ogr_api.cpp

mitab,读取MapInfo的地图文件

/******************************************************************************
 * $Id: ogr_api.cpp 12043 2007-09-03 17:58:51Z mloskot $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  C API Functions that don't correspond one-to-one with C++ 
 *           methods, such as the "simplified" geometry access functions.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2002, 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_api.h"
#include "cpl_error.h"

/************************************************************************/
/*                        OGR_G_GetPointCount()                         */
/************************************************************************/
/**
 * Fetch number of points from a geometry.
 *
 * @param hGeom handle to the geometry from which to get the number of points.
 * @return the number of points.
 */

int OGR_G_GetPointCount( OGRGeometryH hGeom )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
        return 1;

      case wkbLineString:
      {
          OGRLineString *poLine = (OGRLineString *) hGeom;
          return poLine->getNumPoints();
      }

      default:
        return 0;
    }
}

/************************************************************************/
/*                             OGR_G_GetX()                             */
/************************************************************************/
/**
 * Fetch the x coordinate of a point from a geometry.
 *
 * @param hGeom handle to the geometry from which to get the x coordinate.
 * @param i point to get the x coordinate.
 * @return the X coordinate of this point. 
 */

double OGR_G_GetX( OGRGeometryH hGeom, int i )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          if( i == 0 )
              return ((OGRPoint *) hGeom)->getX();
          else
              return 0.0;
      }

      case wkbLineString:
        return ((OGRLineString *) hGeom)->getX( i );

      default:
        return 0.0;
    }
}

/************************************************************************/
/*                             OGR_G_GetY()                             */
/************************************************************************/
/**
 * Fetch the x coordinate of a point from a geometry.
 *
 * @param hGeom handle to the geometry from which to get the y coordinate.
 * @param i point to get the Y coordinate.
 * @return the Y coordinate of this point. 
 */

double OGR_G_GetY( OGRGeometryH hGeom, int i )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          if( i == 0 )
              return ((OGRPoint *) hGeom)->getY();
          else
              return 0.0;
      }

      case wkbLineString:
          return ((OGRLineString *) hGeom)->getY( i );

      default:
        return 0.0;
    }
}

/************************************************************************/
/*                             OGR_G_GetZ()                             */
/************************************************************************/
/**
 * Fetch the z coordinate of a point from a geometry.
 *
 * @param hGeom handle to the geometry from which to get the Z coordinate.
 * @param i point to get the Z coordinate.
 * @return the Z coordinate of this point. 
 */

double OGR_G_GetZ( OGRGeometryH hGeom, int i )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          if( i == 0 )
              return ((OGRPoint *) hGeom)->getZ();
          else
              return 0.0;
      }

      case wkbLineString:
          return ((OGRLineString *) hGeom)->getZ( i );

      default:
          return 0.0;
    }
}

/************************************************************************/
/*                           OGR_G_GetPoint()                           */
/************************************************************************/

/**
 * Fetch a point in line string or a point geometry.
 *
 * @param hGeom handle to the geometry from which to get the coordinates.
 * @param i the vertex to fetch, from 0 to getNumPoints()-1, zero for a point.
 * @param pdfX value of x coordinate.
 * @param pdfY value of y coordinate.
 * @param pdfZ value of z coordinate.
 */

void OGR_G_GetPoint( OGRGeometryH hGeom, int i, 
                     double *pdfX, double *pdfY, double *pdfZ )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          CPLAssert( i == 0 );
          if( i == 0 )
          {
              *pdfX = ((OGRPoint *)hGeom)->getX();
              *pdfY = ((OGRPoint *)hGeom)->getY();
              if( pdfZ != NULL )
                  *pdfZ = ((OGRPoint *)hGeom)->getZ();
          }
      }
      break;

      case wkbLineString:
      {
          *pdfX = ((OGRLineString *) hGeom)->getX( i );
          *pdfY = ((OGRLineString *) hGeom)->getY( i );
          if( pdfZ != NULL )
              *pdfZ = ((OGRLineString *) hGeom)->getZ( i );
      }
      break;

      default:
        CPLAssert( FALSE );
        break;
    }
}

/************************************************************************/
/*                           OGR_G_SetPoint()                           */
/************************************************************************/
/**
 * Set the location of a vertex in a point or linestring geometry.
 *
 * If iPoint is larger than the number of existing
 * points in the linestring, the point count will be increased to
 * accomodate the request.
 *
 * @param hGeom handle to the geometry to add a vertex to.
 * @param i the index of the vertex to assign (zero based) or
 *  zero for a point.
 * @param dfX input X coordinate to assign.
 * @param dfY input Y coordinate to assign.
 * @param dfZ input Z coordinate to assign (defaults to zero).
 */

void OGR_G_SetPoint( OGRGeometryH hGeom, int i, 
                     double dfX, double dfY, double dfZ )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          CPLAssert( i == 0 );
          if( i == 0 )
          {
              ((OGRPoint *) hGeom)->setX( dfX );
              ((OGRPoint *) hGeom)->setY( dfY );
              ((OGRPoint *) hGeom)->setZ( dfZ );
          }
      }
      break;

      case wkbLineString:
        ((OGRLineString *) hGeom)->setPoint( i, dfX, dfY, dfZ );
        break;

      default:
        CPLAssert( FALSE );
        break;
    }
}

/************************************************************************/
/*                         OGR_G_SetPoint_2D()                          */
/************************************************************************/
/**
 * Set the location of a vertex in a point or linestring geometry.
 *
 * If iPoint is larger than the number of existing
 * points in the linestring, the point count will be increased to
 * accomodate the request.
 *
 * @param hGeom handle to the geometry to add a vertex to.
 * @param i the index of the vertex to assign (zero based) or
 *  zero for a point.
 * @param dfX input X coordinate to assign.
 * @param dfY input Y coordinate to assign.
 */

void OGR_G_SetPoint_2D( OGRGeometryH hGeom, int i, 
                        double dfX, double dfY )
    
{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          CPLAssert( i == 0 );
          if( i == 0 )
          {
              ((OGRPoint *) hGeom)->setX( dfX );
              ((OGRPoint *) hGeom)->setY( dfY );
          }
      }
      break;

      case wkbLineString:
        ((OGRLineString *) hGeom)->setPoint( i, dfX, dfY );
        break;

      default:
        CPLAssert( FALSE );
        break;
    }
}

/************************************************************************/
/*                           OGR_G_AddPoint()                           */
/************************************************************************/
/**
 * Add a point to a geometry (line string or point).
 *
 * The vertex count of the line string is increased by one, and assigned from
 * the passed location value.
 *
 * @param hGeom handle to the geometry to add a point to.
 * @param dfX x coordinate of point to add.
 * @param dfY y coordinate of point to add.
 * @param dfZ z coordinate of point to add.
 */

void OGR_G_AddPoint( OGRGeometryH hGeom, 
                     double dfX, double dfY, double dfZ )

{
    switch( wkbFlatten(((OGRGeometry *) hGeom)->getGeometryType()) )
    {
      case wkbPoint:
      {
          ((OGRPoint *) hGeom)->setX( dfX );
          ((OGRPoint *) hGeom)->setY( dfY );
          ((OGRPoint *) hGeom)->setZ( dfZ );
      }
      break;

      case wkbLineString:
        ((OGRLineString *) hGeom)->addPoint( dfX, dfY, dfZ );
        break;

      default:
        CPLAssert( FALSE );
        break;
    }
}