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Gunde

Getting the coordinates after transforming

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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

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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.

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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.

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