Unified and refactored FOV API code

Removed a debug statement that was broken.
Changed `modififer` to `modifier` in a code block.

mods/ITEMS/mcl_bows/bow.lua

@@ -33,6 +33,15 @@ local bow_load = {}
 -- Another player table, this one stores the wield index of the bow being charged
 local bow_index = {}
 
+-- define FOV modifier(s)
+mcl_fovapi.register_modifier({
+	name = "bowcomplete",
+	fov_factor = 0.8,
+	time = 1,
+	reset_time = 0.3,
+	is_multiplier = true,
+})
+
 function mcl_bows.shoot_arrow(arrow_item, pos, dir, yaw, shooter, power, damage, is_critical, bow_stack, collectable)
 	local obj = minetest.add_entity({x=pos.x,y=pos.y,z=pos.z}, arrow_item.."_entity")
 	if power == nil then
@@ -183,6 +192,9 @@ end
 
 -- Resets the bow charging state and player speed. To be used when the player is no longer charging the bow
 local function reset_bow_state(player, also_reset_bows)
+	-- clear the FOV change from the player.
+	mcl_fovapi.remove_modifier(player, "bowcomplete") -- for the complete zoom in FOV Modifier.
+
 	bow_load[player:get_player_name()] = nil
 	bow_index[player:get_player_name()] = nil
 	if minetest.get_modpath("playerphysics") then
@@ -314,6 +326,9 @@ controls.register_on_hold(function(player, key, time)
 		end
 		bow_load[name] = minetest.get_us_time()
 		bow_index[name] = player:get_wield_index()
+
+		-- begin Bow Zoom.
+		mcl_fovapi.apply_modifier(player, "bowcomplete")
 	else
 		if player:get_wield_index() == bow_index[name] then
 			if type(bow_load[name]) == "number" then

mods/ITEMS/mcl_bows/mod.conf

@@ -1,6 +1,6 @@
 name = mcl_bows
 author = Arcelmi
 description = This mod adds bows and arrows for MineClone 2.
-depends = controls, mcl_particles, mcl_enchanting, mcl_init, mcl_util, mcl_shields
+depends = controls, mcl_particles, mcl_enchanting, mcl_init, mcl_util, mcl_shields, mcl_fovapi
 optional_depends = awards, mcl_achievements, mcl_core, mcl_mobitems, playerphysics, doc, doc_identifier, mesecons_button
 

mods/ITEMS/mcl_spyglass/init.lua

@@ -17,6 +17,15 @@ minetest.register_craft({
 	}
 })
 
+mcl_fovapi.register_modifier({
+	name = "spyglass",
+	fov_factor = 8,
+	time = 0.1,
+	reset_time = 0,
+	is_multiplier = false,
+	exclusive = true,
+})
+
 local spyglass_scope = {}
 
 local function add_scope(player)
@@ -37,7 +46,8 @@ local function remove_scope(player)
 		player:hud_remove(spyglass_scope[player])
 		spyglass_scope[player] = nil
 		player:hud_set_flags({wielditem = true})
-		player:set_fov(86.1)
+		mcl_fovapi.remove_modifier(player, "spyglass") -- use the api to remove the FOV effect.
+		-- old code: player:set_fov(86.1)
 	end
 end
 
@@ -55,7 +65,8 @@ controls.register_on_hold(function(player, key, time)
 	if key ~= "RMB" then return end
 	local wielditem = player:get_wielded_item()
 	if wielditem:get_name() == "mcl_spyglass:spyglass" then
-		player:set_fov(8, false, 0.1)
+		mcl_fovapi.apply_modifier(player, "spyglass") -- apply the FOV effect.
+		-- old code: player:set_fov(8, false, 0.1)
 		if spyglass_scope[player] == nil then
 			add_scope(player)
 		end

mods/ITEMS/mcl_spyglass/mod.conf

@@ -1,4 +1,4 @@
 name = mcl_spyglass
 author = NO11
 description = This mod adds a spyglass, which is an item that can be used for zooming in on specific locations.
-depends = mcl_core, controls
+depends = mcl_core, controls, mcl_fovapi

