# Transform Xojo Point From Cartesian's Built-In System

Oliver - I think reading through your code will help you more than reading through the posts in this thread right now. There are only 2 return statements in your code, one where it checks for parallel lines, and the other at the end where it returns true. You need to do something with the calculations in between and return false/true based on those.

Also, make sure your code works for vertical lines. Right now you’re going to get infinite slopes. Again, check out the link I posted.

Bill

[quote=159016:@Bill Gookin]Oliver - I think reading through your code will help you more than reading through the posts in this thread right now. There are only 2 return statements in your code, one where it checks for parallel lines, and the other at the end where it returns true. You need to do something with the calculations in between and return false/true based on those.

Also, make sure your code works for vertical lines. Right now you’re going to get infinite slopes. Again, check out the link I posted.

Bill[/quote]
Thanks.

[quote=159016:@Bill Gookin]Oliver - I think reading through your code will help you more than reading through the posts in this thread right now. There are only 2 return statements in your code, one where it checks for parallel lines, and the other at the end where it returns true. You need to do something with the calculations in between and return false/true based on those.

Also, make sure your code works for vertical lines. Right now you’re going to get infinite slopes. Again, check out the link I posted.

Bill[/quote]

[quote=158962:@Will Shank]Here’s a quick demo using Gookins reference for intersects. Drag the endpoints and the lines turn red when intersecting. http://home.comcast.net/~trochoid/dragSect.zip

A possible keyword, what your trying to deal with in the coordinate transform I know of as Y-Up vs Y-Down orientation.

In your code Drawline has it’s coordinates mixed, it’s (x1, y1, x2, y2)

```Sub Drawline(g as graphics, LINE AS LINESHAPE) //G.DRAWLINE LINE.x1, LINE.x2, LINE.PlotY1, LINE.PlotY2 G.DRAWLINE LINE.x1, LINE.PlotY1, LINE.x2, LINE.PlotY2 End Sub```[/quote]
Thanks.