unsigned char *DGNGetLinkage( DGNHandle hDGN, DGNElemCore *psElement,
int iIndex, int *pnLinkageType,
int *pnEntityNum, int *pnMSLink, int *pnLength )
{
int nAttrOffset;
int iLinkage, nLinkSize;
for( iLinkage=0, nAttrOffset=0;
(nLinkSize = DGNGetAttrLinkSize( hDGN, psElement, nAttrOffset)) != 0;
iLinkage++, nAttrOffset += nLinkSize )
{
if( iLinkage == iIndex )
{
int nLinkageType=0, nEntityNum=0, nMSLink = 0;
CPLAssert( nLinkSize > 4 );
if( psElement->attr_data[nAttrOffset+0] == 0x00
&& (psElement->attr_data[nAttrOffset+1] == 0x00
|| psElement->attr_data[nAttrOffset+1] == 0x80) )
{
nLinkageType = DGNLT_DMRS;
nEntityNum = psElement->attr_data[nAttrOffset+2]
+ psElement->attr_data[nAttrOffset+3] * 256;
nMSLink = psElement->attr_data[nAttrOffset+4]
+ psElement->attr_data[nAttrOffset+5] * 256
+ psElement->attr_data[nAttrOffset+6] * 65536;
}
else
nLinkageType = psElement->attr_data[nAttrOffset+2]
+ psElement->attr_data[nAttrOffset+3] * 256;
// Possibly an external database linkage?
if( nLinkSize == 16 && nLinkageType != DGNLT_SHAPE_FILL )
{
nEntityNum = psElement->attr_data[nAttrOffset+6]
+ psElement->attr_data[nAttrOffset+7] * 256;
nMSLink = psElement->attr_data[nAttrOffset+8]
+ psElement->attr_data[nAttrOffset+9] * 256
+ psElement->attr_data[nAttrOffset+10] * 65536
+ psElement->attr_data[nAttrOffset+11] * 65536 * 256;
}
if( pnLinkageType != NULL )
*pnLinkageType = nLinkageType;
if( pnEntityNum != NULL )
*pnEntityNum = nEntityNum;
if( pnMSLink != NULL )
*pnMSLink = nMSLink;
if( pnLength != NULL )
*pnLength = nLinkSize;
return psElement->attr_data + nAttrOffset;
}
}
return NULL;
}
unsigned char *DGNGetLinkage( DGNHandle hDGN, DGNElemCore *psElement,
int iIndex, int *pnLinkageType,
int *pnEntityNum, int *pnMSLink, int *pnLength )
{
int nLinkSize = 0;
for( int iLinkage=0, nAttrOffset=0;
(nLinkSize = DGNGetAttrLinkSize( hDGN, psElement, nAttrOffset)) != 0;
iLinkage++, nAttrOffset += nLinkSize )
{
if( iLinkage == iIndex )
{
if( nLinkSize <= 4 )
{
CPLError(CE_Failure, CPLE_AssertionFailed, "nLinkSize <= 4");
return nullptr;
}
if( nLinkSize + nAttrOffset > psElement->attr_bytes )
{
CPLError(CE_Failure, CPLE_AssertionFailed,
"nLinkSize + nAttrOffset > psElement->attr_bytes");
return nullptr;
}
int nLinkageType = 0;
int nEntityNum = 0;
int nMSLink = 0;
if( psElement->attr_bytes >= nAttrOffset + 7 &&
psElement->attr_data[nAttrOffset+0] == 0x00
&& (psElement->attr_data[nAttrOffset+1] == 0x00
|| psElement->attr_data[nAttrOffset+1] == 0x80) )
{
nLinkageType = DGNLT_DMRS;
nEntityNum = psElement->attr_data[nAttrOffset+2]
+ psElement->attr_data[nAttrOffset+3] * 256;
nMSLink = psElement->attr_data[nAttrOffset+4]
+ psElement->attr_data[nAttrOffset+5] * 256
+ psElement->attr_data[nAttrOffset+6] * 65536;
}
else if( psElement->attr_bytes >= nAttrOffset + 4 )
nLinkageType = psElement->attr_data[nAttrOffset+2]
+ psElement->attr_data[nAttrOffset+3] * 256;
// Possibly an external database linkage?
if( nLinkSize == 16 && nLinkageType != DGNLT_SHAPE_FILL &&
psElement->attr_bytes >= nAttrOffset + 12 )
{
nEntityNum = psElement->attr_data[nAttrOffset+6]
+ psElement->attr_data[nAttrOffset+7] * 256;
nMSLink = psElement->attr_data[nAttrOffset+8]
| (psElement->attr_data[nAttrOffset+9] << 8)
| (psElement->attr_data[nAttrOffset+10] << 16)
| (psElement->attr_data[nAttrOffset+11] << 24);
}
if( pnLinkageType != nullptr )
*pnLinkageType = nLinkageType;
if( pnEntityNum != nullptr )
*pnEntityNum = nEntityNum;
if( pnMSLink != nullptr )
*pnMSLink = nMSLink;
if( pnLength != nullptr )
*pnLength = nLinkSize;
return psElement->attr_data + nAttrOffset;
}
}
return nullptr;
}
