[PyOpenGL-Users] gluUnProject() and glReadPixels()

[Ian K. <Ian...@rm...>]

I am using a glFrustum projection and am trying to convert mouse event (pixel) coordinates to model coordinates.

I am having problems getting the window Z coordinate.

As I understand, the Z coord is the depth buffer value expressed as a GLdouble with a range of 0-1.  0 being the near clip plane, and 1 being the far clip plane.  My model view is a single textured surface in the x-y plane at z = 0 (object coord) - a 2d map.

I have tried to used glReadPixels to get the win Z coord - but I can't get this function to return a GLDouble, hence gluUnProject doesn't like it.

Looking at the glReadPixels manpages there is a glReadPixelsd() - but pyhton doesn't like this too much.

z = glReadPixels(self.GetParent().xclick,300-self.GetParent().yclick, 1, 1, GL_DEPTH_COMPONENT, ???)
            
worldcoord = gluUnProject(self.GetParent().xclick,300-self.GetParent().yclick,z,model,projection,viewport)

I have looked at OpenGLContext briefly - would rather not use if my problem cam be solved without this module, but open to suggestions at this point!

Thanks

Ian