shpopen.c

Source code, and some other odds and ends can be downloaded from http://shapelib.maptools.org/dl.

                if( bBigEndian ) SwapWord( 4, psShape->panPartType+i );
            }

            nOffset += 4*nParts;
        }
        
/* -------------------------------------------------------------------- */
/*      Copy out the vertices from the record.                          */
/* -------------------------------------------------------------------- */
	for( i = 0; i < nPoints; i++ )
	{
	    memcpy(psShape->padfX + i,
		   pabyRec + nOffset + i * 16,
		   8 );

	    memcpy(psShape->padfY + i,
		   pabyRec + nOffset + i * 16 + 8,
		   8 );

	    if( bBigEndian ) SwapWord( 8, psShape->padfX + i );
	    if( bBigEndian ) SwapWord( 8, psShape->padfY + i );
	}

        nOffset += 16*nPoints;
        
/* -------------------------------------------------------------------- */
/*      If we have a Z coordinate, collect that now.                    */
/* -------------------------------------------------------------------- */
        if( psShape->nSHPType == SHPT_POLYGONZ
            || psShape->nSHPType == SHPT_ARCZ
            || psShape->nSHPType == SHPT_MULTIPATCH )
        {
            memcpy( &(psShape->dfZMin), pabyRec + nOffset, 8 );
            memcpy( &(psShape->dfZMax), pabyRec + nOffset + 8, 8 );
            
            if( bBigEndian ) SwapWord( 8, &(psShape->dfZMin) );
            if( bBigEndian ) SwapWord( 8, &(psShape->dfZMax) );
            
            for( i = 0; i < nPoints; i++ )
            {
                memcpy( psShape->padfZ + i,
                        pabyRec + nOffset + 16 + i*8, 8 );
                if( bBigEndian ) SwapWord( 8, psShape->padfZ + i );
            }

            nOffset += 16 + 8*nPoints;
        }

/* -------------------------------------------------------------------- */
/*      If we have a M measure value, then read it now.  We assume      */
/*      that the measure can be present for any shape if the size is    */
/*      big enough, but really it will only occur for the Z shapes      */
/*      (options), and the M shapes.                                    */
/* -------------------------------------------------------------------- */
        if( psSHP->panRecSize[hEntity]+8 >= nOffset + 16 + 8*nPoints )
        {
            memcpy( &(psShape->dfMMin), pabyRec + nOffset, 8 );
            memcpy( &(psShape->dfMMax), pabyRec + nOffset + 8, 8 );
            
            if( bBigEndian ) SwapWord( 8, &(psShape->dfMMin) );
            if( bBigEndian ) SwapWord( 8, &(psShape->dfMMax) );
            
            for( i = 0; i < nPoints; i++ )
            {
                memcpy( psShape->padfM + i,
                        pabyRec + nOffset + 16 + i*8, 8 );
                if( bBigEndian ) SwapWord( 8, psShape->padfM + i );
            }
        }
        
    }

/* ==================================================================== */
/*  Extract vertices for a MultiPoint.					*/
/* ==================================================================== */
    else if( psShape->nSHPType == SHPT_MULTIPOINT
             || psShape->nSHPType == SHPT_MULTIPOINTM
             || psShape->nSHPType == SHPT_MULTIPOINTZ )
    {
	int32		nPoints;
	int    		i, nOffset;

	memcpy( &nPoints, pabyRec + 44, 4 );
	if( bBigEndian ) SwapWord( 4, &nPoints );

	psShape->nVertices = nPoints;
        psShape->padfX = (double *) calloc(nPoints,sizeof(double));
        psShape->padfY = (double *) calloc(nPoints,sizeof(double));
        psShape->padfZ = (double *) calloc(nPoints,sizeof(double));
        psShape->padfM = (double *) calloc(nPoints,sizeof(double));

	for( i = 0; i < nPoints; i++ )
	{
	    memcpy(psShape->padfX+i, pabyRec + 48 + 16 * i, 8 );
	    memcpy(psShape->padfY+i, pabyRec + 48 + 16 * i + 8, 8 );

	    if( bBigEndian ) SwapWord( 8, psShape->padfX + i );
	    if( bBigEndian ) SwapWord( 8, psShape->padfY + i );
	}

        nOffset = 48 + 16*nPoints;
        
