dfcaverns/trees/blood_thorn.lua

--------------------------------------------------
-- Blood thorn

-- Max trunk height 	5
-- red with purple mottling
-- High density wood
-- Depth 3

-- internationalization boilerplate
local MP = minetest.get_modpath(minetest.get_current_modname())
local S, NS = dofile(MP.."/intllib.lua")

minetest.register_node("dfcaverns:blood_thorn", {
	description = S("Blood Thorn Trunk"),
	tiles = {"dfcaverns_blood_thorn_top.png", "dfcaverns_blood_thorn_top.png",
		"dfcaverns_blood_thorn_side.png", "dfcaverns_blood_thorn_side.png", "dfcaverns_blood_thorn_side.png", "dfcaverns_blood_thorn_side.png"},
	paramtype2 = "facedir",
	paramtype = "light",
	groups = {choppy = 3, flammable = 2, light_sensitive_fungus = 11},
	_dfcaverns_dead_node = "dfcaverns:blood_thorn_dead",
	sounds = default.node_sound_wood_defaults(),
	on_place = minetest.rotate_node,
})

minetest.register_node("dfcaverns:blood_thorn_dead", {
	description = S("Dead Blood Thorn Trunk"),
	tiles = {"dfcaverns_blood_thorn_top.png^[multiply:#804000", "dfcaverns_blood_thorn_top.png^[multiply:#804000",
		"dfcaverns_blood_thorn_side.png^[multiply:#804000"},
	paramtype2 = "facedir",
	groups = {choppy = 3, flammable = 2},
	sounds = default.node_sound_wood_defaults(),
	on_place = minetest.rotate_node,
})

minetest.register_node("dfcaverns:blood_thorn_spike", {
	description = S("Blood Thorn Spike"),
	tiles = {
		"dfcaverns_blood_thorn_spike_side.png^[transformR90",
		"dfcaverns_blood_thorn_spike_side.png^[transformR270",
		"dfcaverns_blood_thorn_spike_side.png",
		"dfcaverns_blood_thorn_spike_side.png^[transformR180",
		"dfcaverns_blood_thorn_spike_front.png",
		"dfcaverns_blood_thorn_spike_front.png"
		},
	groups = {choppy = 3, flammable = 2, fall_damage_add_percent=100, light_sensitive_fungus = 11},
	_dfcaverns_dead_node = "dfcaverns:blood_thorn_spike_dead",
	sounds = default.node_sound_wood_defaults(),
	drawtype = "nodebox",
	climbable = true,
	damage_per_second = 1,
	paramtype = "light",
	paramtype2 = "facedir",
	node_box = {
		type = "fixed",
		fixed = {
			{-0.1875, -0.1875, 0.1875, 0.1875, 0.1875, 0.5}, -- base
			{-0.125, -0.125, -0.125, 0.125, 0.125, 0.1875}, -- mid
			{-0.0625, -0.0625, -0.5, 0.0625, 0.0625, -0.125}, -- tip
		}
	},
})

minetest.register_node("dfcaverns:blood_thorn_spike_dead", {
	description = S("Dead Blood Thorn Spike"),
	tiles = {
		"dfcaverns_blood_thorn_spike_side.png^[transformR90^[multiply:#804000",
		"dfcaverns_blood_thorn_spike_side.png^[transformR270^[multiply:#804000",
		"dfcaverns_blood_thorn_spike_side.png^[multiply:#804000",
		"dfcaverns_blood_thorn_spike_side.png^[transformR180^[multiply:#804000",
		"dfcaverns_blood_thorn_spike_front.png^[multiply:#804000",
		"dfcaverns_blood_thorn_spike_front.png^[multiply:#804000"
		},
	groups = {choppy = 3, flammable = 2, fall_damage_add_percent=100},
	sounds = default.node_sound_wood_defaults(),
	drawtype = "nodebox",
	climbable = true,
	paramtype = "light",
	paramtype2 = "facedir",
	node_box = {
		type = "fixed",
		fixed = {
			{-0.1875, -0.1875, 0.1875, 0.1875, 0.1875, 0.5}, -- base
			{-0.125, -0.125, -0.125, 0.125, 0.125, 0.1875}, -- mid
			{-0.0625, -0.0625, -0.5, 0.0625, 0.0625, -0.125}, -- tip
		}
	},
})

local spike_directions = {
	{dir={x=0,y=0,z=1}, facedir=2},
	{dir={x=0,y=0,z=-1}, facedir=0},
	{dir={x=1,y=0,z=0}, facedir=3},
	{dir={x=-1,y=0,z=0}, facedir=1}
}

