1/*
2 * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
3 * Copyright (C) 2004, 2005, 2008 Rob Buis <buis@kde.org>
4 * Copyright (C) 2005, 2007 Eric Seidel <eric@webkit.org>
5 * Copyright (C) 2009 Google, Inc.
6 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
7 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
8 * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
9 * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
10 * Copyright (C) 2011 University of Szeged
11 *
12 * This library is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU Library General Public
14 * License as published by the Free Software Foundation; either
15 * version 2 of the License, or (at your option) any later version.
16 *
17 * This library is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20 * Library General Public License for more details.
21 *
22 * You should have received a copy of the GNU Library General Public License
23 * along with this library; see the file COPYING.LIB.  If not, write to
24 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
25 * Boston, MA 02110-1301, USA.
26 */
27
28#include "config.h"
29
30#include "core/rendering/svg/RenderSVGPath.h"
31
32#include "core/rendering/svg/SVGSubpathData.h"
33#include "platform/graphics/GraphicsContextStateSaver.h"
34
35namespace WebCore {
36
37RenderSVGPath::RenderSVGPath(SVGGraphicsElement* node)
38    : RenderSVGShape(node)
39{
40}
41
42RenderSVGPath::~RenderSVGPath()
43{
44}
45
46void RenderSVGPath::updateShapeFromElement()
47{
48    RenderSVGShape::updateShapeFromElement();
49    updateZeroLengthSubpaths();
50
51    m_strokeBoundingBox = calculateUpdatedStrokeBoundingBox();
52}
53
54FloatRect RenderSVGPath::calculateUpdatedStrokeBoundingBox() const
55{
56    FloatRect strokeBoundingBox = m_strokeBoundingBox;
57
58    if (style()->svgStyle()->hasStroke()) {
59        // FIXME: zero-length subpaths do not respect vector-effect = non-scaling-stroke.
60        float strokeWidth = this->strokeWidth();
61        for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i)
62            strokeBoundingBox.unite(zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth));
63    }
64
65    return strokeBoundingBox;
66}
67
68static void useStrokeStyleToFill(GraphicsContext* context)
69{
70    if (Gradient* gradient = context->strokeGradient())
71        context->setFillGradient(gradient);
72    else if (Pattern* pattern = context->strokePattern())
73        context->setFillPattern(pattern);
74    else
75        context->setFillColor(context->strokeColor());
76}
77
78void RenderSVGPath::strokeShape(GraphicsContext* context) const
79{
80    if (!style()->svgStyle()->hasVisibleStroke())
81        return;
82
83    RenderSVGShape::strokeShape(context);
84
85    if (m_zeroLengthLinecapLocations.isEmpty())
86        return;
87
88    Path* usePath;
89    AffineTransform nonScalingTransform;
90
91    if (hasNonScalingStroke())
92        nonScalingTransform = nonScalingStrokeTransform();
93
94    GraphicsContextStateSaver stateSaver(*context, true);
95    useStrokeStyleToFill(context);
96    for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i) {
97        usePath = zeroLengthLinecapPath(m_zeroLengthLinecapLocations[i]);
98        if (hasNonScalingStroke())
99            usePath = nonScalingStrokePath(usePath, nonScalingTransform);
100        context->fillPath(*usePath);
101    }
102}
103
104bool RenderSVGPath::shapeDependentStrokeContains(const FloatPoint& point)
105{
106    if (RenderSVGShape::shapeDependentStrokeContains(point))
107        return true;
108
109    const SVGRenderStyle* svgStyle = style()->svgStyle();
110    for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i) {
111        ASSERT(svgStyle->hasStroke());
112        float strokeWidth = this->strokeWidth();
113        if (svgStyle->capStyle() == SquareCap) {
114            if (zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth).contains(point))
115                return true;
116        } else {
117            ASSERT(svgStyle->capStyle() == RoundCap);
118            FloatPoint radiusVector(point.x() - m_zeroLengthLinecapLocations[i].x(), point.y() -  m_zeroLengthLinecapLocations[i].y());
119            if (radiusVector.lengthSquared() < strokeWidth * strokeWidth * .25f)
120                return true;
121        }
122    }
123    return false;
124}
125
126bool RenderSVGPath::shouldStrokeZeroLengthSubpath() const
127{
128    // Spec(11.4): Any zero length subpath shall not be stroked if the "stroke-linecap" property has a value of butt
129    // but shall be stroked if the "stroke-linecap" property has a value of round or square
130    return style()->svgStyle()->hasStroke() && style()->svgStyle()->capStyle() != ButtCap;
131}
132
133Path* RenderSVGPath::zeroLengthLinecapPath(const FloatPoint& linecapPosition) const
134{
135    DEFINE_STATIC_LOCAL(Path, tempPath, ());
136
137    tempPath.clear();
138    if (style()->svgStyle()->capStyle() == SquareCap)
139        tempPath.addRect(zeroLengthSubpathRect(linecapPosition, this->strokeWidth()));
140    else
141        tempPath.addEllipse(zeroLengthSubpathRect(linecapPosition, this->strokeWidth()));
142
143    return &tempPath;
144}
145
146FloatRect RenderSVGPath::zeroLengthSubpathRect(const FloatPoint& linecapPosition, float strokeWidth) const
147{
148    return FloatRect(linecapPosition.x() - strokeWidth / 2, linecapPosition.y() - strokeWidth / 2, strokeWidth, strokeWidth);
149}
150
151void RenderSVGPath::updateZeroLengthSubpaths()
152{
153    m_zeroLengthLinecapLocations.clear();
154
155    if (!strokeWidth() || !shouldStrokeZeroLengthSubpath())
156        return;
157
158    SVGSubpathData subpathData(m_zeroLengthLinecapLocations);
159    path().apply(&subpathData, SVGSubpathData::updateFromPathElement);
160    subpathData.pathIsDone();
161}
162
163}
164