Get 45 degree distance

[petermonte]

Hi there,

I'm trying to get the distance between two objects.

Problem is that both objects are -45º rotated but one of them moves up and down with stage resize. So the distance gets a random degree.

I've attached an image so that it could be simpler to understand my problem.

Hope someone could help me.

Regards

PM

[Guest]

As long as both objects are at fixed angles (or known angles) this is not too difficult to figure out. First lets start with what you know: you have two points along two lines. You also have a perpendicular line (the blue line) that contains one of the known points (point A) . Basically the problem is to find point C, which is the point where the blue line intersects line B. Keep in mind, we have the equation to line A, line B and point A so the tangent line (blue line) can be inferred. The math can get a little complex, but that should be enough to get you started. Just search for "intersection line formula" or similar. Here is one page which appeasrs useful:

http://local.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/

[petermonte]

Hi AHernandezIP,

Thanks for the quick reply.

It’s kind of difficult for me to understand entirely the concept you defined but I’m giving it a shot.
If I understood you correctly I can use the advantage of having points A and B. So with point A create a 45º third point (A.x+500, B.x+500) that would create me a new line between A and A2. With point B create two points - B2 and B3. B2 and B3 will be 45º points with a distance of 500px from point B. Point B2 will be in the Top-Right direction (B.x+500, B.y-500) and point B3 in the Bottom-Left direction (B.x-500, B.y+500). This will create a new line between B2 and B3. With these two lines (A-A2, B2-B3) I can calculate the intersection (I found this AS3 LineIntersectionLine function build by Keith Hair) and therefore get missing point C. What I don’t understand is if this intersection point is already the distance I want or I still need to calculate the hypotenuse equation based on points A, B and C and get the A-C segment distance.

Take a look at the attached figure.

Hope you could help me

Regards
PM

[petermonte]

Yep, works perfectly . Thanks AHernandezIP. And also thanks to Keith Hair.