Question

Ok so let me try to explain this the best way that i can.

I have two points plotted ‘A’ and ‘B’ and I am trying to plot a third point ‘C’ so that it is past point ‘B’ but along the same slope. I have the angle of the line and I would post some code but I really have no idea where to begin.

any help would be awesome!

Just a little code that i do have

CGPoint vector = ccpSub(touchedPoint, fixedPoint);
CGFloat rotateAngle = -ccpToAngle(vector);

Answer 1

Assuming that by this you mean you need a 3rd point C added such that all the points are colinear, all you need to do is calculate the vector that takes you from A to B, and then generate a new point by adding multiples of this vector to the point B. Choose the multiple based on the distance you want C to be from B.

As an example, say A = (2,2), B = (4,3). Then the vector from A to B is given by (2,1).

All you need to do then is work out how far your new point is from B and add a multiple K*(2,1) to your point B where K is chosen to meet the requirements of your distance

I am assuming you are in 2D, but the same method would apply in higher dimensions