I have a 2D unit vector containing a world coordinate (the player's direction), and I want to convert that to screen coordinates (classic isometric tiles).
I'm aware I can achieve this by rotating around the relevant axis but I want to see and understand how to do this using a purely matrix approach? Partly because I'm learning 'modern OpenGL' (v2+) and partly because I will want to use this same technique for other things so need a solid understanding and my math ability is a little lacking.
If needed my screen's coordinate system has it's origin at top left with +x & +y pointing right and down respectively. Also, my vertex positions are converted to the NDC range in my vertex shader if that's relevant.
Language is C++ with no supporting libraries.