UI scale breaks start menu

[Robyt3]

With UI scale below 100:

• the aspect ratio of the images is incorrect
• buttons move further down
• size of buttons increases

With UI scale above 100:

• text overlaps images
• buttons move further up
• size of buttons decreases

I'm don't think it's a good idea to apply the UI scale in every V/HSplit. This requires a bunch of fixes like / UI()->Scale() to split elements scale independent again.

Relevant TODO:

ddnet/src/game/client/ui.h

Lines 11 to 15 in 68b6027

	class CUIRect
	{
	// TODO: Refactor: Redo UI scaling
	float Scale() const;

Screenshots:

• ui_scale 50:
  
• ui_scale 70:
  
• ui_scale 100:
  
• ui_scale 110:
  
• ui_scale 120:
  
• ui_scale 150:
  

[def-]

Does it work elsewhere? Maybe we should just remove ui_scale, I'm not sure if it's used much.

[Robyt3]

Values in the range 90-110 mostly seem to work. With other values there are various major/minor issues. Especially the settings are not useable with scale > 110.

[Chairn]

Visually impaired people might use it, but i believe they rely more on OS tools for this.

[def-]

Visually impaired people will have a lot of trouble playing DDNet I think. And OS tools can't interact with our UI at all to get texts out.

[Robyt3]

See also https://github.com/ddnet/ddnet/discussions/4214

[kaitlynia]

The idea to remove ui_scale is a threat to user accessibility. There are many things we could do in order to rework ui_scale:

• Set constraints on how much a given component can shrink/grow
• Make sure lists/grids like the skins list account for ui_scale when the dimensions are calculated, instead of clipping the container
• Implement some positioning system that works more like a web browser, pushing content that won't fit on the current row to the next line and scrolling if the height overflows the container

[heinrich5991]

The idea to remove ui_scale is a threat to user accessibility. There are many things we could do in order to rework ui_scale:

Is there anyone using ui_scale? If yes, we should talk to them. If not, the removal seems fine.

[def-]

It's been broken/untested for many years, so I doubt it has many users.