Improve interoperability without player_monoids and pova (#24)

* Import noobdigital87's changes

Co-authored-by: noobdigital87 <noobdigital87@gmail.com>

* Fix hud type; remove useless code; style

---------

Co-authored-by: noobdigital87 <noobdigital87@gmail.com>

.luacheckrc

@@ -8,5 +8,6 @@ read_globals = {
 	"vector", "ItemStack",
 
 	"player_monoids",
+	"pova",
 	"unifieddyes",
 }

README.md

@@ -31,17 +31,3 @@ The hang glider will wear out every time you use it. The hang glider can be repa
 If the `areas` mod is installed, airspace restrictions can be added to areas using the `/area_flak` command.
 
 When using a hang glider in an area with flak enabled, you will get shot down a few seconds after entering the area, this reduces your HP to 1 and destroys your hang glider.
-
-## API
-
-#### Custom "can fly" checks
-
-```lua
-hangglider.add_fly_check(function(name, player)
-	-- `name` is the playername
-	-- `player` is the PlayerRef
-	-- Add your code here
-	-- Must return `true` (can fly) or `false` (can't fly)
-	return true
-end)
-```

init.lua

@@ -1,4 +1,3 @@
-hangglider = {}
 
 hangglider = {
 	translator = minetest.get_translator('hangglider'),
@@ -6,6 +5,7 @@ hangglider = {
 local S = hangglider.translator
 
 local has_player_monoids = minetest.get_modpath("player_monoids")
+local has_pova = minetest.get_modpath("pova")
 local has_areas = minetest.get_modpath("areas")
 
 local enable_hud_overlay = minetest.settings:get_bool("hangglider.enable_hud_overlay", true)
@@ -18,8 +18,10 @@ local flak_warning = S("You have entered restricted airspace!@n"
 	flak_warning_time)
 
 local hanggliding_players = {}
+local physics_overrides = {}
 local hud_overlay_ids = {}
 
+
 if enable_flak then
 	minetest.register_chatcommand("area_flak", {
 		params = S("<ID>"),
@@ -42,54 +44,106 @@ if enable_flak then
 	})
 end
 
-local function set_hud_overlay(player, name, image)
+function hangglider.is_gliding(player)
+	if not player then
+		return false
+	end
+	return hanggliding_players[player:get_player_name()]
+end
+
+local function set_hud_overlay(player, name, show)
 	if not enable_hud_overlay then
 		return
 	end
-	if not hud_overlay_ids[name] then
+	if not hud_overlay_ids[name] and show == true then
 		hud_overlay_ids[name] = player:hud_add({
-			hud_elem_type = "image",
-			text = image,
+			[minetest.features.hud_def_type_field and "type" or "hud_elem_type"] = "image",
+			text = "hangglider_overlay.png",
 			position = {x = 0, y = 0},
 			scale = {x = -100, y = -100},
 			alignment = {x = 1, y = 1},
 			offset = {x = 0, y = 0},
 			z_index = -150
 		})
-	else
-		player:hud_change(hud_overlay_ids[name], "text", image)
+	elseif hud_overlay_ids[name] and show == false then
+		player:hud_remove(hud_overlay_ids[name])
+		hud_overlay_ids[name] = nil
 	end
 end
 
 local function set_physics_overrides(player, overrides)
+	local player_name = player:get_player_name()
 	if has_player_monoids then
 		for name, value in pairs(overrides) do
 			player_monoids[name]:add_change(player, value, "hangglider:glider")
 		end
+	elseif has_pova then
+		pova.add_override(player_name, "hangglider:glider",
+				{jump = 0, speed = overrides.speed, gravity = overrides.gravity})
+		pova.do_override(player)
 	else
-		player:set_physics_override(overrides)
+		local def = player:get_physics_override()
+		if not physics_overrides[player_name] then
+			physics_overrides[player_name] = {
+				physics = {
+					speed = def.speed,
+					jump = def.jump,
+					gravity = def.gravity,
+				},
+				deltas = {speed = 0, jump = 0, gravity = 0},
+			}
+		end
+		-- Compute the new delta to apply (relative to current physics)
+		local delta = {
+			speed = (overrides.speed or def.speed) - def.speed,
+			jump = (overrides.jump or def.jump) - def.jump,
+			gravity = (overrides.gravity or def.gravity) - def.gravity,
+		}
+		-- Track the sum of all deltas for this session.
+		physics_overrides[player_name].deltas.speed = physics_overrides[player_name].deltas.speed + delta.speed
+		physics_overrides[player_name].deltas.jump = physics_overrides[player_name].deltas.jump + delta.jump
+		physics_overrides[player_name].deltas.gravity = physics_overrides[player_name].deltas.gravity + delta.gravity
+		-- Apply new delta on top of current physics
+		player:set_physics_override({
+			speed = def.speed + delta.speed,
+			jump = def.jump + delta.jump,
+			gravity = def.gravity + delta.gravity,
+		})
 	end
 end
 
