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/*
* Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Region_h
#define Region_h
#include "IntRect.h"
#include <wtf/Vector.h>
namespace WebCore {
class Region {
public:
Region();
Region(const IntRect&);
IntRect bounds() const { return m_bounds; }
bool isEmpty() const { return m_bounds.isEmpty(); }
bool isRect() const { return m_shape.isRect(); }
Vector<IntRect> rects() const;
void unite(const Region&);
void intersect(const Region&);
void subtract(const Region&);
void translate(const IntSize&);
// Returns true if the query region is a subset of this region.
bool contains(const Region&) const;
bool contains(const IntPoint&) const;
// Returns true if the query region intersects any part of this region.
bool intersects(const Region&) const;
unsigned totalArea() const;
#ifndef NDEBUG
void dump() const;
#endif
private:
struct Span {
Span(int y, size_t segmentIndex)
: y(y), segmentIndex(segmentIndex)
{
}
int y;
size_t segmentIndex;
};
class Shape {
public:
Shape();
Shape(const IntRect&);
IntRect bounds() const;
bool isEmpty() const { return m_spans.isEmpty(); }
bool isRect() const { return m_spans.size() <= 2 && m_segments.size() <= 2; }
typedef const Span* SpanIterator;
SpanIterator spans_begin() const;
SpanIterator spans_end() const;
typedef const int* SegmentIterator;
SegmentIterator segments_begin(SpanIterator) const;
SegmentIterator segments_end(SpanIterator) const;
static Shape unionShapes(const Shape& shape1, const Shape& shape2);
static Shape intersectShapes(const Shape& shape1, const Shape& shape2);
static Shape subtractShapes(const Shape& shape1, const Shape& shape2);
void translate(const IntSize&);
void swap(Shape&);
struct CompareContainsOperation;
struct CompareIntersectsOperation;
template<typename CompareOperation>
static bool compareShapes(const Shape& shape1, const Shape& shape2);
#ifndef NDEBUG
void dump() const;
#endif
private:
struct UnionOperation;
struct IntersectOperation;
struct SubtractOperation;
template<typename Operation>
static Shape shapeOperation(const Shape& shape1, const Shape& shape2);
void appendSegment(int x);
void appendSpan(int y);
void appendSpan(int y, SegmentIterator begin, SegmentIterator end);
void appendSpans(const Shape&, SpanIterator begin, SpanIterator end);
bool canCoalesce(SegmentIterator begin, SegmentIterator end);
Vector<int, 32> m_segments;
Vector<Span, 16> m_spans;
friend bool operator==(const Shape&, const Shape&);
};
IntRect m_bounds;
Shape m_shape;
friend bool operator==(const Region&, const Region&);
friend bool operator==(const Shape&, const Shape&);
friend bool operator==(const Span&, const Span&);
};
static inline Region intersect(const Region& a, const Region& b)
{
Region result(a);
result.intersect(b);
return result;
}
static inline Region subtract(const Region& a, const Region& b)
{
Region result(a);
result.subtract(b);
return result;
}
static inline Region translate(const Region& region, const IntSize& offset)
{
Region result(region);
result.translate(offset);
return result;
}
inline bool operator==(const Region& a, const Region& b)
{
return a.m_bounds == b.m_bounds && a.m_shape == b.m_shape;
}
inline bool operator==(const Region::Shape& a, const Region::Shape& b)
{
return a.m_spans == b.m_spans && a.m_segments == b.m_segments;
}
inline bool operator==(const Region::Span& a, const Region::Span& b)
{
return a.y == b.y && a.segmentIndex == b.segmentIndex;
}
} // namespace WebCore
#endif // Region_h
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