/* -------------------------------------------------------------------- */
/*	Get the X/Y bounds.						*/
/* -------------------------------------------------------------------- */
        memcpy( &(psShape->dfXMin), pabyRec + 8 +  4, 8 );
        memcpy( &(psShape->dfYMin), pabyRec + 8 + 12, 8 );
        memcpy( &(psShape->dfXMax), pabyRec + 8 + 20, 8 );
        memcpy( &(psShape->dfYMax), pabyRec + 8 + 28, 8 );

	if( bBigEndian ) SwapWord( 8, &(psShape->dfXMin) );
	if( bBigEndian ) SwapWord( 8, &(psShape->dfYMin) );
	if( bBigEndian ) SwapWord( 8, &(psShape->dfXMax) );
	if( bBigEndian ) SwapWord( 8, &(psShape->dfYMax) );

/* -------------------------------------------------------------------- */
/*      If we have a Z coordinate, collect that now.                    */
/* -------------------------------------------------------------------- */
        if( psShape->nSHPType == SHPT_MULTIPOINTZ )
        {
            memcpy( &(psShape->dfZMin), pabyRec + nOffset, 8 );
            memcpy( &(psShape->dfZMax), pabyRec + nOffset + 8, 8 );
            
            if( bBigEndian ) SwapWord( 8, &(psShape->dfZMin) );
            if( bBigEndian ) SwapWord( 8, &(psShape->dfZMax) );
            
            for( i = 0; i < nPoints; i++ )
            {
                memcpy( psShape->padfZ + i,
                        pabyRec + nOffset + 16 + i*8, 8 );
                if( bBigEndian ) SwapWord( 8, psShape->padfZ + i );
            }

            nOffset += 16 + 8*nPoints;
        }

/* -------------------------------------------------------------------- */
/*      If we have a M measure value, then read it now.  We assume      */
/*      that the measure can be present for any shape if the size is    */
/*      big enough, but really it will only occur for the Z shapes      */
/*      (options), and the M shapes.                                    */
/* -------------------------------------------------------------------- */
        if( psSHP->panRecSize[hEntity]+8 >= nOffset + 16 + 8*nPoints )
        {
            memcpy( &(psShape->dfMMin), pabyRec + nOffset, 8 );
            memcpy( &(psShape->dfMMax), pabyRec + nOffset + 8, 8 );
            
            if( bBigEndian ) SwapWord( 8, &(psShape->dfMMin) );
            if( bBigEndian ) SwapWord( 8, &(psShape->dfMMax) );
            
            for( i = 0; i < nPoints; i++ )
            {
                memcpy( psShape->padfM + i,
                        pabyRec + nOffset + 16 + i*8, 8 );
                if( bBigEndian ) SwapWord( 8, psShape->padfM + i );
            }
        }
    }

/* ==================================================================== */
/*      Extract vertices for a point.                                   */
/* ==================================================================== */
    else if( psShape->nSHPType == SHPT_POINT
             || psShape->nSHPType == SHPT_POINTM
             || psShape->nSHPType == SHPT_POINTZ )
    {
        int	nOffset;
        
	psShape->nVertices = 1;
        psShape->padfX = (double *) calloc(1,sizeof(double));
        psShape->padfY = (double *) calloc(1,sizeof(double));
        psShape->padfZ = (double *) calloc(1,sizeof(double));
        psShape->padfM = (double *) calloc(1,sizeof(double));

	memcpy( psShape->padfX, pabyRec + 12, 8 );
	memcpy( psShape->padfY, pabyRec + 20, 8 );

	if( bBigEndian ) SwapWord( 8, psShape->padfX );
	if( bBigEndian ) SwapWord( 8, psShape->padfY );

        nOffset = 20 + 8;
        