 local function remove_physics_overrides(player)
+	local player_name = player:get_player_name()
 	if has_player_monoids then
 		for _, name in pairs({"jump", "speed", "gravity"}) do
 			player_monoids[name]:del_change(player, "hangglider:glider")
 		end
+	elseif has_pova then
+		pova.del_override(player_name, "hangglider:glider")
+		pova.do_override(player)
 	else
-		player:set_physics_override({jump = 1, speed = 1, gravity = 1})
+		local def = player:get_physics_override()
+		if physics_overrides[player_name]
+			and physics_overrides[player_name].physics
+			and physics_overrides[player_name].deltas then
+
+			-- Subtract total delta from current values
+			player:set_physics_override({
+				speed = def.speed - physics_overrides[player_name].deltas.speed,
+				jump = def.jump - physics_overrides[player_name].deltas.jump,
+				gravity = def.gravity - physics_overrides[player_name].deltas.gravity,
+			})
+			physics_overrides[player_name] = nil
+		else
+			player:set_physics_override({speed = 1, jump = 1, gravity = 1})
+		end
 	end
 end
 
-local fly_checks = {}
-
-function hangglider.add_fly_check(func)
-	table.insert(fly_checks, func)
-end
-
-local function can_fly_flak(name, pos)
-	-- Area flak check
-	if enable_flak then
+local function can_fly(pos, name)
+	if not enable_flak then
+		return true
+	end
 	local flak = false
 	local owners = {}
 	for _, area in pairs(areas:getAreasAtPos(pos)) do
@@ -101,17 +155,6 @@ local function can_fly_flak(name, pos)
 	if flak and not owners[name] then
 		return false
 	end
-	end
-end
-
-local function can_fly_custom(name, player)
-	-- Custom checks set by other mods
-	for _, func in ipairs(fly_checks) do
-		local ret = func(name, player)
-		if ret == false then
-			return false
-		end
-	end
 	return true
 end
 
@@ -166,7 +209,7 @@ local function hangglider_step(self, dtime)
 					})
 				end
 			end
-			if not can_fly_flak(name, pos) then
+			if not can_fly(pos, name) then
 				if not self.flak_timer then
 					self.flak_timer = 0
 					shoot_flak_sound(pos)
@@ -181,13 +224,10 @@ local function hangglider_step(self, dtime)
 					gliding = false
 				end
 			end
-			if not can_fly_custom(name, player) then
-				gliding = false
-			end
 			if not gliding then
 				remove_physics_overrides(player)
 				hanggliding_players[name] = nil
-				set_hud_overlay(player, name, "blank.png")
+				set_hud_overlay(player, name, false)
 			end
 		end
 	end
@@ -214,7 +254,7 @@ local function hangglider_use(stack, player)
 					textures = {"wool_white.png^[multiply:#"..color, "default_wood.png"}
 				})
 			end
-			set_hud_overlay(player, name, "hangglider_overlay.png")
+			set_hud_overlay(player, name, true)
 			set_physics_overrides(player, {jump = 0, gravity = 0.25})
 			hanggliding_players[name] = true
 			if hangglider_uses > 0 then
@@ -223,7 +263,7 @@ local function hangglider_use(stack, player)
 			return stack
 		end
 	else
-		set_hud_overlay(player, name, "blank.png")
+		set_hud_overlay(player, name, false)
 		remove_physics_overrides(player)
 		hanggliding_players[name] = nil
 	end
@@ -252,13 +292,15 @@ minetest.register_on_player_hpchange(function(player, hp_change, reason)
 end, true)
 
 minetest.register_entity("hangglider:glider", {
+	initial_properties = {
 		visual = "mesh",
 		visual_size = {x = 12, y = 12},
 		collisionbox = {0,0,0,0,0,0},
 		mesh = "hangglider.obj",
+		textures = {"wool_white.png", "default_wood.png"},
 		immortal = true,
 		static_save = false,
-	textures = {"wool_white.png", "default_wood.png"},
+	},
 	on_step = hangglider_step,
 })
 

mod.conf

@@ -1,5 +1,5 @@
 name = hangglider
 description = Adds a functional hang glider for exploring
 depends = default, wool, dye
-optional_depends = areas, player_monoids, unifieddyes
+optional_depends = areas, player_monoids, pova, unifieddyes
 min_minetest_version = 5.0