Shape/ line plotter thing...

[leezer3]

I'm sure this is out there, but I just can't think of the right search term
I'm looking for a program that will allow me to plot a line from two points in basic X,Y cordinates. If I then say I want to go another 1m further along the line, it then gives me the new cordinate at the end of the line.

Doing my head in, & I'm no good at maths but someone must have thought of it.

-Leezer-

 

[namnoc]

Two points A and B with coordinates (AX, AY) and (BX, BY)

With starting point A:

Gradient = (BY - AY) / (BX - AX)
and angle of line = inverse tan( Gradient)

Increase in X when going beyond B a distance d = d x cos angle
Increase in Y when going beyond B a distance d = d x sin angle

 

[leezer3]

That's what I call headache inducing
I've run it up in C# mind, and it appears to produce the expected results. For anyone nosy:
http://www.bvecornwall.co.uk/downloads/external/mathwhatsit.zip

Please excuse the bad code, but it does the job!

-Leezer-