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 "platform/geometry/FloatPoint.h" 29 30 #include "SkPoint.h" 31 #include "platform/FloatConversion.h" 32 #include "platform/geometry/LayoutPoint.h" 33 #include "platform/geometry/LayoutSize.h" 34 #include <limits> 35 #include <math.h> 36 37 namespace blink { 38 39 // Skia has problems when passed infinite, etc floats, filter them to 0. 40 static inline SkScalar WebCoreFloatToSkScalar(float f) 41 { 42 return SkFloatToScalar(std::isfinite(f) ? f : 0); 43 } 44 45 FloatPoint::FloatPoint(const IntPoint& p) : m_x(p.x()), m_y(p.y()) 46 { 47 } 48 49 FloatPoint::FloatPoint(const LayoutPoint& p) 50 : m_x(p.x().toFloat()) 51 , m_y(p.y().toFloat()) 52 { 53 } 54 55 void FloatPoint::normalize() 56 { 57 float tempLength = length(); 58 59 if (tempLength) { 60 m_x /= tempLength; 61 m_y /= tempLength; 62 } 63 } 64 65 float FloatPoint::slopeAngleRadians() const 66 { 67 return atan2f(m_y, m_x); 68 } 69 70 float FloatPoint::length() const 71 { 72 return sqrtf(lengthSquared()); 73 } 74 75 void FloatPoint::move(const LayoutSize& size) 76 { 77 m_x += size.width(); 78 m_y += size.height(); 79 } 80 81 void FloatPoint::moveBy(const LayoutPoint& point) 82 { 83 m_x += point.x(); 84 m_y += point.y(); 85 } 86 87 SkPoint FloatPoint::data() const 88 { 89 SkPoint p = { WebCoreFloatToSkScalar(m_x), WebCoreFloatToSkScalar(m_y) }; 90 return p; 91 } 92 93 FloatPoint FloatPoint::narrowPrecision(double x, double y) 94 { 95 return FloatPoint(narrowPrecisionToFloat(x), narrowPrecisionToFloat(y)); 96 } 97 98 float findSlope(const FloatPoint& p1, const FloatPoint& p2, float& c) 99 { 100 if (p2.x() == p1.x()) 101 return std::numeric_limits<float>::infinity(); 102 103 // y = mx + c 104 float slope = (p2.y() - p1.y()) / (p2.x() - p1.x()); 105 c = p1.y() - slope * p1.x(); 106 return slope; 107 } 108 109 bool findIntersection(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& d1, const FloatPoint& d2, FloatPoint& intersection) 110 { 111 float pxLength = p2.x() - p1.x(); 112 float pyLength = p2.y() - p1.y(); 113 114 float dxLength = d2.x() - d1.x(); 115 float dyLength = d2.y() - d1.y(); 116 117 float denom = pxLength * dyLength - pyLength * dxLength; 118 if (!denom) 119 return false; 120 121 float param = ((d1.x() - p1.x()) * dyLength - (d1.y() - p1.y()) * dxLength) / denom; 122 123 intersection.setX(p1.x() + param * pxLength); 124 intersection.setY(p1.y() + param * pyLength); 125 return true; 126 } 127 128 } 129