server-nalc/mods/item_drop/init.lua

local enable_damage = minetest.setting_getbool("enable_damage")
local creative_mode = minetest.setting_getbool("creative_mode")

-- Following edits by gravgun
-- Idea is to have a radius pickup range around the player, whatever the height
-- We need to have a radius that will at least contain 1 node distance at the player's feet
-- Using simple trigonometry, we get that we need a radius of
--  sqrt(pickup_range² + player_half_height²)
local pickup_range = 1.3
local pickup_range_squared = pickup_range*pickup_range
local player_half_height = 0.9
local scan_range = math.sqrt(player_half_height*player_half_height + pickup_range_squared)
-- Node drops are insta-pickup, everything else (player drops) are not
local delay_before_playerdrop_pickup = 1.5
-- Time in which the node comes to the player
local pickup_duration = 0.2
-- Little treshold so the items aren't already on the player's middle
local pickup_inv_duration = 1/pickup_duration-0.2

minetest.register_globalstep(function(dtime)
	local tstamp = minetest.get_us_time()
	for _,player in ipairs(minetest.get_connected_players()) do
		if player:get_hp() > 0 or not enable_damage then
			local pos = player:getpos()
			pos.y = pos.y + 0.9
			local inv = player:get_inventory()

			for _,object in ipairs(minetest.get_objects_inside_radius(pos, scan_range)) do
				local luaEnt = object:get_luaentity()
				if not object:is_player() and luaEnt and luaEnt.name == "__builtin:item" then
					local ticky = luaEnt.item_drop_min_tstamp
					if ticky then
						if tstamp >= ticky then
							luaEnt.item_drop_min_tstamp = nil
						end
					elseif not luaEnt.item_drop_nopickup then
						-- Point-line distance computation, heavily simplified since the wanted line,
						-- being the player, is completely upright (no variation on X or Z)
						local pos2 = object:getpos()
						-- No sqrt, avoid useless computation
						-- (just take the radius, compare it to the square of what you want)
						-- Pos order doesn't really matter, we're squaring the result
						-- (but don't change it, we use the cached values afterwards)
						local dX = pos.x-pos2.x
						local dZ = pos.z-pos2.z
						local playerDistance = dX*dX+dZ*dZ
						if playerDistance <= pickup_range_squared then
							local itemStack = ItemStack(luaEnt.itemstring)
							if inv and inv:room_for_item("main", itemStack) then
								local pos1 = pos
								pos1.y = pos1.y-player_half_height+0.5
								local vec = {x=dX, y=pos1.y-pos2.y, z=dZ}
								vec.x = vec.x*pickup_inv_duration
								vec.y = vec.y*pickup_inv_duration
								vec.z = vec.z*pickup_inv_duration
								object:setvelocity(vec)
								luaEnt.physical_state = false
								luaEnt.object:set_properties({
									physical = false
								})
								-- Mark the object as already picking up
								luaEnt.item_drop_nopickup = true

								minetest.after(pickup_duration, function(args)
									local lua = luaEnt
									if object == nil or lua == nil or lua.itemstring == nil then
										return
									end
									if inv:room_for_item("main", itemStack) then
										inv:add_item("main", itemStack)
										if luaEnt.itemstring ~= "" then
											minetest.sound_play("item_drop_pickup", {pos = pos, gain = 0.3, max_hear_distance = 8})
										end
										luaEnt.itemstring = ""
										object:remove()
									else
										object:setvelocity({x = 0,y = 0,z = 0})
										luaEnt.physical_state = true
										luaEnt.object:set_properties({
											physical = true
										})
										luaEnt.item_drop_nopickup = nil
									end
								end, {player, object})
							end
						end
					end
				end
			end
		end
	end
end)

function minetest.handle_node_drops(pos, drops, digger)
	local inv
	if creative_mode and digger and digger:is_player() then
		inv = digger:get_inventory()
	end
	for _,item in ipairs(drops) do
		local count, name
		if type(item) == "string" then
			count = 1
			name = item
		else
			count = item:get_count()
			name = item:get_name()
		end
		if not inv or not inv:contains_item("main", ItemStack(name)) then
			for i=1,count do
				local obj
				local x = math.random(1, 5)
				if math.random(1,2) == 1 then x = -x end

				local z = math.random(1, 5)
				if math.random(1,2) == 1 then z = -z end

				obj = minetest.spawn_item(pos, name)
				if obj ~= nil then
					obj:setvelocity({x=1/x, y=obj:getvelocity().y, z=1/z})
				end
			end
		end
	end
end

local mt_item_drop = minetest.item_drop
function minetest.item_drop(itemstack, dropper, pos)
	if dropper.is_player then
		local v = dropper:get_look_dir()
		local p = {x=pos.x, y=pos.y+1.2, z=pos.z}
		local cs = itemstack:get_count()
		if dropper:get_player_control().sneak then
			cs = 1
		end
		local item = itemstack:take_item(cs)
		local obj = core.add_item(p, item)
		if obj then
			v.x = v.x*2
			v.y = v.y*2 + 2
			v.z = v.z*2
			obj:setvelocity(v)
			obj:get_luaentity().item_drop_min_tstamp = minetest.get_us_time() + delay_before_playerdrop_pickup * 1000000
		end
	else
		core.add_item(pos, itemstack)
	end
	return itemstack
end

if minetest.setting_getbool("log_mods") then
	minetest.log("action", "[item_drop] item_drop overriden: " .. tostring(mt_item_drop) .. " " .. tostring(minetest.item_drop))
	minetest.log("action", "[item_drop] loaded.")
end