virtual Acad::ErrorStatus getOsnapInfo(
AcDbEntity* pickedObject,
Adesk::GsMarker gsSelectionMark,
const AcGePoint3d& pickPoint,
const AcGePoint3d& lastPoint,
const AcGeMatrix3d& viewXform,
AcArray<AcGePoint3d>& snapPoints,
AcArray<int>& geomIdsForPts,
AcArray<AcGeCurve3d*>& snapCurves,
AcArray<int>& geomIdsForLines)
{
// Specialised implementation for AcDbPolylines:
// Parametrisation of AcDbPolylines is different: each whole numbered paramater appears
// at a vertex, so we cannot simply divide by three to get the correct parameter.
// Protocol Extension insures that the following assertion is always
// true, but check in non-prod versions just to be safe.
assert( pickedObject->isKindOf( AcDbPolyline::desc() ));
// but in production, a hard cast is fastest
AcDbPolyline *pPline = (AcDbPolyline*)pickedObject;
Acad::ErrorStatus es;
if ( bSnapToSegments )
{
// Snap to a third of each of the segments
unsigned int numSegs = pPline->numVerts() - 1;
AcGeLineSeg3d segLn;
AcGeCircArc3d segArc;
double startParam, endParam, newParam, dist;
AcGePoint3d pt;
for ( unsigned int idx = 0; idx < numSegs; idx++ )
{
switch( pPline->segType( idx ))
{
case AcDbPolyline::kLine:
es=pPline->getLineSegAt( idx, segLn );
startParam = segLn.paramOf( segLn.startPoint() );
endParam = segLn.paramOf( segLn.endPoint() );
snapPoints.append(segLn.evalPoint( startParam + ((endParam - startParam) / 3 )));
snapPoints.append(segLn.evalPoint( startParam + ((endParam - startParam) * 2 / 3 )));
break;
case AcDbPolyline::kArc:
es=pPline->getArcSegAt( idx, segArc );
startParam = segArc.paramOf( segArc.startPoint() );
endParam = segArc.paramOf( segArc.endPoint() );
dist = segArc.length( startParam, endParam );
newParam = segArc.paramAtLength( startParam, dist / 3 );
snapPoints.append( segArc.evalPoint( newParam ));
newParam = segArc.paramAtLength( startParam, dist * 2 / 3 );
snapPoints.append( segArc.evalPoint( newParam ));
break;
default:
break;
}
}
}
else {
double endParam;
AcGePoint3d pt;
double dist;
es=pPline->getEndParam( endParam );
es=pPline->getDistAtParam( endParam, dist );
es=pPline->getPointAtDist( dist / 3, pt );
assert(Acad::eOk==es);
snapPoints.append( pt );
es=pPline->getPointAtDist( dist * 2 / 3, pt );
assert(Acad::eOk==es);
snapPoints.append( pt );
if ( pPline->isClosed() )
{
es=pPline->getStartPoint( pt );
snapPoints.append( pt );
}
}
return Acad::eOk;
}
