Make sure when the trees are placed it doesn't interfere with a protected area

[Panquesito7]

Description

A few years back, I remember that I was working on this feature (when the mod was still available on GitLab), but I didn't fully finish it.
It appears the issue is still present. Would be great if this could be worked on (I could help a little bit if wanted).

moretrees/node_defs.lua

Lines 445 to 450 in 393840b

	-- minp, maxp to be checked, relative to sapling pos
	-- minp_relative.y = 1 because sapling pos has been checked
	{x = -3, y = 1, z = -3},
	{x = 3, y = 6, z = 3},
	-- maximum interval of interior volume check
	4)

[fluxionary]

one of the items on my wish-list is a way for mods to register the dimensions of trees in an abstract way. while this request isn't for such a feature, IMO it's a step in the right direction.

[Panquesito7]

I found the correct values for three saplings back when I was working on it. I might re-work this soon using this method unless there's a better way to do so. IIRC, these should be the correct values. There could be some minor issues, though, but here you go. :)

...
-- this code should be on the `on_place` callback of the sapling registration

if treename == "beech" then
	itemstack = default.sapling_on_place(itemstack, placer, pointed_thing,
		"moretrees:" ..treename.. "_sapling",
		-- minp, maxp to be checked, relative to sapling pos
		-- minp_relative.y = 1 because sapling pos has been checked
		{x = -3, y = 1, z = -4},
		{x = 4, y = 9, z = 3},
		-- maximum interval of interior volume check
	4)
elseif treename == "apple_tree" then
	itemstack = default.sapling_on_place(itemstack, placer, pointed_thing,
		"moretrees:" ..treename.. "_sapling",
		-- minp, maxp to be checked, relative to sapling pos
		-- minp_relative.y = 1 because sapling pos has been checked
		{x = -9, y = 1, z = -9},
		{x = 9, y = 9, z = 9},
		-- maximum interval of interior volume check
	4)
elseif treename == "oak" then
	itemstack = default.sapling_on_place(itemstack, placer, pointed_thing,
		"moretrees:" ..treename.. "_sapling",
		-- minp, maxp to be checked, relative to sapling pos
		-- minp_relative.y = 1 because sapling pos has been checked
		{x = -6, y = 1, z = -6},
		{x = 8, y = 16, z = 6},
		-- maximum interval of interior volume check
	4)

[wsor4035]

while i think this can be useful, it should be behind a setting (maybe off by default?) since checking the whole area probably will be expensive/some people might not care for it

[fluxionary]

expensive

if we assume areas mod instead of minetest.is_protected, the check need not be very expensive. https://github.com/minetest-mods/areas/blob/cba647225ce68bb543b8911063b965a1527b3526/api.lua#L58. i know there's other protection mods out there, but areas is common.