Acad::ErrorStatus Custom::getOsnapPoints( AcDb::OsnapMode osnapMode,
int gsSelectionMark,
const AcGePoint3d& pickPoint,
const AcGePoint3d& lastPoint,
const AcGeMatrix3d& viewXform,
AcGePoint3dArray& snapPoints,
AcDbIntArray& geomIds) const {
assertReadEnabled();
switch(osnapMode) {
case AcDb::kOsModeNear:
return osnapNear( pickPoint, viewXform, snapPoints );
case AcDb::kOsModeEnd:
case AcDb::kOsModeMid:
case AcDb::kOsModePerp:
case AcDb::kOsModeCen:
return osnapCenter( pickPoint, snapPoints );
case AcDb::kOsModeQuad:
return osnapQuadrant( pickPoint, snapPoints );
case AcDb::kOsModeNode:
case AcDb::kOsModeIns:
case AcDb::kOsModeTan:
default:
break;
}
return Acad::eInvalidInput;
}
Acad::ErrorStatus Custom::osnapNear( const AcGePoint3d& pickPoint,
const AcGeMatrix3d& viewXform,
AcGePoint3dArray& snapPoints ) const {
AcGeVector3d viewDir( viewXform( Z, 0 ), 
viewXform( Z, 1 ),
viewXform( Z, 2 ) );
Acad::ErrorStatus es = Acad::eOk;
AcGePoint3d center1, center2, pt;
AcGeVector3d normal( 0.0, 0.0, 1.0 );
AcGeVector3d axis = mEndPoint - mStartPoint;
axis.normalize();
center1 = mStartPoint + (axis * mRadius1 );
center2 = mEndPoint - (axis * mRadius2 );
AcGeCircArc3d *circle1 = new AcGeCircArc3d( center1, normal, mRadius1 );
AcGeCircArc3d *circle2 = new AcGeCircArc3d( center2, normal, mRadius2 );
if( center1.distanceTo( pickPoint ) < center2.distanceTo( pickPoint ) ) {
pt = circle1->projClosestPointTo( pickPoint, viewDir );
} else {
pt = circle2->projClosestPointTo( pickPoint, viewDir );
}
snapPoints.append( pt );
delete circle1;
delete circle2;
return es;
}
Acad::ErrorStatus Custom::osnapCenter( const AcGePoint3d& pickPoint,
AcGePoint3dArray& snapPoints ) const {
AcGePoint3d center1, center2, pt;
AcGeVector3d axis = mEndPoint - mStartPoint;
axis.normalize();
center1 = mStartPoint + (axis * mRadius1 );
center2 = mEndPoint - (axis * mRadius2 );
if( center1.distanceTo( pickPoint ) < center2.distanceTo( pickPoint ) ) {
snapPoints.append( center1 );
} else {
snapPoints.append( center2 );
}
return Acad::eOk;
}
Acad::ErrorStatus Custom::osnapQuadrant( const AcGePoint3d& pickPoint,
AcGePoint3dArray& snapPoints ) const {
AcGePoint3d center1, center2, pt, q1, q2, q3, q4;
AcGeVector3d normal( 0.0, 0.0, 1.0 );
AcGeVector3d ox( 1.0, 0.0, 0.0 );
AcGeVector3d oy( 0.0, 1.0, 0.0 );
AcGeVector3d axis = mEndPoint - mStartPoint;
axis.normalize();
center1 = mStartPoint + (axis * mRadius1 );
center2 = mEndPoint - (axis * mRadius2 );
if( center1.distanceTo( pickPoint ) < center2.distanceTo( pickPoint ) ) {
q1 = center1 + ( ox * mRadius1 );
q2 = center1 + ( oy * mRadius1 );
q3 = center1 - ( ox * mRadius1 );
q4 = center1 - ( oy * mRadius1 );
if( q1.distanceTo( pickPoint ) < q2.distanceTo( pickPoint ) &&
q1.distanceTo( pickPoint ) < q4.distanceTo( pickPoint ) ) {
pt = q1;
} else
if( q2.distanceTo( pickPoint ) < q1.distanceTo( pickPoint ) &&
q2.distanceTo( pickPoint ) < q3.distanceTo( pickPoint ) ) {
pt = q2;
} else
if( q3.distanceTo( pickPoint ) < q2.distanceTo( pickPoint ) &&
