Xref clipping

Anonymous — Thu, 25 Apr 2002 13:16:23 GMT

I am working on a few utilities that deal with xrefs and want to be able to
handle clipped boundaries.... The following code works pretty well with one
exception. If the xref is moved from its original insertion BEFORE the xclip
is applied then the points gathered in the following manner are off by the
distance the xref was moved. The 'ACAD_FILTER' dictionary seems to contain
the data to create a transformation matrix to use for correcting this,
anyone have any suggestions on the best way to retrieve this data and place
it in an AcGeMatrix3d or of another method to retrieve the difference in the
points returned by getDefinition and the current insertion point of the
block reference? I am not really trying to draw the clipped boundary,
AutoCAD can do that, this is just a test to see if I can get the proper
points that make up the boundary.

bool drawClippedBoundary(AcDbObjectId xrefID){
AcDbObjectId dictionaryID,filterID, spatialID;
// data values for spatial filter....
AcGePoint2dArray points;
AcGeVector3d normVector;
double elevation,frontClip,backClip;
Adesk::Boolean enabled;

AcDbObjectPointer pBlock(xrefID,AcDb::kForRead);
if(Acad::eOk == pBlock.openStatus()){
dictionaryID = pBlock->extensionDictionary();
AcDbObjectPointer
pDictionary(dictionaryID,AcDb::kForRead);
if(Acad::eOk == pDictionary.openStatus()){
pDictionary->getAt("ACAD_FILTER",filterID);
AcDbObjectPointer pFilter(filterID,AcDb::kForRead);
if(Acad::eOk == pFilter.openStatus()){
pFilter->getAt("SPATIAL",spatialID);
AcDbObjectPointer pSpatial(spatialID,AcDb::kForRead);
if(Acad::eOk == pSpatial.openStatus()){
if(Acad::eOk ==
pSpatial->getDefinition(points,normVector,elevation,frontClip,backClip,enabl
ed)){
// The following is temporary code to add a polyline around a
// clipped xref. This is for testing purposes only!
AcDbPolyline *pLine = new AcDbPolyline;
int pointLoop;
for(pointLoop = 0; pointLoop < points.logicalLength(); pointLoop++){
pLine->addVertexAt(0,points[pointLoop]);
}
pLine->setClosed(true);
pLine->transformBy(pBlock->blockTransform());
// get the modelspace record ID....
AcDbBlockTable *pBlockTable;
AcDbObjectId modelSpaceID, pLineID;

acdbHostApplicationServices()->workingDatabase()->getSymbolTable(pBlockTable
,AcDb::kForRead);
pBlockTable->getAt(ACDB_MODEL_SPACE,modelSpaceID);
AcDbObjectPointer
pModelSpace(modelSpaceID,AcDb::kForWrite);
if(Acad::eOk == pModelSpace.openStatus()){
if(Acad::eOk != pModelSpace->appendAcDbEntity(pLineID, pLine)){
delete pLine;
return false;
}
}
pLine->close();
pBlockTable->close();
return true;
}
}
}
}
}
return false;
}

topic Xref clipping in ObjectARX Forum

Xref clipping