1 /*
2 * Copyright (C) 2003, 2006 Apple Computer, Inc. All rights reserved.
3 * 2006 Rob Buis <buis@kde.org>
4 * Copyright (C) 2007 Eric Seidel <eric@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)
pathLengthApplierFunction(void * info,const PathElement * element)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
length() const86 float Path::length() const
87 {
88 PathTraversalState traversalState(PathTraversalState::TraversalTotalLength);
89 apply(&traversalState, pathLengthApplierFunction);
90 return traversalState.m_totalLength;
91 }
92
pointAtLength(float length,bool & ok) const93 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
normalAngleAtLength(float length,bool & ok) const102 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
addRoundedRect(const FloatRect & rect,const FloatSize & roundingRadii)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
addRoundedRect(const FloatRect & rect,const FloatSize & topLeftRadius,const FloatSize & topRightRadius,const FloatSize & bottomLeftRadius,const FloatSize & bottomRightRadius)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
addRoundedRect(const RoundedIntRect & r)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