I'm trying to make a mod that renders entity health bars in an external window (same width and height as the game window), not the main game window.
To do this, I need to convert an entity's position (x, y, z) to 2D screen coordinates (x, y) so I can render the health bar on the external window.
The external window does not use LWJGL so I cannot use any LWJGL commands to render the health bar.
How would I go about doing this? I tried the method used here, however the 2D coordinates were very incorrect.