Move hard coded minimap to builtin

[cx384]

Goal of the PR

• It solves a part of Treat built-in hotbar, nametags, minimap, crosshair like Lua HUD elements #9270
  (I will probably soon make a PR to add HUD new elements for the hotbar and crosshair).
• Fixes Temp-disabling player's minimap shouldn't toggle it "completely off" client-side #8431

How does the PR work?

• Currently, there exists a hard coded minimap that is not handled by a Lua HUD element. However, the HUD element type "minimap" already exists.
• This PR moves this minimap into the builtin Lua code, such that it can be accessed and modified with the lua API.
• It behaves similar to the previous minimap, but there are some differences:
  • Automatic resizing with respect to the client window size does not happen automatically anymore. (Maybe it would be good to have such a feature for all hud elements.)
  • The minimap HUD flag does now only change the builtin minimap. (Before this the flag temporary disabled all Lua element minimaps, but you could turn them back on by pressing the minimap key.)
• When Treat built-in hotbar, nametags, minimap, crosshair like Lua HUD elements #9270 gets completely resolved the builtin statusbars.lua HUD code should be generalized, therefore this PR doesn't do it.
• The compatibility to older versions is not completely contained, since multiple builtin minimaps may be shown, but it is not a breaking change, and I don't think it is a big problem.
  It is now backwards compatible in both directions (server/client).

Unittest info

I completely removed testFlagSetters since showMinimap was the only function in the GameUI class which could change a Hud flag. (The flag is now only managed in builtin like healthbar or breathbar)

To do

This PR is Ready for Review

• Fix the automatic resizing, if it is important. This may need a new feature for all HUD elements.
  Automatic resizing is bad since it would be the only builtin element that does this.
  Now it has a fixed size like all other HUD elements. The size is similar to the previous one, only people which use a window height far away from 1080 pixels may notice a difference.
• The minimap HUD flag should probably only enable/disable the builtin minimap like it is the case with the builtin statusbars. (Currently, the flag only partly influence other minimaps, since they can be reactivated by the client.)
• Make minetest.hud_replace_builtin(name, hud_definition) work with the minimap.

How to test

Use this and press the mimimap key:

-- Print HUD elements
minetest.after(2, function()
	local player = minetest.get_player_by_name("singleplayer")
	for id = 0, 10 do
		local hud = player:hud_get(id)
		if hud and hud.type == "minimap" then
			print(dump(hud))
		end
	end
end)

-- A test HUD element that is not builtin
minetest.register_on_joinplayer(function(player)
	player:hud_add({
		hud_elem_type = "minimap",
		position = {x=0, y=0},
		alignment = {x=1, y=1},
		offset = {x=10, y=10},
		size = {x = 100 , y = 100}
	})
end)

-- Change minimap HUD flag every 3 seconds
local timed = 0
minetest.register_globalstep(function(dtime)
	local name = "singleplayer"
	timed = timed + dtime
	if timed > 3 then
		timed = 0
		local player = minetest.get_player_by_name(name)
		if player:hud_get_flags().minimap then
			minetest.chat_send_player(name, "off")
			player:hud_set_flags({minimap = false})
		else
			minetest.chat_send_player(name, "on")
			player:hud_set_flags({minimap = true})
		end
	end
end)

-- Override the builtin minimap (changed positions)
minetest.hud_replace_builtin("minimap", {
	hud_elem_type = "minimap",
	position = {x=0.5, y=0.5},
	alignment = {x=-1, y=1},
	offset = {x=-10, y=10},
	size = {x = 256 , y = 256}
})

(If you are unsure how the HUD flag should behave execute it also on a previous version.)

Maybe also test if the enable_minimap setting still works.

/set enable_minimap true
/set enable_minimap false

[cx384]

It's rebased and ready for review, so it would be nice if someone could review it.

[cx384]

Rebased again.

[cx384]

This PR probably also solves #8431 if it wasn't already solved.

[appgurueu]

Tested, works. I have a few questions, but the code looks fine as-is. Thanks for the PR.

Fix the automatic resizing, if it is important. This may need a new feature for all HUD elements. Automatic resizing is bad since it would be the only builtin element that does this.

I am fine with your rationale for not fixing this. (Additionally, if needed, modders should be able to implement automatic resizing by querying screen size.)

You could also add a feature for screen-size relative size (similar to how images support percentages via negative values).

[cx384]

Thanks for the review and testing.
I will soon make a PR to refactor the builtin HUD code, to generalize builtin/game/statbars.lua, such that it can not only handle statusbars.
Your questions for builtin/game/minimap.lua will probably be resolved when I'm done with this, and moved the minimap and statusbars code into one file.
(I also need this for my other HUD PRs.)

[grorp]

Backwards compatibility is missing in both directions. Both cases must be fixed.

5.8.0 on the client, this PR on the server: minimap shown twice

The compatibility to older versions is not completely contained, since multiple builtin minimaps may be shown, but it is not a breaking change, and I don't think it is a big problem.

Having two mipmaps on top of each other, each with a different size, is ugly enough to be a concern. It's also easy enough to fix by checking the protocol version.

this PR on the client, 5.8.0 on the server: no minimap at all

always shows "Minimap currently disabled by game or mod"

[cx384]

It is now backwards compatible.
I tested it in both directions, so I hope it behaves as intended.

(At first, I thought it wouldn't be a big problem for the builtin minimap to behave incorrectly when using different versions, since it is a rather dispensable feature.)

[grorp]

Regardless of any potential future refactoring, you can reduce code duplication a lot by moving the minimap code to statbars.lua. (And in that case, it would make sense to rename statbars.lua to hud.lua or similar.)

grorp@59b9323

[cx384]

Ok, moved it into statbars.lua for now, and made a PR to refactor the builtin HUD code. #14346

Edit:
I think the Action / change needed label can be removed, since I resolved every complaint.
It would be nice if this PR would get another review such that it can be merged, but maybe it would be better to first handle the refactoring PR.