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.
WebCoreFloatToSkScalar(float f)40 static inline SkScalar WebCoreFloatToSkScalar(float f)
41 {
42 return SkFloatToScalar(std::isfinite(f) ? f : 0);
43 }
44
FloatPoint(const IntPoint & p)45 FloatPoint::FloatPoint(const IntPoint& p) : m_x(p.x()), m_y(p.y())
46 {
47 }
48
FloatPoint(const LayoutPoint & p)49 FloatPoint::FloatPoint(const LayoutPoint& p)
50 : m_x(p.x().toFloat())
51 , m_y(p.y().toFloat())
52 {
53 }
54
normalize()55 void FloatPoint::normalize()
56 {
57 float tempLength = length();
58
59 if (tempLength) {
60 m_x /= tempLength;
61 m_y /= tempLength;
62 }
63 }
64
slopeAngleRadians() const65 float FloatPoint::slopeAngleRadians() const
66 {
67 return atan2f(m_y, m_x);
68 }
69
length() const70 float FloatPoint::length() const
71 {
72 return sqrtf(lengthSquared());
73 }
74
move(const LayoutSize & size)75 void FloatPoint::move(const LayoutSize& size)
76 {
77 m_x += size.width();
78 m_y += size.height();
79 }
80
moveBy(const LayoutPoint & point)81 void FloatPoint::moveBy(const LayoutPoint& point)
82 {
83 m_x += point.x();
84 m_y += point.y();
85 }
86
data() const87 SkPoint FloatPoint::data() const
88 {
89 SkPoint p = { WebCoreFloatToSkScalar(m_x), WebCoreFloatToSkScalar(m_y) };
90 return p;
91 }
92
narrowPrecision(double x,double y)93 FloatPoint FloatPoint::narrowPrecision(double x, double y)
94 {
95 return FloatPoint(narrowPrecisionToFloat(x), narrowPrecisionToFloat(y));
96 }
97
findSlope(const FloatPoint & p1,const FloatPoint & p2,float & c)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
findIntersection(const FloatPoint & p1,const FloatPoint & p2,const FloatPoint & d1,const FloatPoint & d2,FloatPoint & intersection)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