-- This ensures consistent random maximum to bloodthorn growth
local max_bloodthorn_height = function(pos)
	local next_seed = math.random(1, 1000000000)
	math.randomseed(pos.x + pos.z * 2 ^ 8)
	local output = math.random(3,6)
	math.randomseed(next_seed)
	return output
end

function dfcaverns.grow_blood_thorn(pos, node)
	if node.param2 >= 4 then
		return
	end
	pos.y = pos.y - 1
	if minetest.get_item_group(minetest.get_node(pos).name, "sand") == 0 then
		return
	end
	pos.y = pos.y + 1
	local height = 0
	local max_height = max_bloodthorn_height(pos)
	while node.name == "dfcaverns:blood_thorn" and height < max_height do
		height = height + 1
		pos.y = pos.y + 1
		node = minetest.get_node(pos)
	end
	if height == 7 or node.name ~= "air" then
		return
	end

	minetest.set_node(pos, {name = "dfcaverns:blood_thorn"})
	
	local dir = spike_directions[math.random(1,4)]
	local spike_pos = vector.add(pos, dir.dir)
	if minetest.get_node(spike_pos).name == "air" then
		minetest.set_node(spike_pos, {name="dfcaverns:blood_thorn_spike", param2=dir.facedir})
	end
	dir = spike_directions[math.random(1,4)]
	spike_pos = vector.add(pos, dir.dir)
	if minetest.get_node(spike_pos).name == "air" then
		minetest.set_node(spike_pos, {name="dfcaverns:blood_thorn_spike", param2=dir.facedir})
	end
	return true
end

minetest.register_abm({
	label = "Grow Blood Thorn",
	nodenames = {"dfcaverns:blood_thorn"},
	catch_up = true,
	interval = dfcaverns.config.blood_thorn_growth_interval,
	chance = dfcaverns.config.blood_thorn_growth_chance,
	action = function(pos, node)
		dfcaverns.grow_blood_thorn(pos, node)
	end
})

function dfcaverns.spawn_blood_thorn(pos)
	local height = max_bloodthorn_height(pos)
	local x, y, z = pos.x, pos.y, pos.z
	local maxy = y + height -- Trunk top

	local vm = minetest.get_voxel_manip()
	local minp, maxp = vm:read_from_map(
		{x = x - 1, y = y, z = z - 1},
		{x = x + 1, y = maxy, z = z + 1}
	)
	local area = VoxelArea:new({MinEdge = minp, MaxEdge = maxp})
	local data = vm:get_data()
	local data_param2 = vm:get_param2_data()

	dfcaverns.spawn_blood_thorn_vm(area:indexp(pos), area, data, data_param2, height)

	vm:set_data(data)
	vm:set_param2_data(data_param2)
	vm:write_to_map()
	vm:update_map()
end

local c_air = minetest.get_content_id("air")
local c_ignore = minetest.get_content_id("ignore")
local c_blood_thorn = minetest.get_content_id("dfcaverns:blood_thorn")
local c_blood_thorn_spike = minetest.get_content_id("dfcaverns:blood_thorn_spike")

dfcaverns.spawn_blood_thorn_vm = function(vi, area, data, data_param2, height)
	local pos = area:position(vi)
	if height == nil then height = max_bloodthorn_height(pos) end
	local x = pos.x
	local y = pos.y
	local z = pos.z
	local maxy = y + height -- Trunk top

	for yy = y, maxy do
		local vi = area:index(x, yy, z)
		local node_id = data[vi]
		if node_id == c_air or node_id == c_ignore then
			data[vi] = c_blood_thorn
			
			local dir = spike_directions[math.random(1,4)]
			local spike_pos = {x = pos.x + dir.dir.x, y = yy, z = pos.z + dir.dir.z}
			vi = area:indexp(spike_pos)
			if data[vi] == c_air or data[vi] == c_c_ignore then
				data[vi] = c_blood_thorn_spike
				data_param2[vi] = dir.facedir
			end

			dir = spike_directions[math.random(1,4)]
			spike_pos = {x = pos.x + dir.dir.x, y = yy, z = pos.z + dir.dir.z}
			vi = area:indexp(spike_pos)
			if data[vi] == c_air or data[vi] == c_c_ignore then
				data[vi] = c_blood_thorn_spike
				data_param2[vi] = dir.facedir
			end
		else
			break
		end
	end
end