kicad-developers team mailing list archive

["Reece R. Pollack" <reece@xxxxxxx>]

On 6/22/19 3:09 AM, Greg Smith wrote:
> Adding two points and dividing by two results in a point that is 
> minimally equidistant from both points (I.e. The midpoint of the line 
> formed by the points).

While it is true that you can add two point coordinates and multiply by 
scalar 0.5 to get the midpoint, this is not true in the general case for 
arbitrary scalar multipliers. However, calculating the vector distance 
between two points, multiplying the vector by a scalar, then adding the 
resulting vector distance to the first point /does/ work in the general 
case.

This is exactly the sort of bug that can be avoided by not allowing 
arbitrary operations on random vectors.

If finding the midpoint between two points proves to be a common 
operation, and is found to be too costly to implement in the general 
fashion, then a special method for determining the midpoint can be 
provided that calculates it in the optimal fashion.