Need help finding if two line segments intersect or not.

[Revan117]

For my java class I was given an assignment to code two line segments and test if they intersect or not. I'm not asking for the code, I'm trying to do that myself, I'm just wanting to figure out the formula for the two line segments. I have read to use cross product or dot product, but I still need help with the math, plz help.

[PotatoWater]

Check to see if the two lines have the same slope, if not then they intersect.

 

Edit: Missed the part where it said line segment, there is a bit more math involved

[Revan117]

Check to see if the two lines have the same slope, if not then they intersect.

 

Edit: Missed the part where it said line segment, there is a bit more math involved

 

Yeah, that's what I saw, it's not as easy as getting the slope line to get the line segment. I need more help on that part

[A Banana :D]

well whats the current plan for your project that you have done or planned out already?

[PotatoWater]

Yeah, that's what I saw, it's not as easy as getting the slope line to get the line segment. I need more help on that part

What input are you meant to be giving the program

[Revan117]

What input are you meant to be giving the program

Intersection 1              no intersection 1

                       

7 8                               5 10

5 12                             5  2

10 10                           2  1     

3 10                             8  7

[MrBucket101]

@Revan117

http://www.geeksforgeeks.org/check-if-two-given-line-segments-intersect/

This seems like a good start.

 

One thing to consider, is it an intersection if one segment touches the other, but does not overlap?

 

[Revan117]

@Revan117

http://www.geeksforgeeks.org/check-if-two-given-line-segments-intersect/

This seems like a good start.

 

One thing to consider, is it an intersection if one segment touches the other, but does not overlap?

 

Thx I will starting reading it, yes i believe that it's still an intersection.

[Ciccioo]

i go for the method that is pretty much like the one described at the beginning of this tutorial: http://ncase.me/sight-and-light/

i don't think that the explaination there is very good though, feel free to ask specific questions