/* -------------------------------------------------------------------- */
/*      If we have a Z coordinate, collect that now.                    */
/* -------------------------------------------------------------------- */
        if( psShape->nSHPType == SHPT_POINTZ )
        {
            memcpy( psShape->padfZ, pabyRec + nOffset, 8 );
        
            if( bBigEndian ) SwapWord( 8, psShape->padfZ );
            
            nOffset += 8;
        }

/* -------------------------------------------------------------------- */
/*      If we have a M measure value, then read it now.  We assume      */
/*      that the measure can be present for any shape if the size is    */
/*      big enough, but really it will only occur for the Z shapes      */
/*      (options), and the M shapes.                                    */
/* -------------------------------------------------------------------- */
        if( psSHP->panRecSize[hEntity]+8 >= nOffset + 8 )
        {
            memcpy( psShape->padfM, pabyRec + nOffset, 8 );
        
            if( bBigEndian ) SwapWord( 8, psShape->padfM );
        }

/* -------------------------------------------------------------------- */
/*      Since no extents are supplied in the record, we will apply      */
/*      them from the single vertex.                                    */
/* -------------------------------------------------------------------- */
        psShape->dfXMin = psShape->dfXMax = psShape->padfX[0];
        psShape->dfYMin = psShape->dfYMax = psShape->padfY[0];
        psShape->dfZMin = psShape->dfZMax = psShape->padfZ[0];
        psShape->dfMMin = psShape->dfMMax = psShape->padfM[0];
    }

    return( psShape );
}

/************************************************************************/
/*                            SHPTypeName()                             */
/************************************************************************/

const char SHPAPI_CALL1(*)
SHPTypeName( int nSHPType )

{
    switch( nSHPType )
    {
      case SHPT_NULL:
        return "NullShape";

      case SHPT_POINT:
        return "Point";

      case SHPT_ARC:
        return "Arc";

      case SHPT_POLYGON:
        return "Polygon";

      case SHPT_MULTIPOINT:
        return "MultiPoint";
        
      case SHPT_POINTZ:
        return "PointZ";

      case SHPT_ARCZ:
        return "ArcZ";

      case SHPT_POLYGONZ:
        return "PolygonZ";

      case SHPT_MULTIPOINTZ:
        return "MultiPointZ";
        
      case SHPT_POINTM:
        return "PointM";

      case SHPT_ARCM:
        return "ArcM";

      case SHPT_POLYGONM:
        return "PolygonM";

      case SHPT_MULTIPOINTM:
        return "MultiPointM";

      case SHPT_MULTIPATCH:
        return "MultiPatch";

      default:
        return "UnknownShapeType";
    }
}

/************************************************************************/
/*                          SHPPartTypeName()                           */
/************************************************************************/

const char SHPAPI_CALL1(*)
SHPPartTypeName( int nPartType )

{
    switch( nPartType )
    {
      case SHPP_TRISTRIP:
        return "TriangleStrip";
        
      case SHPP_TRIFAN:
        return "TriangleFan";

      case SHPP_OUTERRING:
        return "OuterRing";

      case SHPP_INNERRING:
        return "InnerRing";

      case SHPP_FIRSTRING:
        return "FirstRing";

      case SHPP_RING:
        return "Ring";

      default:
        return "UnknownPartType";
    }
}

/************************************************************************/
/*                          SHPDestroyObject()                          */
/************************************************************************/

void SHPAPI_CALL
SHPDestroyObject( SHPObject * psShape )

{
    if( psShape == NULL )
        return;
    
    if( psShape->padfX != NULL )
        free( psShape->padfX );
    if( psShape->padfY != NULL )
        free( psShape->padfY );
    if( psShape->padfZ != NULL )
        free( psShape->padfZ );
    if( psShape->padfM != NULL )
        free( psShape->padfM );

    if( psShape->panPartStart != NULL )
        free( psShape->panPartStart );
    if( psShape->panPartType != NULL )
        free( psShape->panPartType );

    free( psShape );
}