Various adjustments and fixes

lib/player_physics.lua

@@ -0,0 +1,88 @@
+local mod_player_monoids = minetest.get_modpath("player_monoids") ~= nil
+local mod_playerphysics = minetest.get_modpath("playerphysics") ~= nil
+local mod_pova = minetest.get_modpath("pova") ~= nil
+
+local physics = {}
+
+-- use player monoids if available
+if mod_player_monoids then
+	function physics.add(id, player, effect, value)
+		player_monoids[effect]:add_change(player, value, id)
+	end
+
+	function physics.remove(id, player, effect)
+		player_monoids[effect]:del_change(player, id)
+	end
+
+-- fallback to playerphysics if available
+elseif mod_playerphysics then
+	function physics.add(id, player, effect, value)
+		playerphysics.add_physics_factor(player, effect, id, value)
+	end
+
+	function physics.remove(id, player, effect)
+		playerphysics.remove_physics_factor(player, effect, id)
+	end
+
+-- fallback to pova if available
+-- pova uses additive effect modifiers
+-- this tries to simulate multiplication
+-- by including the default value in modifier calculation
+elseif mod_pova then
+	function physics.add(id, player, effect, value)
+		local playername = player:get_player_name()
+		local defaults = pova.get_override(playername, "default")
+		local default
+		if defaults == nil or defaults[effect] == nil then default = 1
+		else default = defaults[effect] end
+		local override = {}
+		override[effect] = (value * default) - default
+		pova.add_override(playername, id, override)
+		pova.do_override(playername)
+	end
+
+	function physics.remove(id, player, effect)
+		local playername = player:get_player_name()
+		pova.del_override(playername, id)
+		pova.do_override(playername)
+	end
+
+-- fallback to vanilla override as last resort
+else
+	local physics = {}
+	local function apply_physics(player)
+		local playername = player:get_player_name()
+		local override = { speed = 1, jump = 1, gravity = 1 }
+		for effect, modifiers in pairs(physics[playername]) do
+			override[effect] = 1
+			for _, modifier in pairs(modifiers) do
+				override[effect] = override[effect] * modifier
+			end
+		end
+		player:set_physics_override(override)
+	end
+
+	function physics.add(id, player, effect, value)
+		local playername = player:get_player_name()
+		if physics[playername] == nil then physics[playername] = {} end
+		if physics[playername][effect] == nil then physics[playername][effect] = {} end
+		physics[playername][effect][id] = value
+		apply_physics(player)
+	end
+
+	function physics.remove(id, player, effect)
+		local playername = player:get_player_name()
+		if physics[playername] == nil then return end
+		if physics[playername][effect] == nil then return end
+		if physics[playername][effect][id] == nil then return end
+		physics[playername][effect][id] = nil
+		apply_physics(player)
+	end
+
+	minetest.register_on_leaveplayer(function(player)
+		local playername = player:get_player_name()
+		physics[playername] = nil
+	end)
+end
+
+return physics