Hi!!! I''m making a simple 2D drawing editor in OpenGl. I wonder how to get the coordinates of a vertex after transforming it. Here is an example of what I mean. Ex. .. glBegin(LINE_STRIPE); glVertex2d(10.0, 10.0); glVertex2d(100.0, 100.0); glEnd(); glRotate3f(13.4, 0.0, 0.0); /* After I have rotated, what are the new vertex coordinates. I need to find out this, because I want to be able to select this object.*/ All help is good help... /Gunde

Forgive me if I''m wrong, but don''t you have to transform BEFORE you call glVertex?

And I think all you need to do is run your vertices manually through the matrices.

Yes, you have to do any transforms before you draw, otherwise whatever you draw wont be transformed.

You can use glGetFloatv() to return the transformed coordnates to a matrix.