DYT/Tool/OpenSceneGraph-3.6.5/include/geos/operation/relateng/PolygonNodeConverter.h

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2024-12-24 23:49:36 +00:00
/**********************************************************************
*
* GEOS - Geometry Engine Open Source
* http://geos.osgeo.org
*
* Copyright (c) 2024 Martin Davis
* Copyright (C) 2024 Paul Ramsey <pramsey@cleverelephant.ca>
*
* This is free software; you can redistribute and/or modify it under
* the terms of the GNU Lesser General Public Licence as published
* by the Free Software Foundation.
* See the COPYING file for more information.
*
**********************************************************************/
#pragma once
#include <geos/operation/relateng/NodeSection.h>
#include <geos/export.h>
#include <vector>
#include <memory>
// Forward declarations
namespace geos {
namespace operation {
namespace relateng {
// class NodeSection;
}
}
}
// using geos::geom::CoordinateXY;
// using geos::geom::Geometry;
namespace geos { // geos.
namespace operation { // geos.operation
namespace relateng { // geos.operation.relateng
/**
* Converts the node sections at a polygon node where
* a shell and one or more holes touch, or two or more holes touch.
* This converts the node topological structure from
* the OGC "touching-rings" (AKA "minimal-ring") model to the equivalent "self-touch"
* (AKA "inverted/exverted ring" or "maximal ring") model.
* In the "self-touch" model the converted NodeSection corners enclose areas
* which all lies inside the polygon
* (i.e. they does not enclose hole edges).
* This allows RelateNode to use simple area-additive semantics
* for adding edges and propagating edge locations.
*
* The input node sections are assumed to have canonical orientation
* (CW shells and CCW holes).
* The arrangement of shells and holes must be topologically valid.
* Specifically, the node sections must not cross or be collinear.
*
* This supports multiple shell-shell touches
* (including ones containing holes), and hole-hole touches,
* This generalizes the relate algorithm to support
* both the OGC model and the self-touch model.
*
* @author Martin Davis
* @see RelateNode
*/
class GEOS_DLL PolygonNodeConverter {
public:
/**
* Converts a list of sections of valid polygon rings
* to have "self-touching" structure.
* There are the same number of output sections as input ones.
*
* @param polySections the original sections
* @return the converted sections
*/
static std::vector<std::unique_ptr<NodeSection>> convert(
std::vector<const NodeSection*>& polySections);
private:
static std::size_t convertShellAndHoles(
std::vector<const NodeSection*>& sections,
std::size_t shellIndex,
std::vector<std::unique_ptr<NodeSection>>& convertedSections);
static std::vector<std::unique_ptr<NodeSection>> convertHoles(
std::vector<const NodeSection*>& sections);
static NodeSection* createSection(
const NodeSection* ns,
const CoordinateXY* v0,
const CoordinateXY* v1);
static std::vector<const NodeSection*> extractUnique(
std::vector<const NodeSection*>& sections);
static std::size_t next(
std::vector<const NodeSection *>& ns, std::size_t i);
static std::size_t findShell(
std::vector<const NodeSection *>& polySections);
};
} // namespace geos.operation.relateng
} // namespace geos.operation
} // namespace geos