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29 #include "core/rendering/svg/RenderSVGEllipse.h"
31 #include "core/svg/SVGCircleElement.h"
32 #include "core/svg/SVGEllipseElement.h"
36 RenderSVGEllipse::RenderSVGEllipse(SVGGraphicsElement* node)
37 : RenderSVGShape(node)
38 , m_usePathFallback(false)
42 RenderSVGEllipse::~RenderSVGEllipse()
46 void RenderSVGEllipse::updateShapeFromElement()
48 // Before creating a new object we need to clear the cached bounding box
49 // to avoid using garbage.
50 m_fillBoundingBox = FloatRect();
51 m_strokeBoundingBox = FloatRect();
52 m_center = FloatPoint();
53 m_radii = FloatSize();
54 m_usePathFallback = false;
56 calculateRadiiAndCenter();
58 // Spec: "A negative value is an error. A value of zero disables rendering of the element."
59 if (m_radii.width() < 0 || m_radii.height() < 0)
62 if (!m_radii.isEmpty()) {
63 // Fallback to RenderSVGShape if shape has a non-scaling stroke.
64 if (hasNonScalingStroke()) {
65 RenderSVGShape::updateShapeFromElement();
66 m_usePathFallback = true;
71 m_fillBoundingBox = FloatRect(m_center.x() - m_radii.width(), m_center.y() - m_radii.height(), 2 * m_radii.width(), 2 * m_radii.height());
72 m_strokeBoundingBox = m_fillBoundingBox;
73 if (style()->svgStyle().hasStroke())
74 m_strokeBoundingBox.inflate(strokeWidth() / 2);
77 void RenderSVGEllipse::calculateRadiiAndCenter()
80 if (isSVGCircleElement(*element())) {
81 SVGCircleElement& circle = toSVGCircleElement(*element());
83 SVGLengthContext lengthContext(&circle);
84 float radius = circle.r()->currentValue()->value(lengthContext);
85 m_radii = FloatSize(radius, radius);
86 m_center = FloatPoint(circle.cx()->currentValue()->value(lengthContext), circle.cy()->currentValue()->value(lengthContext));
90 SVGEllipseElement& ellipse = toSVGEllipseElement(*element());
92 SVGLengthContext lengthContext(&ellipse);
93 m_radii = FloatSize(ellipse.rx()->currentValue()->value(lengthContext), ellipse.ry()->currentValue()->value(lengthContext));
94 m_center = FloatPoint(ellipse.cx()->currentValue()->value(lengthContext), ellipse.cy()->currentValue()->value(lengthContext));
97 bool RenderSVGEllipse::shapeDependentStrokeContains(const FloatPoint& point)
99 // The optimized contains code below does not support non-smooth strokes so we need
100 // to fall back to RenderSVGShape::shapeDependentStrokeContains in these cases.
101 if (m_usePathFallback || !hasSmoothStroke()) {
103 RenderSVGShape::updateShapeFromElement();
104 return RenderSVGShape::shapeDependentStrokeContains(point);
107 float halfStrokeWidth = strokeWidth() / 2;
108 FloatPoint center = FloatPoint(m_center.x() - point.x(), m_center.y() - point.y());
110 // This works by checking if the point satisfies the ellipse equation,
111 // (x/rX)^2 + (y/rY)^2 <= 1, for the outer but not the inner stroke.
112 float xrXOuter = center.x() / (m_radii.width() + halfStrokeWidth);
113 float yrYOuter = center.y() / (m_radii.height() + halfStrokeWidth);
114 if (xrXOuter * xrXOuter + yrYOuter * yrYOuter > 1.0)
117 float xrXInner = center.x() / (m_radii.width() - halfStrokeWidth);
118 float yrYInner = center.y() / (m_radii.height() - halfStrokeWidth);
119 return xrXInner * xrXInner + yrYInner * yrYInner >= 1.0;
122 bool RenderSVGEllipse::shapeDependentFillContains(const FloatPoint& point, const WindRule fillRule) const
124 if (m_usePathFallback)
125 return RenderSVGShape::shapeDependentFillContains(point, fillRule);
127 FloatPoint center = FloatPoint(m_center.x() - point.x(), m_center.y() - point.y());
129 // This works by checking if the point satisfies the ellipse equation.
130 // (x/rX)^2 + (y/rY)^2 <= 1
131 float xrX = center.x() / m_radii.width();
132 float yrY = center.y() / m_radii.height();
133 return xrX * xrX + yrY * yrY <= 1.0;