1 /* 2 * Copyright (C) 2008 Apple Inc. 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 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 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef FloatQuad_h 30 #define FloatQuad_h 31 32 #include "platform/geometry/FloatPoint.h" 33 #include "platform/geometry/FloatRect.h" 34 #include "platform/geometry/IntRect.h" 35 36 namespace WebCore { 37 38 // A FloatQuad is a collection of 4 points, often representing the result of 39 // mapping a rectangle through transforms. When initialized from a rect, the 40 // points are in clockwise order from top left. 41 class PLATFORM_EXPORT FloatQuad { 42 public: FloatQuad()43 FloatQuad() 44 { 45 } 46 FloatQuad(const FloatPoint & p1,const FloatPoint & p2,const FloatPoint & p3,const FloatPoint & p4)47 FloatQuad(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& p3, const FloatPoint& p4) 48 : m_p1(p1) 49 , m_p2(p2) 50 , m_p3(p3) 51 , m_p4(p4) 52 { 53 } 54 FloatQuad(const FloatRect & inRect)55 FloatQuad(const FloatRect& inRect) 56 : m_p1(inRect.location()) 57 , m_p2(inRect.maxX(), inRect.y()) 58 , m_p3(inRect.maxX(), inRect.maxY()) 59 , m_p4(inRect.x(), inRect.maxY()) 60 { 61 } 62 p1()63 FloatPoint p1() const { return m_p1; } p2()64 FloatPoint p2() const { return m_p2; } p3()65 FloatPoint p3() const { return m_p3; } p4()66 FloatPoint p4() const { return m_p4; } 67 setP1(const FloatPoint & p)68 void setP1(const FloatPoint& p) { m_p1 = p; } setP2(const FloatPoint & p)69 void setP2(const FloatPoint& p) { m_p2 = p; } setP3(const FloatPoint & p)70 void setP3(const FloatPoint& p) { m_p3 = p; } setP4(const FloatPoint & p)71 void setP4(const FloatPoint& p) { m_p4 = p; } 72 73 // isEmpty tests that the bounding box is empty. This will not identify 74 // "slanted" empty quads. isEmpty()75 bool isEmpty() const { return boundingBox().isEmpty(); } 76 77 // Tests whether this quad can be losslessly represented by a FloatRect, 78 // that is, if two edges are parallel to the x-axis and the other two 79 // are parallel to the y-axis. If this method returns true, the 80 // corresponding FloatRect can be retrieved with boundingBox(). 81 bool isRectilinear() const; 82 83 // Tests whether the given point is inside, or on an edge or corner of this quad. 84 bool containsPoint(const FloatPoint&) const; 85 86 // Tests whether the four corners of other are inside, or coincident with the sides of this quad. 87 // Note that this only works for convex quads, but that includes all quads that originate 88 // from transformed rects. 89 bool containsQuad(const FloatQuad&) const; 90 91 // Tests whether any part of the rectangle intersects with this quad. 92 // This only works for convex quads. 93 bool intersectsRect(const FloatRect&) const; 94 95 // Test whether any part of the circle/ellipse intersects with this quad. 96 // Note that these two functions only work for convex quads. 97 bool intersectsCircle(const FloatPoint& center, float radius) const; 98 bool intersectsEllipse(const FloatPoint& center, const FloatSize& radii) const; 99 100 // The center of the quad. If the quad is the result of a affine-transformed rectangle this is the same as the original center transformed. center()101 FloatPoint center() const 102 { 103 return FloatPoint((m_p1.x() + m_p2.x() + m_p3.x() + m_p4.x()) / 4.0, 104 (m_p1.y() + m_p2.y() + m_p3.y() + m_p4.y()) / 4.0); 105 } 106 107 FloatRect boundingBox() const; enclosingBoundingBox()108 IntRect enclosingBoundingBox() const 109 { 110 return enclosingIntRect(boundingBox()); 111 } 112 move(const FloatSize & offset)113 void move(const FloatSize& offset) 114 { 115 m_p1 += offset; 116 m_p2 += offset; 117 m_p3 += offset; 118 m_p4 += offset; 119 } 120 move(float dx,float dy)121 void move(float dx, float dy) 122 { 123 m_p1.move(dx, dy); 124 m_p2.move(dx, dy); 125 m_p3.move(dx, dy); 126 m_p4.move(dx, dy); 127 } 128 scale(float dx,float dy)129 void scale(float dx, float dy) 130 { 131 m_p1.scale(dx, dy); 132 m_p2.scale(dx, dy); 133 m_p3.scale(dx, dy); 134 m_p4.scale(dx, dy); 135 } 136 137 // Tests whether points are in clock-wise, or counter clock-wise order. 138 // Note that output is undefined when all points are colinear. 139 bool isCounterclockwise() const; 140 141 private: 142 FloatPoint m_p1; 143 FloatPoint m_p2; 144 FloatPoint m_p3; 145 FloatPoint m_p4; 146 }; 147 148 inline FloatQuad& operator+=(FloatQuad& a, const FloatSize& b) 149 { 150 a.move(b); 151 return a; 152 } 153 154 inline FloatQuad& operator-=(FloatQuad& a, const FloatSize& b) 155 { 156 a.move(-b.width(), -b.height()); 157 return a; 158 } 159 160 inline bool operator==(const FloatQuad& a, const FloatQuad& b) 161 { 162 return a.p1() == b.p1() && 163 a.p2() == b.p2() && 164 a.p3() == b.p3() && 165 a.p4() == b.p4(); 166 } 167 168 inline bool operator!=(const FloatQuad& a, const FloatQuad& b) 169 { 170 return a.p1() != b.p1() || 171 a.p2() != b.p2() || 172 a.p3() != b.p3() || 173 a.p4() != b.p4(); 174 } 175 176 } // namespace WebCore 177 178 179 #endif // FloatQuad_h 180 181