OpenGL / C++

Sup /prog/
I'm currently trying my way around OpenGL. I've drawn a simple Rectangle and I also know how to determine the current mouse position, when the left mouse button is clicked.
Now how can I found out the window coordinates of my rectangle so I can check if the user does a left click inside the rectangle?

>>1
Read SICP.

Now how can I found out the window coordinates of my rectangle
You drew it.

>>3
I mean how do I found out the WINDOW COORDINATES of where I drew it.

glBegin(GL_QUADS);
      glVertex3f(-2.5f, 1.0f, -6.0f);
        glVertex3f(-0.5f, 1.0f, -6.0f);
        glVertex3f(-0.5f, -1.0f, -6.0f);
        glVertex3f(-2.5f, -1.0f, -6.0f);
    glEnd();

This is how I drew it. But I need window coordinates for checking if the user clicks within the rectangle.

>>1
I've never used OpenGl, but wouldn't you need one corner and a size (or two corners) to draw a rectangle? If you can't work out it out from those you have no business programming.

>>4
If you're doing 2d, you can adjust the scale to work in window pixels. Otherwise, do some math.

>>5
>>6

Yeah just found out I can do it via gluProject. Just need to find a way to generalize the function call so that it works on any given rectangle (or object for that matter). Thanks though.