> 4 * Copyright (C) 2007 Eric Seidel <eric (at) webkit.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 29 #include "config.h" 30 #include "Path.h" 31 32 #include "FloatPoint.h" 33 #include "FloatRect.h" 34 #include "PathTraversalState.h" 35 #include <math.h> 36 #include <wtf/MathExtras.h> 37 38 // Approximation of control point positions on a bezier to simulate a quarter of a circle. 39 static const float gCircleControlPoint = 0.448f; 40 41 namespace WebCore { 42 43 #if !PLATFORM(OPENVG) && !PLATFORM(QT) 44 static void pathLengthApplierFunction(void* info, const PathElement* element) 45 { 46 PathTraversalState& traversalState = *static_cast<PathTraversalState*>(info); 47 if (traversalState.m_success) 48 return; 49 traversalState.m_previous = traversalState.m_current; 50 FloatPoint* points = element->points; 51 float segmentLength = 0; 52 switch (element->type) { 53 case PathElementMoveToPoint: 54 segmentLength = traversalState.moveTo(points[0]); 55 break; 56 case PathElementAddLineToPoint: 57 segmentLength = traversalState.lineTo(points[0]); 58 break; 59 case PathElementAddQuadCurveToPoint: 60 segmentLength = traversalState.quadraticBezierTo(points[0], points[1]); 61 break; 62 case PathElementAddCurveToPoint: 63 segmentLength = traversalState.cubicBezierTo(points[0], points[1], points[2]); 64 break; 65 case PathElementCloseSubpath: 66 segmentLength = traversalState.closeSubpath(); 67 break; 68 } 69 traversalState.m_totalLength += segmentLength; 70 if ((traversalState.m_action == PathTraversalState::TraversalPointAtLength || 71 traversalState.m_action == PathTraversalState::TraversalNormalAngleAtLength) && 72 (traversalState.m_totalLength >= traversalState.m_desiredLength)) { 73 FloatSize change = traversalState.m_current - traversalState.m_previous; 74 float slope = atan2f(change.height(), change.width()); 75 76 if (traversalState.m_action == PathTraversalState::TraversalPointAtLength) { 77 float offset = traversalState.m_desiredLength - traversalState.m_totalLength; 78 traversalState.m_current.move(offset * cosf(slope), offset * sinf(slope)); 79 } else 80 traversalState.m_normalAngle = rad2deg(slope); 81 82 traversalState.m_success = true; 83 } 84 } 85 86 float Path::length() const 87 { 88 PathTraversalState traversalState(PathTraversalState::TraversalTotalLength); 89 apply(&traversalState, pathLengthApplierFunction); 90 return traversalState.m_totalLength; 91 } 92 93 FloatPoint Path::pointAtLength(float length, bool& ok) const 94 { 95 PathTraversalState traversalState(PathTraversalState::TraversalPointAtLength); 96 traversalState.m_desiredLength = length; 97 apply(&traversalState, pathLengthApplierFunction); 98 ok = traversalState.m_success; 99 return traversalState.m_current; 100 } 101 102 float Path::normalAngleAtLength(float length, bool& ok) const 103 { 104 PathTraversalState traversalState(PathTraversalState::TraversalNormalAngleAtLength); 105 traversalState.m_desiredLength = length ? length : std::numeric_limits<float>::epsilon(); 106 apply(&traversalState, pathLengthApplierFunction); 107 ok = traversalState.m_success; 108 return traversalState.m_normalAngle; 109 } 110 #endif 111 112 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& roundingRadii) 113 { 114 if (rect.isEmpty()) 115 return; 116 117 FloatSize radius(roundingRadii); 118 FloatSize halfSize(rect.width() / 2, rect.height() / 2); 119 120 // If rx is greater than half of the width of the rectangle 121 // then set rx to half of the width (required in SVG spec) 122 if (radius.width() > halfSize.width()) 123 radius.setWidth(halfSize.width()); 124 125 // If ry is greater than half of the height of the rectangle 126 // then set ry to half of the height (required in SVG spec) 127 if (radius.height() > halfSize.height()) 128 radius.setHeight(halfSize.height()); 129 130 moveTo(FloatPoint(rect.x() + radius.width(), rect.y())); 131 132 if (radius.width() < halfSize.width()) 133 