I know this question may be beneath most people but pls help.
In GDI the y value goes from top to bottom, OpenGL however goes from bottom to top. Also OpenGl’s origin is nicely placed in the centre of its coordinate system unlike GDI which has it in the top left corner. I am mapping my mouse position to the open gl position using gluProject.
My problem is that when i do this i am getting projected coords from the GL scene that are negative in the x and y directions in some cases. This leads me to believe, as GDI cannot have negative x and y that when the projection occurs it maps the x and y of the 3d objects with the assumption that the origin is at the centre of the window.
Can someone please help me to get my mouse position and the projected position to line up? The SetOriginEx function wont work for some reason so i can’t get the origin at the centre. Any ideas (a) why it isn’t working? (b) how to get the GDI system to make the y value increase upwards
Hope that makes sense