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/*
* Copyright (C) 2012 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDERS AND 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 THE
* COPYRIGHT HOLDER OR 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_FLOAT_POLYGON_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_FLOAT_POLYGON_H_
#include "base/macros.h"
#include "third_party/blink/renderer/platform/geometry/float_point.h"
#include "third_party/blink/renderer/platform/geometry/float_rect.h"
#include "third_party/blink/renderer/platform/wtf/allocator.h"
#include "third_party/blink/renderer/platform/wtf/pod_interval_tree.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"
namespace blink {
class FloatPolygonEdge;
class PLATFORM_EXPORT FloatPolygon {
USING_FAST_MALLOC(FloatPolygon);
public:
explicit FloatPolygon(Vector<FloatPoint> vertices);
const FloatPoint& VertexAt(unsigned index) const { return vertices_[index]; }
unsigned NumberOfVertices() const { return vertices_.size(); }
const FloatPolygonEdge& EdgeAt(unsigned index) const { return edges_[index]; }
unsigned NumberOfEdges() const { return edges_.size(); }
FloatRect BoundingBox() const { return bounding_box_; }
bool OverlappingEdges(float min_y,
float max_y,
Vector<const FloatPolygonEdge*>& result) const;
bool ContainsNonZero(const FloatPoint&) const;
bool ContainsEvenOdd(const FloatPoint&) const;
bool IsEmpty() const { return empty_; }
private:
typedef WTF::PODInterval<float, FloatPolygonEdge*> EdgeInterval;
typedef WTF::PODIntervalTree<float, FloatPolygonEdge*> EdgeIntervalTree;
Vector<FloatPoint> vertices_;
FloatRect bounding_box_;
bool empty_;
Vector<FloatPolygonEdge> edges_;
EdgeIntervalTree edge_tree_; // Each EdgeIntervalTree node stores minY, maxY,
// and a ("UserData") pointer to a
// FloatPolygonEdge.
DISALLOW_COPY_AND_ASSIGN(FloatPolygon);
};
class PLATFORM_EXPORT VertexPair {
public:
virtual ~VertexPair() = default;
virtual const FloatPoint& Vertex1() const = 0;
virtual const FloatPoint& Vertex2() const = 0;
float MinX() const { return std::min(Vertex1().X(), Vertex2().X()); }
float MinY() const { return std::min(Vertex1().Y(), Vertex2().Y()); }
float MaxX() const { return std::max(Vertex1().X(), Vertex2().X()); }
float MaxY() const { return std::max(Vertex1().Y(), Vertex2().Y()); }
bool Intersection(const VertexPair&, FloatPoint&) const;
};
class PLATFORM_EXPORT FloatPolygonEdge final : public VertexPair {
DISALLOW_NEW();
friend class FloatPolygon;
public:
const FloatPoint& Vertex1() const override {
DCHECK(polygon_);
return polygon_->VertexAt(vertex_index1_);
}
const FloatPoint& Vertex2() const override {
DCHECK(polygon_);
return polygon_->VertexAt(vertex_index2_);
}
const FloatPolygonEdge& PreviousEdge() const {
DCHECK(polygon_);
DCHECK_GT(polygon_->NumberOfEdges(), 1UL);
return polygon_->EdgeAt((edge_index_ + polygon_->NumberOfEdges() - 1) %
polygon_->NumberOfEdges());
}
const FloatPolygonEdge& NextEdge() const {
DCHECK(polygon_);
DCHECK_GT(polygon_->NumberOfEdges(), 1UL);
return polygon_->EdgeAt((edge_index_ + 1) % polygon_->NumberOfEdges());
}
const FloatPolygon* Polygon() const { return polygon_; }
unsigned VertexIndex1() const { return vertex_index1_; }
unsigned VertexIndex2() const { return vertex_index2_; }
unsigned EdgeIndex() const { return edge_index_; }
private:
// Edge vertex index1 is less than index2, except the last edge, where index2
// is 0. When a polygon edge is defined by 3 or more colinear vertices, index2
// can be the the index of the last colinear vertex.
unsigned vertex_index1_;
unsigned vertex_index2_;
unsigned edge_index_;
const FloatPolygon* polygon_;
};
} // namespace blink
namespace WTF {
// These structures are used by PODIntervalTree for debugging.
#ifndef NDEBUG
template <>
struct ValueToString<blink::FloatPolygonEdge*> {
STATIC_ONLY(ValueToString);
static String ToString(const blink::FloatPolygonEdge* edge) {
return String::Format("%p (%f,%f %f,%f)", edge, edge->Vertex1().X(),
edge->Vertex1().Y(), edge->Vertex2().X(),
edge->Vertex2().Y());
}
};
#endif
} // namespace WTF
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_FLOAT_POLYGON_H_