addLineTo(FloatPoint(rect.x() + rect.width() - roundingRadii.width(), rect.y())); 134 135 addBezierCurveTo(FloatPoint(rect.x() + rect.width() - radius.width() * gCircleControlPoint, rect.y()), FloatPoint(rect.x() + rect.width(), rect.y() + radius.height() * gCircleControlPoint), FloatPoint(rect.x() + rect.width(), rect.y() + radius.height())); 136 137 if (radius.height() < halfSize.height()) 138 addLineTo(FloatPoint(rect.x() + rect.width(), rect.y() + rect.height() - radius.height())); 139 140 addBezierCurveTo(FloatPoint(rect.x() + rect.width(), rect.y() + rect.height() - radius.height() * gCircleControlPoint), FloatPoint(rect.x() + rect.width() - radius.width() * gCircleControlPoint, rect.y() + rect.height()), FloatPoint(rect.x() + rect.width() - radius.width(), rect.y() + rect.height())); 141 142 if (radius.width() < halfSize.width()) 143 addLineTo(FloatPoint(rect.x() + radius.width(), rect.y() + rect.height())); 144 145 addBezierCurveTo(FloatPoint(rect.x() + radius.width() * gCircleControlPoint, rect.y() + rect.height()), FloatPoint(rect.x(), rect.y() + rect.height() - radius.height() * gCircleControlPoint), FloatPoint(rect.x(), rect.y() + rect.height() - radius.height())); 146 147 if (radius.height() < halfSize.height()) 148 addLineTo(FloatPoint(rect.x(), rect.y() + radius.height())); 149 150 addBezierCurveTo(FloatPoint(rect.x(), rect.y() + radius.height() * gCircleControlPoint), FloatPoint(rect.x() + radius.width() * gCircleControlPoint, rect.y()), FloatPoint(rect.x() + radius.width(), rect.y())); 151 152 closeSubpath(); 153 } 154 155 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 156 { 157 if (rect.isEmpty()) 158 return; 159 160 if (rect.width() < topLeftRadius.width() + topRightRadius.width() 161 || rect.width() < bottomLeftRadius.width() + bottomRightRadius.width() 162 || rect.height() < topLeftRadius.height() + bottomLeftRadius.height() 163 || rect.height() < topRightRadius.height() + bottomRightRadius.height()) { 164 // If all the radii cannot be accommodated, return a rect. 165 addRect(rect); 166 return; 167 } 168 169 moveTo(FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 170 171 addLineTo(FloatPoint(rect.x() + rect.width() - topRightRadius.width(), rect.y())); 172 addBezierCurveTo(FloatPoint(rect.x() + rect.width() - topRightRadius.width() * gCircleControlPoint, rect.y()), 173 FloatPoint(rect.x() + rect.width(), rect.y() + topRightRadius.height() * gCircleControlPoint), 174 FloatPoint(rect.x() + rect.width(), rect.y() + topRightRadius.height())); 175 addLineTo(FloatPoint(rect.x() + rect.width(), rect.y() + rect.height() - bottomRightRadius.height())); 176 addBezierCurveTo(FloatPoint(rect.x() + rect.width(), rect.y() + rect.height() - bottomRightRadius.height() * gCircleControlPoint), 177 FloatPoint(rect.x() + rect.width() - bottomRightRadius.width() * gCircleControlPoint, rect.y() + rect.height()), 178 FloatPoint(rect.x() + rect.width() - bottomRightRadius.width(), rect.y() + rect.height())); 179 addLineTo(FloatPoint(rect.x() + bottomLeftRadius.width(), rect.y() + rect.height())); 180 addBezierCurveTo(FloatPoint(rect.x() + bottomLeftRadius.width() * gCircleControlPoint, rect.y() + rect.height()), 181 FloatPoint(rect.x(), rect.y() + rect.height() - bottomLeftRadius.height() * gCircleControlPoint), 182 FloatPoint(rect.x(), rect.y() + rect.height() - bottomLeftRadius.height())); 183 addLineTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height())); 184 addBezierCurveTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height() * gCircleControlPoint), 185 FloatPoint(rect.x() + topLeftRadius.width() * gCircleControlPoint, rect.y()), 186 FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 187 188 closeSubpath(); 189 } 190 191 void Path::addRoundedRect(const RoundedIntRect& r) 192 { 193 addRoundedRect(r.rect(), r.radii().topLeft(), r.radii().topRight(), r.radii().bottomLeft(), r.radii().bottomRight()); 194 } 195 196 } 197
