[ZH] Adjust field of view based on aspect ratio

[valeronm]

The game doesn't support wide screens well because it has static horizontal field of view (FOV) and static maximum camera height. This means that for every resolution, the camera shows the same horizontal amount of terrain, but the vertical field of view becomes narrower for wider resolutions. So on wide screens, we get a center crop of what is visible on 4:3 resolutions (screenshots below).
To support wider screens, we need to have constant vertical FOV and calculate horizontal FOV based on the screen aspect ratio.

Changes

• Added function W3DView::adjustFovToAspectRatio which is called every time when display resolution changes;
• Function adjustFovToAspectRatio changes camera FOV differently based on aspect ratio:
  • when screen is wider than 4:3 it sets the fixed vertical FOV based on vFOV used for 4:3 screens (38.55°);
  • when screen narrower than 4:3 but still horizontal, it sets fixed hFOV used for 4:3 screens (50°) - this is what the game always uses now;
  • for portrait screens it uses varying 50° to 60° vFOV

Screenshots

1600 x 1200 - 4:3 (original)

1600 x 900 - 16:9 (original)

1600 x 900 - 16:9 (new logic)

3200 x 900 - 32:9 (new logic)

900 x 1600 - 9:16 (new logic)

Fixes #78
Depends on #460 to make wide resolutions selectable

[ElTioRata]

Can I ask why do you get less horizontal FOV on 9:16 compared to 4:3?

[DevGeniusCode]

Is the PR only for Zero Hour? Because I see changes in Generals too.

[valeronm]

Can I ask why do you get less horizontal FOV on 9:16 compared to 4:3?

This is done on purpose. The same horizontal FOV will allow seeing almost the entire map in portrait mode. I'm sure this is not an ideal fix for portrait modes, but it should be good enough until a better solution is implemented. One possible solution is to change the angle of the camera towards the terrain for portrait screens.

900 x 1600 with fixed hFOV used for 4:3 screens

Is the PR only for Zero Hour? Because I see changes in Generals too.

This PR depends on #460, so the current branch contains one commit from that PR, which includes changes for both Generals and Zero Hour. After merging #460, this PR will have changes for Zero Hour only.

[ElTioRata]

The same horizontal FOV will allow seeing almost the entire map in portrait mode.

Out of curiosity, how does it look on 1:1?

[valeronm]

Out of curiosity, how does it look on 1:1?

I've made the spreadsheet with original and FOV values and also made the folder with screenshots for different aspect ratios.

[OmniBlade]

Can I ask why do you get less horizontal FOV on 9:16 compared to 4:3?

This is done on purpose. The same horizontal FOV will allow seeing almost the entire map in portrait mode. I'm sure this is not an ideal fix for portrait modes, but it should be good enough until a better solution is implemented. One possible solution is to change the angle of the camera towards the terrain for portrait screens.
900 x 1600 with fixed hFOV used for 4:3 screens

If you are playing on your phone maybe you need this :D