Thread: I'm lost with mouse motion OpenGL

How are you applying xangle and yangle here?

I'm presuming you can already use the mouse to, eg, move the view or a specific object.

If you want to be able to click on a specific object and do something (I've never tried this) I think you are in for a bit of a challenge: you will have to figure out how to translate screen coordinates into 3D world coordinates.

Not to sure where to start with that. I'm sure if you post to the "official forum"

OpenGL coding: beginners - OpenGL.org Discussion and Help Forums

someone else HAS done this before . I always use the relative change of the mouse position to affect coordinates, which I think is what you are trying to do here.

In the meantime, one obvious thing you could do is throw a printf in (or use the debugger) to track the mouse x/y coords and figure out where the teapot is. A bit hackish since it won't help if you move things around, but it may provide some clues as to the real solution, which I guess must involve the "frustrum" (apt name) or something.

If all you are looking to do is rotate the view around with the mouse, I can show you how to do that. It involves working out a ratio of how far you want to move, eg.

Code:

View.x += ((float)X - (float)MouseX )/4;

Here "X" is the current position and "MouseX" was the previous position in the glut mouse move callback (ie, X was one of the parameters supplied by glut). A bigger denominator will give you greater precision, but less range back and forth, since the mouse pointer cannot go outside the bounds of the window. This is also totally dependent on how you have set up the perspective; I always use a glViewport with the height and width set the same as the window dimensions in pixels.