Refactor builtin HUD

[cx384]

Goal of the PR

• Refactor the builtin code for HUD elements, such that it can handle other HUD elements besides statusbars.
• It is needed for Move hard coded minimap to builtin #14071 Add crosshair Lua HUD element and replace hardcoded crosshair #14273 Add hotbar Lua HUD element and replace hardcoded hotbar #14321 and potential future elements, for example for the chat or infotext.
• (The statusbars behave the same as in the old version, the only difference is that hud_replace_builtin does not default definition.item anymore, but this is not documented inlua_api.md so it should be fine. However, I can re-add it if someone thinks it is needed.) readded

Does this relate to a goal in the roadmap?

2.2 Internal code refactoring

To do

This PR is Ready for Review.

How to test

• Start devtest, jump into water to test the breathbar, and hurt yourself to test the healthbar.
• Read the code notice the refactoring.
• Test hud_replace_builtin

minetest.hud_replace_builtin("breath", {
	type = "statbar",
	position = {x = 0.5, y = 0.5},
	text = "bubble.png",
	text2 = "bubble_gone.png",
	number = core.PLAYER_MAX_BREATH_DEFAULT * 2,
	item = core.PLAYER_MAX_BREATH_DEFAULT * 2,
	direction = 0,
	size = {x = 24, y = 24},
	offset = {x = 25, y= -(48 + 24 + 16)}
})

• Test flags

minetest.register_chatcommand("hudtoggleflag", {
	description = "Toggles a hud flag.",
	params = "<flag>",
	func = function(name, params)
		local player = minetest.get_player_by_name(name)
		if not player then
			return false, "No player."
		end

		local flags = player:hud_get_flags()
		if flags[params] == nil then
			return false, "Unknown hud flag."
		end

		flags[params] = not flags[params]
		player:hud_set_flags(flags)
		return true, "Flag \"".. params .."\" set to ".. tostring(flags[params]) .. "."
	end
})

/hudtoggleflag breathbar /hudtoggleflag healthbar

• Also test other builtin elements in case new ones get added by other PRs.

[cx384]

Rebased.
This PR now also fixes a warning you get because hud_elem_type has been renamed to type.
I caused this with #14071, because the PR was made before the renaming, and I missed to change it. Sorry about this.

[cx384]

Rebased again.
(The hud_elem_type/type problem, has already been fixed in master now.)

[cx384]

Thanks for reviewing it.
With the refactoring, I didn't want to change any behavior (even if it is not documented in the API).
However, I applied your assert suggestion now, so minetest.hud_replace_builtin behaves a little differently, but I guess this is good.

I also rebased to make sure that it still works, since it is almost 2 months old.

[grorp]

Hey @rollerozxa, can you do a zipgrep for hud_replace_builtin please?

[rollerozxa]

sure, here: https://content.minetest.net/zipgrep/cf8a1325-8075-44f6-a32c-f10e6ad93f83/

[grorp]

(The statusbars behave the same as in the old version, the only difference is that hud_replace_builtin does not default definition.item anymore, but this is not documented inlua_api.md so it should be fine. However, I can re-add it if someone thinks it is needed.)

Looking through the zipgrep kindly provided by rollerozxa, I can see at least one package relying on this default value (https://content.minetest.net/packages/epCode/what_were_you_expecting/). You have to re-add it for backwards compatibility (and it would be good to document and/or deprecate it).

[cx384]

I resolved everything again, and re-added the undocumented elem_def.item behavior.

Also, I fixed the duplicate breatbbar bug.

[grorp]

For reference: cx384#2

[cx384]

For reference: cx384#2

Seams good, merged. Sorry for being a little late.
(Maybe I should have refactored more and not take too many things from the old code.)

[grorp]

This PR looks OK to me now.

@sfan5 since there have been a lot of changes, you might want to have a look at this again.

[sfan5]

@sfan5 since there have been a lot of changes, you might want to have a look at this again.

I trust your judgement.