Finding the World Space Coordinates of the Screen Edges

Hi - Does anyone know of a way to figure out the world space position of the screen edges, ie top and left, which does not invoke ScreenToWorldPoint()?

Why not ScreenToWorldPoint() ?

Ah, this is where it gets weird. The game starts with a blank screen menu with text. Up until the menu is removed (menu task finished), ScreenToWorldPoint() returns an incorrect x position of -2, when it should be -1.28 (the y position is correct in all cases). Once the startmenu is removed then the correct position is returned. I cannot explain this; there seems to be nothing in startmenu that could cause the error.

I am developing in C# (sorry!), and this behaviour can be reproduced in the ‘SamplyGame’ project, which is a Urhosharp example game.

Possible ScreenToWorldPoint bug · Issue #1504 · urho3d/Urho3D · GitHub

Ok, it seems the ScreenToWorld() works ok. The problem is the camera, specifically the projection matrix is altered from the incorrect (square screen) values (M11=2.41, M22=2.41) to the correct value M11=3.87, M22=2.41.
Why the matrix is altered just by closing the ‘menu’ task, is a mystery to me. It is also a mystery as to why the correct values are not there from the get go. Maybe not a mystery to someone else?

A workaround for this was to wait until the camera projection is correct, then build the scene using ScreenToWorld(). This works, so I guess there is no point continuing this topic.