ACAD 2013 - ObjectARX C++ - point line intersection

[gatti.massimo]

Hi,

I have to understand if a point is on a line.

What methods could I use?

I tried intersectwith(..)

but I can't read the acgepoint3darray...

Is there a simple method on acdbline to check this condition? for example with projections?

Thank you for your time.

Best regards

[loic.jourdan · Accepted solution]

Hi,

You can try

 - AcDbCurve::getParamAtPoint which returns an invalid error status if the input point is not on the curve.

 - AcDbCurve::getClosestPointTo and test if result point equals the input one

not sure which is the best, I guess the first one.

[Nick1983]

AcDbCurve::getClosestPointTo
if your "givenPnt.isEqualTo(pointOnCurve)" after function usage point is on line )))

[owenwengerd]

The answer depends on what exactly you mean by "on a line". Since you mention projections, I wonder if you're trying to determine whether a projection of a point intersects a line.

[gatti.massimo]

Thanks,

for your answers.

"On a line", for me, means the point satisfy the equations which define the line and is between startpoint and endpoint.