mods/PLAYER/mcl_fovapi/api.md

@@ -0,0 +1,82 @@
+### FOV API
+
+<!-- TOC -->
+* [FOV API](#fov-api)
+    * [Description](#description)
+    * [Troubleshooting](#troubleshooting)
+    * [Modifier Definition](#modifier-definition-)
+    * [Global MCL_FOVAPI Tables](#global-mclfovapi-tables)
+    * [Namespaces](#namespaces)
+    * [Functions](#functions)
+<!-- TOC -->
+
+#### Description
+This API defines and applies different Field Of View effects to players via MODIFIERS.
+
+#### Troubleshooting
+In the `init.lua` file for this module, there is a `DEBUG` variable at the top that will turn on logging. 
+Use it to see what is going on.
+
+#### Modifier Definition 
+```lua 
+def = {
+    name = name,
+    fov_factor = fov_factor,
+    time = time,
+    reset_time = reset_time,
+    is_multiplier = is_multiplier,
+    exclusive = exclusive,
+    on_start = on_start,
+    on_end = on_end,
+}
+```
+* Name: The name of the Modifier, used to identify the specific modifier. Case sensitive.
+* FOV Factor: A float value defining the FOV to apply. Can be an absolute or percentage, depending on Exclusive and 
+    Is_Multiplier.
+* Time: A float value defining the number of seconds to take when applying the FOV Factor. 
+    Used to smoothly move between FOVs. Use 0 for an immediate FOV Shift. (Transition time.)
+* Reset Time: A float value defining the number of seconds to take when removing the FOV Factor.
+    Used to smoothly move between FOVs. Use 0 for an immediate FOV Shift. (Reset transition time.)
+    Defaults to `time` if not defined.
+* Is Multiplier: A bool value used to specify if the FOV Factor is an absolute FOV value or if it should be a percentage 
+    of the current FOV. Defaults to `true` if not defined.
+* Exclusive: A bool value used to specify whether the modifier will override all other FOV modifiers. An example of this 
+    is how the spy glass sets the FOV to be a specific value regardless of any other FOV effects applied. Defaults to 
+    `false` if not defined. 
+* On Start: the `on_start` is a callback function `on_start(player)` that is called if defined. The parameter `player` 
+    is a ref to the player that had the modifier applied. Called from `mcl_fovapi.apply_modifier` immediately after 
+    the FOV Modifier has been applied.
+* On End: the `on_end` is a callback function `on_end(player)` that is called if defined. The parameter `player`
+  is a ref to the player that had the modifier applied. Called from `mcl_fovapi.remove_modifier` immediately after
+  the FOV Modifier has been removed.
+
+Note: passing incorrect values in the definition will have unintended consequences.
+
+#### Global MCL_FOVAPI Tables
+There are three tables that are accessible via the API. They are `registered_modifiers` and `applied_modifiers`.  
+
+`mcl_fovapi.registered_modifiers` has the definitions of all the registered FOV Modifiers. Indexed by Modifier Name. 
+And, `mcl_fovapi.applied_modifiers` is indexed by the Player Name. It contains the names of all the modifiers applied to the 
+player.
+
+#### Namespaces
+`mcl_fovapi` is the default API Namespace.
+
+#### Functions
+`mcl_fovapi.register_modifier(def)`
+
+Used to register a new FOV Modifier for use. Must be called before applying said modifier to a player.
+See Modifier Definition for what the parameters are.
+
+`mcl_fovapi.apply_modifier(player, modifier_name)`
+
+Used to apply a registered FOV modifier to a player. Takes a reference to the player and the modifier's name (string).
+
+`mcl_fovapi.remove_modifier(player, modifier_name)`
+
+Used to remove a specific FOV modifier from a Player. Takes a reference to the player and the modifier's name (string).
+Removed immediately.
+
+`mcl_fovapi.remove_all_modifiers(player)`
+
+Used to remove all FOV modifiers from a Player. Takes a reference to the Player. FOV change is instantaneous.

