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* Copyright (C) 2008 Apple Inc. All rights reserved.
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* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
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* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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#ifndef FloatQuad_h
#define FloatQuad_h
#include "platform/geometry/FloatPoint.h"
#include "platform/geometry/FloatRect.h"
#include "platform/geometry/IntRect.h"
namespace WebCore {
// A FloatQuad is a collection of 4 points, often representing the result of
// mapping a rectangle through transforms. When initialized from a rect, the
// points are in clockwise order from top left.
class PLATFORM_EXPORT FloatQuad {
public:
FloatQuad()
{
}
FloatQuad(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& p3, const FloatPoint& p4)
: m_p1(p1)
, m_p2(p2)
, m_p3(p3)
, m_p4(p4)
{
}
FloatQuad(const FloatRect& inRect)
: m_p1(inRect.location())
, m_p2(inRect.maxX(), inRect.y())
, m_p3(inRect.maxX(), inRect.maxY())
, m_p4(inRect.x(), inRect.maxY())
{
}
FloatPoint p1() const { return m_p1; }
FloatPoint p2() const { return m_p2; }
FloatPoint p3() const { return m_p3; }
FloatPoint p4() const { return m_p4; }
void setP1(const FloatPoint& p) { m_p1 = p; }
void setP2(const FloatPoint& p) { m_p2 = p; }
void setP3(const FloatPoint& p) { m_p3 = p; }
void setP4(const FloatPoint& p) { m_p4 = p; }
// isEmpty tests that the bounding box is empty. This will not identify
// "slanted" empty quads.
bool isEmpty() const { return boundingBox().isEmpty(); }
// Tests whether this quad can be losslessly represented by a FloatRect,
// that is, if two edges are parallel to the x-axis and the other two
// are parallel to the y-axis. If this method returns true, the
// corresponding FloatRect can be retrieved with boundingBox().
bool isRectilinear() const;
// Tests whether the given point is inside, or on an edge or corner of this quad.
bool containsPoint(const FloatPoint&) const;
// Tests whether the four corners of other are inside, or coincident with the sides of this quad.
// Note that this only works for convex quads, but that includes all quads that originate
// from transformed rects.
bool containsQuad(const FloatQuad&) const;
// Tests whether any part of the rectangle intersects with this quad.
// This only works for convex quads.
bool intersectsRect(const FloatRect&) const;
// Test whether any part of the circle/ellipse intersects with this quad.
// Note that these two functions only work for convex quads.
bool intersectsCircle(const FloatPoint& center, float radius) const;
bool intersectsEllipse(const FloatPoint& center, const FloatSize& radii) const;
// 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.
FloatPoint center() const
{
return FloatPoint((m_p1.x() + m_p2.x() + m_p3.x() + m_p4.x()) / 4.0,
(m_p1.y() + m_p2.y() + m_p3.y() + m_p4.y()) / 4.0);
}
FloatRect boundingBox() const;
IntRect enclosingBoundingBox() const
{
return enclosingIntRect(boundingBox());
}
void move(const FloatSize& offset)
{
m_p1 += offset;
m_p2 += offset;
m_p3 += offset;
m_p4 += offset;
}
void move(float dx, float dy)
{
m_p1.move(dx, dy);
m_p2.move(dx, dy);
m_p3.move(dx, dy);
m_p4.move(dx, dy);
}
void scale(float dx, float dy)
{
m_p1.scale(dx, dy);
m_p2.scale(dx, dy);
m_p3.scale(dx, dy);
m_p4.scale(dx, dy);
}
// Tests whether points are in clock-wise, or counter clock-wise order.
// Note that output is undefined when all points are colinear.
bool isCounterclockwise() const;
private:
FloatPoint m_p1;
FloatPoint m_p2;
FloatPoint m_p3;
FloatPoint m_p4;
};
inline FloatQuad& operator+=(FloatQuad& a, const FloatSize& b)
{
a.move(b);
return a;
}
inline FloatQuad& operator-=(FloatQuad& a, const FloatSize& b)
{
a.move(-b.width(), -b.height());
return a;
}
inline bool operator==(const FloatQuad& a, const FloatQuad& b)
{
return a.p1() == b.p1() &&
a.p2() == b.p2() &&
a.p3() == b.p3() &&
a.p4() == b.p4();
}
inline bool operator!=(const FloatQuad& a, const FloatQuad& b)
{
return a.p1() != b.p1() ||
a.p2() != b.p2() ||
a.p3() != b.p3() ||
a.p4() != b.p4();
}
} // namespace WebCore
#endif // FloatQuad_h