GstarCAD's geometry calculator sample

People often don't know about GstarCAD's built in geometry calculator. While it lacks in interface appeal it more than makes up for it in capability. Take the ability to snap to a point between to endpoints. Consider this example where a circle is placed halfway between the endpoints of two lines.

Command: CIRCLE
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 'CAL
>> Expression: MEE
>> Select one endpoint for MEE:
>> Select another endpoint for MEE:

The key is when prompted to specify any point, enter 'CAL and type in the expression.  In the case of MEE it knows you want endpoints and you don't have to use an object snap when picking.  Also bear in mind that MEE is only one of dozens of expressions available in GstarCAD.