q3.distanceTo( pickPoint ) < q4.distanceTo( pickPoint ) ) {
pt = q3;
} else {
pt = q4;
}
} else {
q1 = center2 + ( ox * mRadius2 );
q2 = center2 + ( oy * mRadius2 );
q3 = center2 - ( ox * mRadius2 );
q4 = center2 - ( oy * mRadius2 );
if( q1.distanceTo( pickPoint ) < q2.distanceTo( pickPoint ) &&
q1.distanceTo( pickPoint ) < q4.distanceTo( pickPoint ) ) {
pt = q1;
} else
if( q2.distanceTo( pickPoint ) < q1.distanceTo( pickPoint ) &&
q2.distanceTo( pickPoint ) < q3.distanceTo( pickPoint ) ) {
pt = q2;
} else
if( q3.distanceTo( pickPoint ) < q2.distanceTo( pickPoint ) &&
q3.distanceTo( pickPoint ) < q4.distanceTo( pickPoint ) ) {
pt = q3;
} else {
pt = q4;
}
}
snapPoints.append( pt );
return Acad::eOk;
}
static Acad::ErrorStatus intLine( Custom* custom, 
const AcDbLine* line,
AcDb::Intersect intType,
const AcGePlane* projPlane,
AcGePoint3dArray& points);
static Acad::ErrorStatus intLine( Custom* custom, 
const AcGeLineSeg3d line,
AcGePoint3dArray& points);
static Acad::ErrorStatus intLine( Custom* custom, 
const AcGeLineSeg3d line,
AcGePoint3dArray& points) {
Acad::ErrorStatus es = Acad::eOk;
AcGePoint3d startPoint, endPoint, center1, center2, pt1, pt2;
startPoint = custom->getStartPoint();
endPoint = custom->getEndPoint();
AcGeVector3d normal( 0.0, 0.0, 1.0 );
AcGeVector3d axis = endPoint - startPoint;
axis.normalize();
double radius1 = custom->getRadius1();
double radius2 = custom->getRadius2();
int noOfPoints;
center1 = startPoint + (axis * radius1 );
center2 = endPoint - (axis * radius2 );
AcGeCircArc3d *circle1 = new AcGeCircArc3d( center1, normal, radius1 );
AcGeCircArc3d *circle2 = new AcGeCircArc3d( center2, normal, radius2 );
if( circle1->intersectWith( line, noOfPoints, pt1, pt2 ) ) {
points.append( pt1 );
points.append( pt2 );
} else
if( circle2->intersectWith( line, noOfPoints, pt1, pt2 ) ) {
points.append( pt1 );
points.append( pt2 );
}
delete circle1;
delete circle2;
return es;
}
static Acad::ErrorStatus intLine( Custom* custom, 
const AcDbLine* line,
AcDb::Intersect intType,
const AcGePlane* projPlane,
AcGePoint3dArray& points) {
Acad::ErrorStatus es = Acad::eOk;
AcGeLineSeg3d lnsg(line->startPoint(), line->endPoint());
es = intLine(custom, lnsg, points);
return es;
}

Acad::ErrorStatus Custom::intersectWith( const AcDbEntity* ent,
AcDb::Intersect intType,
AcGePoint3dArray& points,
int /*thisGsMarker*/,
int /*otherGsMarker*/) const {
assertReadEnabled();
Acad::ErrorStatus es = Acad::eNotImplementedYet;
if (ent == NULL) {
return Acad::eNullEntityPointer;
}
if (ent->isKindOf(AcDbLine::desc())) {
if ((es = intLine((class Custom *const)this, AcDbLine::cast(ent),
intType, NULL, points)) != Acad::eOk) {
return es;
}
} /* else 
if (ent->isKindOf(AcDbArc::desc())) {
if ((es = intArc(this, AcDbArc::cast(ent), intType,
NULL, points)) != Acad::eOk) {
return es;
}
} else 
if (ent->isKindOf(AcDbCircle::desc())) {
if ((es = intCircle(this, AcDbCircle::cast(ent),
intType, NULL, points)) != Acad::eOk) {
return es;
}
} */
return es;
}