/****************************************************************************** * $Id: ogrcurve.cpp 28004 2014-11-26 09:58:44Z rouault $ * * Project: OpenGIS Simple Features Reference Implementation * Purpose: The OGRCurve geometry class. * Author: Frank Warmerdam, warmerda@home.com * ****************************************************************************** * Copyright (c) 1999, Frank Warmerdam * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. ****************************************************************************/ #include "ogr_geometry.h" #include "ogr_p.h" CPL_CVSID("$Id: ogrcurve.cpp 28004 2014-11-26 09:58:44Z rouault $"); /************************************************************************/ /* OGRCurve() */ /************************************************************************/ OGRCurve::OGRCurve() { } /************************************************************************/ /* ~OGRCurve() */ /************************************************************************/ OGRCurve::~OGRCurve() { } /************************************************************************/ /* getDimension() */ /************************************************************************/ int OGRCurve::getDimension() const { return 1; } /************************************************************************/ /* get_IsClosed() */ /************************************************************************/ /** * \brief Return TRUE if curve is closed. * * Tests if a curve is closed. A curve is closed if its start point is * equal to its end point. * * This method relates to the SFCOM ICurve::get_IsClosed() method. * * @return TRUE if closed, else FALSE. */ int OGRCurve::get_IsClosed() const { OGRPoint oStartPoint, oEndPoint; StartPoint( &oStartPoint ); EndPoint( &oEndPoint ); if( oStartPoint.getX() == oEndPoint.getX() && oStartPoint.getY() == oEndPoint.getY() ) { return TRUE; } else { return FALSE; } } /** * \fn double OGRCurve::get_Length() const; * * \brief Returns the length of the curve. * * This method relates to the SFCOM ICurve::get_Length() method. * * @return the length of the curve, zero if the curve hasn't been * initialized. */ /** * \fn void OGRCurve::StartPoint( OGRPoint * poPoint ) const; * * \brief Return the curve start point. * * This method relates to the SF COM ICurve::get_StartPoint() method. * * @param poPoint the point to be assigned the start location. */ /** * \fn void OGRCurve::EndPoint( OGRPoint * poPoint ) const; * * \brief Return the curve end point. * * This method relates to the SF COM ICurve::get_EndPoint() method. * * @param poPoint the point to be assigned the end location. */ /** * \fn void OGRCurve::Value( double dfDistance, OGRPoint * poPoint ) const; * * \brief Fetch point at given distance along curve. * * This method relates to the SF COM ICurve::get_Value() method. * * This function is the same as the C function OGR_G_Value(). * * @param dfDistance distance along the curve at which to sample position. * This distance should be between zero and get_Length() * for this curve. * @param poPoint the point to be assigned the curve position. */ /** * \fn OGRLineString* OGRCurve::CurveToLine( double dfMaxAngleStepSizeDegrees, const char* const* papszOptions ) const; * * \brief Return a linestring from a curve geometry. * * The returned geometry is a new instance whose ownership belongs to the caller. * * If the dfMaxAngleStepSizeDegrees is zero, then a default value will be * used. This is currently 4 degrees unless the user has overridden the * value with the OGR_ARC_STEPSIZE configuration variable. * * This method relates to the ISO SQL/MM Part 3 ICurve::CurveToLine() method. * * This function is the same as C function OGR_G_CurveToLine(). * * @param dfMaxAngleStepSizeDegrees the largest step in degrees along the * arc, zero to use the default setting. * @param papszOptions options as a null-terminated list of strings or NULL. * See OGRGeometryFactory::curveToLineString() for valid options. * * @return a line string approximating the curve * * @since GDAL 2.0 */ /** * \fn int OGRCurve::getNumPoints() const; * * \brief Return the number of points of a curve geometry. * * * This method, as a method of OGRCurve, does not relate to a standard. * For circular strings or linestrings, it returns the number of points, * conforming to SF COM NumPoints(). * For compound curves, it returns the sum of the number of points of each * of its components (non including intermediate starting/ending points of * the different parts). * * @return the number of points of the curve. * * @since GDAL 2.0 */ /** * \fn OGRPointIterator* OGRCurve::getPointIterator() const; * * \brief Returns a point iterator over the curve. * * The curve must not be modified while an iterator exists on it. * * The iterator must be destroyed