mods/PLAYER/mcl_fovapi/init.lua

@@ -0,0 +1,232 @@
+---
+--- Copyright 2023, Michieal.
+--- License: GPL3. (Default Mineclone2 License)
+--- Created by michieal.
+--- DateTime: 12/2/23 5:47 AM
+---
+
+-- Locals (and cached)
+local DEBUG = false -- debug constant for troubleshooting.
+local pairs = pairs
+
+-- Globals
+mcl_fovapi = {}
+
+mcl_fovapi.registered_modifiers = {}
+mcl_fovapi.applied_modifiers = {}
+
+minetest.register_on_joinplayer(function(player)
+	local player_name = player:get_player_name()
+
+	-- initialization
+	mcl_fovapi.applied_modifiers[player_name] = {}
+end)
+minetest.register_on_leaveplayer(function(player)
+	local player_name = player:get_player_name()
+
+	-- handle clean up
+	mcl_fovapi.applied_modifiers[player_name] = nil
+end)
+
+function mcl_fovapi.register_modifier(def)
+	if type(def.name) ~= "string" then
+		error("Modifier name must be a string")
+	end
+	if type(def.fov_factor) ~= "number" then
+		error("FOV factor must be a number")
+	end
+	if type(def.time) ~= "number" then
+		error("Transition time must be a number")
+	end
+	if def.reset_time ~= nil and type(def.reset_time) ~= "number" then
+		error("Reset time, if provided, must be a number")
+	end
+
+	if def.on_start ~= nil and type(def.on_start) ~= "function" then
+		error("Callback on_start must be a function")
+	end
+	if def.on_end ~= nil and type(def.on_end) ~= "function" then
+		error("Callback on_end must be a function")
+	end
+
+	local mdef = {}
+
+	mdef.fov_factor = def.fov_factor
+	mdef.time = def.time
+	mdef.reset_time = def.reset_time or def.time
+
+	if def.is_multiplier == false then mdef.is_multiplier = false
+	else mdef.is_multiplier = true end
+	if def.exclusive == true then mdef.exclusive = true
+	else mdef.exclusive = false end
+
+	mdef.on_start = def.on_start
+	mdef.on_end = def.on_end
+
+	if DEBUG then
+		minetest.log("FOV::Modifier Definition Registered:\n" .. dump(def))
+	end
+
+	mcl_fovapi.registered_modifiers[def.name] = mdef
+
+end
+
+minetest.register_on_respawnplayer(function(player)
+	mcl_fovapi.remove_all_modifiers(player)
+end)
+
+function mcl_fovapi.apply_modifier(player, modifier_name)
+	if not player or not modifier_name then
+		return
+	end
+	if mcl_fovapi.registered_modifiers[modifier_name] == nil then
+		return
+	end
+	local player_name = player:get_player_name()
+	if mcl_fovapi.applied_modifiers and mcl_fovapi.applied_modifiers[player_name] and mcl_fovapi.applied_modifiers[player_name][modifier_name] then
+		return
+	end
+
+	for k, _ in pairs(mcl_fovapi.applied_modifiers[player_name]) do
+		if mcl_fovapi.registered_modifiers[k].exclusive == true then return end
+	end
+
+	local modifier = mcl_fovapi.registered_modifiers[modifier_name]
+	if modifier.on_start then
+		modifier.on_start(player)
+	end
+
+	mcl_fovapi.applied_modifiers[player_name][modifier_name] = true -- set the applied to be true.
+
+	if DEBUG then
+		minetest.log("FOV::Player Applied Modifiers :" .. dump(mcl_fovapi.applied_modifiers[player_name]))
+	end
+
+	if DEBUG then
+		minetest.log("FOV::Modifier applied to player:" .. player_name .. " modifier: " .. modifier_name)
+	end
+
+	-- modifier apply code.
+	if modifier.exclusive == true then
+		-- if exclusive, reset the player's fov, and apply the new fov.
+		if modifier.is_multiplier then
+			player:set_fov(0, false, 0)
+		end
+		player:set_fov(modifier.fov_factor, modifier.is_multiplier, modifier.time)
+	else
+		-- not exclusive? let's apply it in the mix.
+		local fov_factor, is_mult = player:get_fov()
