Add medkits, remove apples

mods/pvp/medkits/init.lua

@@ -0,0 +1,121 @@
+-- Table of tables indexed by player names, each having three fields:
+-- * HP at time of left-click + regen_max,
+-- * Max HP of player (generally 20)
+-- * ID of "healing effect" HUD element
+local players = {}
+
+local regen_max = 6        -- Max HP provided by one medkit
+local regen_interval = 0.5 -- Time in seconds between each iteration
+local regen_timer = 0      -- Timer to keep track of regen_interval
+local regen_step = 1       -- Number of HP added every iteration
+
+-- Boolean function for use by other mods to check if a player is healing
+function is_healing(name)
+	return players[name] and true or false
+end
+
+-- Called when player uses a medkit
+-- Aborts if player is already healing
+local function start_healing(stack, player)
+	if not player then
+		return stack
+	end
+	local name = player:get_player_name()
+
+	if players[name] or player:get_hp() >= 20 then
+		return stack
+	end
+
+	players[name] = {
+		pos    = player:get_pos(),
+		target = player:get_hp() + regen_max,
+		hud    = player:hud_add({
+			hud_elem_type = "image",
+			position = {x = 0.5, y = 0.5},
+			scale = {x = -100, y = -100},
+			text = "medkit_hud.png"
+		})
+	}
+
+	stack:take_item()
+	return stack
+end
+
+-- Called after regen is complete. Remove additional effects
+-- If interrupted == true, revert to original HP and give back one medkit.
+local function stop_healing(player, interrupted)
+	local name = player:get_player_name()
+	local info = players[name]
+
+	players[name] = nil
+	if interrupted then
+		minetest.chat_send_player(name, minetest.colorize("#FF4444",
+										"Your healing was interrupted!"))
+		player:set_hp(info.target - regen_max)
+		player:get_inventory():add_item("main", ItemStack("medkits:medkit 1"))
+	end
+
+	player:hud_remove(info.hud)
+end
+
+-- Called after left-click every n seconds (determined by regen_interval)
+-- heals player for a total of regen_max, limited by player's max hp
+minetest.register_globalstep(function(dtime)
+	regen_timer = regen_timer + dtime
+	if regen_timer < regen_interval then
+		return
+	end
+
+	for name, info in pairs(players) do
+		local player = minetest.get_player_by_name(name)
+		if not player then
+			players[name] = nil
+		else
+			-- Abort if player moves more than 1m in any direction to
+			-- allow players to manually interrupt healing if necessary
+			local pos = player:get_pos()
+			if vector.distance(pos, info.pos) >= 1 then
+				stop_healing(player, true)
+			end
+
+			-- Stop healing if target reached
+			local hp = player:get_hp()
+			if hp < info.target and hp < 20 then
+				player:set_hp(hp + regen_step)
+			else
+				stop_healing(player)
+			end
+		end
+	end
+	regen_timer = 0
+end)
+
+-- If player takes damage while healing,
+-- stop regen and revert back to original state
+minetest.register_on_player_hpchange(function(player, hp, reason)
+	if hp < 0 then
+		if players[player:get_player_name()] then
+			stop_healing(player, true)
+		end
+		if reason and reason.type == "punch" then
+			local hitter = reason.object
+			if hitter and players[hitter:get_player_name()] then
+				stop_healing(hitter, true)
+			end
+		end
+	end
+	return hp
+end, true)
+
+minetest.register_on_leaveplayer(function(player)
+	players[player:get_player_name()] = nil
+end)
+
+minetest.register_craftitem("medkits:medkit", {
+	description = "Medkit",
+	inventory_image = "medkit_medkit.png",
+	wield_image = "medkit_medkit.png",
+	stack_max = 10,
+
+	on_use = start_healing
+})