with OGRPointIterator::destroy(). * * @return a point iterator over the curve. * * @since GDAL 2.0 */ /** * \fn double OGRCurve::get_Area() const; * * \brief Get the area of the (closed) curve. * * This method is designed to be used by OGRCurvePolygon::get_Area(). * * @return the area of the feature in square units of the spatial reference * system in use. * * @since GDAL 2.0 */ /** * \fn double OGRCurve::get_AreaOfCurveSegments() const; * * \brief Get the area of the purely curve portions of a (closed) curve. * * This method is designed to be used on a closed convex curve. * * @return the area of the feature in square units of the spatial reference * system in use. * * @since GDAL 2.0 */ /************************************************************************/ /* IsConvex() */ /************************************************************************/ /** * \brief Returns if a (closed) curve forms a convex shape. * * @return TRUE if the curve forms a convex shape. * * @since GDAL 2.0 */ OGRBoolean OGRCurve::IsConvex() const { OGRBoolean bRet = TRUE; OGRPointIterator* poPointIter = getPointIterator(); OGRPoint p1, p2, p3; if( poPointIter->getNextPoint(&p1) && poPointIter->getNextPoint(&p2) ) { while( poPointIter->getNextPoint(&p3) ) { double crossproduct = (p2.getX() - p1.getX()) * (p3.getY() - p2.getY()) - (p2.getY() - p1.getY()) * (p3.getX() - p2.getX()); if( crossproduct > 0 ) { bRet = FALSE; break; } p1.setX(p2.getX()); p1.setY(p2.getY()); p2.setX(p3.getX()); p2.setY(p3.getY()); } } delete poPointIter; return bRet; } /************************************************************************/ /* CastToCompoundCurve() */ /************************************************************************/ /** * \brief Cast to compound curve * * The passed in geometry is consumed and a new one returned (or NULL in case * of failure) * * @param poCurve the input geometry - ownership is passed to the method. * @return new geometry * * @since GDAL 2.0 */ OGRCompoundCurve* OGRCurve::CastToCompoundCurve(OGRCurve* poCurve) { OGRCompoundCurve* poCC = new OGRCompoundCurve(); if( poCurve->getGeometryType() == wkbLineString ) poCurve = CastToLineString(poCurve); if( !poCurve->IsEmpty() && poCC->addCurveDirectly(poCurve) != OGRERR_NONE ) { delete poCC; delete poCurve; return NULL; } poCC->assignSpatialReference(poCurve->getSpatialReference()); return poCC; } /************************************************************************/ /* CastToLineString() */ /************************************************************************/ /** * \brief Cast to linestring * * The passed in geometry is consumed and a new one returned (or NULL in case * of failure) * * @param poCurve the input geometry - ownership is passed to the method. * @return new geometry. * * @since GDAL 2.0 */ OGRLineString* OGRCurve::CastToLineString(OGRCurve* poCurve) { OGRCurveCasterToLineString pfn = poCurve->GetCasterToLineString(); return pfn(poCurve); } /************************************************************************/ /* CastToLinearRing() */ /************************************************************************/ /** * \brief Cast to linear ring * * The passed in geometry is consumed and a new one returned (or NULL in case * of failure) * * @param poCurve the input geometry - ownership is passed to the method. * @return new geometry. * * @since GDAL 2.0 */ OGRLinearRing* OGRCurve::CastToLinearRing(OGRCurve* poCurve) { OGRCurveCasterToLinearRing pfn = poCurve->GetCasterToLinearRing(); return pfn(poCurve); } /************************************************************************/ /* ContainsPoint() */ /************************************************************************/ /** * \brief Returns if a point is contained in a (closed) curve. * * Final users should use OGRGeometry::Contains() instead. * * @param p the point to test * @return TRUE if it is inside the curve, FALSE otherwise or -1 if unknown. * * @since GDAL 2.0 */ int OGRCurve::ContainsPoint( CPL_UNUSED const OGRPoint* p ) const { return -1; } /************************************************************************/ /* ~OGRPointIterator() */ /************************************************************************/ OGRPointIterator::~OGRPointIterator() { } /** * \fn OGRBoolean OGRPointIterator::getNextPoint(OGRPoint* p); * * \brief Returns the next point followed by the iterator. * * @param p point to fill. * * @return TRUE in case of success, or FALSE if the end of the curve is reached. * * @since GDAL 2.0 */ /************************************************************************/ /* destroy() */ /************************************************************************/ /** * \brief Destroys a point iterator. * * @since GDAL 2.0 */ void OGRPointIterator::destroy(OGRPointIterator* poIter) { delete poIter; }