+		if fov_factor == 0 then
+			fov_factor = 1
+			is_mult = true
+		end
+		if modifier.is_multiplier or is_mult then
+			fov_factor = fov_factor * modifier.fov_factor
+		else
+			fov_factor = (fov_factor + modifier.fov_factor) / 2
+		end
+		if modifier.is_multiplier and is_mult then
+			player:set_fov(fov_factor, true, modifier.time)
+		else
+			player:set_fov(fov_factor, false, modifier.time)
+		end
+	end
+
+end
+
+function mcl_fovapi.remove_modifier(player, modifier_name)
+	if not player or not modifier_name then
+		return
+	end
+
+	local player_name = player:get_player_name()
+	if not mcl_fovapi.applied_modifiers[player_name]
+		or not mcl_fovapi.applied_modifiers[player_name][modifier_name] then
+			return
+	end
+
+	if DEBUG then
+		minetest.log("FOV::Player: " .. player_name .. " modifier: " .. modifier_name .. "removed.")
+	end
+
+	mcl_fovapi.applied_modifiers[player_name][modifier_name] = nil
+	local modifier = mcl_fovapi.registered_modifiers[modifier_name]
+
+	-- check for other fov modifiers, and set them up, or reset to default.
+
+	local applied = {}
+	for k, _ in pairs(mcl_fovapi.applied_modifiers[player_name]) do
+		applied[k] = mcl_fovapi.registered_modifiers[k]
+	end
+
+	local elem = next
+	if elem(applied) == nil then
+		player:set_fov(0, false, modifier.reset_time)
+		return
+	end
+	local exc = false
+	for k, _ in pairs(applied) do
+		if applied[k].exclusive == true then
+			exc = applied[k]
+			break
+		end
+	end
+
+	-- handle exclusives.
+	if exc ~= false then
+		player:set_fov(exc.fov_factor, exc.is_multiplier, 0) -- we want this to be immediate.
+	else
+		-- handle normal fov modifiers.
+		local fov_factor = 1
+		local non_multiplier_added = false
+		for _, x in pairs(applied) do
+			if not x.is_multiplier then
+				if non_multiplier_added then
+					fov_factor = (fov_factor + x.fov_factor) / 2
+				else
+					non_multiplier_added = true
+					fov_factor = fov_factor * x.fov_factor
+				end
+			else
+				fov_factor = fov_factor * x.fov_factor
+			end
+		end
+		player:set_fov(fov_factor, not non_multiplier_added, modifier.reset_time)
+	end
+
+	if mcl_fovapi.registered_modifiers[modifier_name].on_end then
+		mcl_fovapi.registered_modifiers[modifier_name].on_end(player)
+	end
+end
+
+function mcl_fovapi.remove_all_modifiers(player)
+	if not player then
+		return
+	end
+
+	local player_name = player:get_player_name()
+	if DEBUG then
+		minetest.log("FOV::Player: " .. player_name .. " modifiers have been reset.")
+	end
+
+	for name, x in pairs(mcl_fovapi.applied_modifiers[player_name]) do
+		x = nil
+		if mcl_fovapi.registered_modifiers[name].on_end then
+			mcl_fovapi.registered_modifiers[name].on_end(player)
+		end
+	end
+
+	player:set_fov(0, false, 0)
+end
+
+--[[
+Notes:
+set_fov(fov, is_multiplier, transition_time): Sets player's FOV
+
+    fov: FOV value.
+    is_multiplier: Set to true if the FOV value is a multiplier. Defaults to false.
+    transition_time: If defined, enables smooth FOV transition. Interpreted as the time (in seconds) to reach target FOV.
+    	If set to 0, FOV change is instantaneous. Defaults to 0.
+    Set fov to 0 to clear FOV override.
+
+--]]

mods/PLAYER/mcl_fovapi/mod.conf

@@ -0,0 +1,4 @@
+name = mcl_fovapi
+author = Michieal, Herowl
+description = An API for handling FOV changes.
+depends = mcl_player

mods/PLAYER/mcl_player/init.lua

@@ -177,7 +177,7 @@ minetest.register_on_joinplayer(function(player)
 	player_textures[name] = { "character.png", "blank.png", "blank.png" }
 
