1 /* 2 * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved. 3 * Copyright (C) 2005 Nokia. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "config.h" 28 #include "FloatPoint.h" 29 30 #include "AffineTransform.h" 31 #include "TransformationMatrix.h" 32 #include "FloatConversion.h" 33 #include "IntPoint.h" 34 #include <limits> 35 #include <math.h> 36 37 namespace WebCore { 38 39 FloatPoint::FloatPoint(const IntPoint& p) : m_x(p.x()), m_y(p.y()) 40 { 41 } 42 43 void FloatPoint::normalize() 44 { 45 float tempLength = length(); 46 47 if (tempLength) { 48 m_x /= tempLength; 49 m_y /= tempLength; 50 } 51 } 52 53 float FloatPoint::length() const 54 { 55 return sqrtf(lengthSquared()); 56 } 57 58 FloatPoint FloatPoint::matrixTransform(const AffineTransform& transform) const 59 { 60 double newX, newY; 61 transform.map(static_cast<double>(m_x), static_cast<double>(m_y), newX, newY); 62 return narrowPrecision(newX, newY); 63 } 64 65 FloatPoint FloatPoint::matrixTransform(const TransformationMatrix& transform) const 66 { 67 double newX, newY; 68 transform.map(static_cast<double>(m_x), static_cast<double>(m_y), newX, newY); 69 return narrowPrecision(newX, newY); 70 } 71 72 FloatPoint FloatPoint::narrowPrecision(double x, double y) 73 { 74 return FloatPoint(narrowPrecisionToFloat(x), narrowPrecisionToFloat(y)); 75 } 76 77 float findSlope(const FloatPoint& p1, const FloatPoint& p2, float& c) 78 { 79 if (p2.x() == p1.x()) 80 return std::numeric_limits<float>::infinity(); 81 82 // y = mx + c 83 float slope = (p2.y() - p1.y()) / (p2.x() - p1.x()); 84 c = p1.y() - slope * p1.x(); 85 return slope; 86 } 87 88 bool findIntersection(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& d1, const FloatPoint& d2, FloatPoint& intersection) 89 { 90 float pOffset = 0; 91 float pSlope = findSlope(p1, p2, pOffset); 92 93 float dOffset = 0; 94 float dSlope = findSlope(d1, d2, dOffset); 95 96 if (dSlope == pSlope) 97 return false; 98 99 if (pSlope == std::numeric_limits<float>::infinity()) { 100 intersection.setX(p1.x()); 101 intersection.setY(dSlope * intersection.x() + dOffset); 102 return true; 103 } 104 if (dSlope == std::numeric_limits<float>::infinity()) { 105 intersection.setX(d1.x()); 106 intersection.setY(pSlope * intersection.x() + pOffset); 107 return true; 108 } 109 110 // Find x at intersection, where ys overlap; x = (c' - c) / (m - m') 111 intersection.setX((dOffset - pOffset) / (pSlope - dSlope)); 112 intersection.setY(pSlope * intersection.x() + pOffset); 113 return true; 114 } 115 116 } 117
