Feature: Native Pannini Projection Support

[Iris-Belle]

Which component should be improved?

Rendering

Describe your feature suggestion in more detail

It'd be great if youd have a native option to enable pannini projection in settings for higher FOV values without the terrible rectilinear distortion. even at 100 fov it does wonders.
warp the image before the UI draws so you dont warp the UI.

Issues:

• there are some issues with the current FOV implementation in Source, anything over 179 completely breaks the rendering so itd need resolving first.

• the fov slider in the settings in P2:CE only changes fov_desired when it should set both fov_desired and cl_fov both should match. cl_fov changes the actual fov you see and fov_desired seems to change the zoom fov start i think?

• the drawback with pannini is that you need to render more pixels in the center and the edges can get away with less since its a cylindrical projection

Previews

at FOV 170 you can see the huge difference with pannini, 170 seems the most usable option but humans usually see around 200-220 degrees so its not quite right.

Rectilinear:

Pannini: (Reshade effect injected before UI draw)

Grid to show how Pannini warps the image to fix the distortion from Rectilinear projection