 	--player:set_local_animation({x=0, y=79}, {x=168, y=187}, {x=189, y=198}, {x=200, y=219}, 30)
-	player:set_fov(86.1) -- see <https://minecraft.gamepedia.com/Options#Video_settings>>>>
+-- 	player:set_fov(86.1) -- see <https://minecraft.gamepedia.com/Options#Video_settings>>>>
 end)
 
 minetest.register_on_leaveplayer(function(player)

mods/PLAYER/mcl_sprint/init.lua

@@ -64,40 +64,24 @@ local function cancelClientSprinting(name)
 	players[name].clientSprint = false
 end
 
+mcl_fovapi.register_modifier({
+	name = "sprint",
+	fov_factor = 1.1,
+	time = 0.15,
+	is_multiplier = true,
+})
+
 local function setSprinting(playerName, sprinting) --Sets the state of a player (0=stopped/moving, 1=sprinting)
 	if not sprinting and not mcl_sprint.is_sprinting(playerName) then return end
 	local player = minetest.get_player_by_name(playerName)
-	local controls = player:get_player_control()
 	if players[playerName] then
 		players[playerName].sprinting = sprinting
-		local fov_old = players[playerName].fov
-		local fov_new = fov_old
-		local fade_time = .15
-		if sprinting == true
-		or controls.RMB
-		and string.find(player:get_wielded_item():get_name(), "mcl_bows:bow")
-		and player:get_wielded_item():get_name() ~= "mcl_bows:bow" then
-			if sprinting == true then
-				fov_new = math.min(players[playerName].fov + 0.05, 1.2)
-			else
-				fov_new = .7
-				players[playerName].fade_time = .3
-			end
-			if sprinting == true then
-				playerphysics.add_physics_factor(player, "speed", "mcl_sprint:sprint", mcl_sprint.SPEED)
-			end
-		elseif sprinting == false
-		and player:get_wielded_item():get_name() ~= "mcl_bows:bow_0"
-		and player:get_wielded_item():get_name() ~= "mcl_bows:bow_1"
-		and player:get_wielded_item():get_name() ~= "mcl_bows:bow_2" then
-			fov_new = math.max(players[playerName].fov - 0.05, 1.0)
-			if sprinting == false then
-				playerphysics.remove_physics_factor(player, "speed", "mcl_sprint:sprint")
-			end
-		end
-		if fov_new ~= fov_old then
-			players[playerName].fov = fov_new
-			player:set_fov(fov_new, true, fade_time)
+		if sprinting then
+			playerphysics.add_physics_factor(player, "speed", "mcl_sprint:sprint", mcl_sprint.SPEED)
+			mcl_fovapi.apply_modifier(player, "sprint")
+		else
+			playerphysics.remove_physics_factor(player, "speed", "mcl_sprint:sprint")
+			mcl_fovapi.remove_modifier(player, "sprint")
 		end
 		return true
 	end

mods/PLAYER/mcl_sprint/mod.conf

@@ -1,4 +1,5 @@
 name = mcl_sprint
 author = GunshipPenguin
-description = Allows the player to sprint by pressing the “Use” key (default: E).
-depends = mcl_playerinfo, playerphysics, mcl_hunger
+description = Allows the player to sprint by pressing the “AUX” key (default: E).
+depends = mcl_playerinfo, playerphysics, mcl_hunger, mcl_fovapi
+optional = mcl_bows