Work around wrong character bone rotations on Luanti 5.11+ (#6)

Fixes head turning more than 90 degrees during minor lag, which appears unnatural.

README.md

@@ -12,15 +12,8 @@ Created by [Rui](https://github.com/Rui-Minetest), this document was written by
 ### Version of player model
 
 Player models supported by this mod:
-- `MTG_4_Jun_2017` (minetest_game after 4 Jun 2017, 0.4.16)
+- minetest_game after 4 Jun 2017, Minetest 0.4.16
-- `MTG_4_Nov_2017` (minetest_game after 4 Nov 2017, 0.5.0)
+- minetest_game after 4 Nov 2017, Minetest 0.5.0-dev
-
-As there is no automatic way to determine which version is used, this must be configured with advanced settings menu, or by manually editing `playeranim.model_version` entry in minetest.conf.  
-The default value is `MTG_4_Jun_2017`.
-
-Symptoms of having configured the incorrect player model:
-- In rest, arms are raised up, and are either detached from the body, or are too close to the body
-- Cape (if visible) points upward
 
 ### The delay of sideways body rotation
 

init.lua

@@ -1,3 +1,8 @@
+
+if not minetest.settings then
+	error("Mod playeranim requires Minetest 0.4.16 or newer")
+end
+
 local ANIMATION_SPEED = tonumber(minetest.settings:get("playeranim.animation_speed")) or 2.4
 local ANIMATION_SPEED_SNEAK = tonumber(minetest.settings:get("playeranim.animation_speed_sneak")) or 0.8
 local BODY_ROTATION_DELAY = math.max(math.floor(tonumber(minetest.settings:get("playeranim.body_rotation_delay")) or 7), 1)
@@ -9,11 +14,30 @@ local BONE_POSITION, BONE_ROTATION = (function()
 	return dofile(modpath .. "/model.lua")
 end)()
 
-local get_animation = player_api and player_api.get_animation or default.player_get_animation
+local get_animation = minetest.global_exists("player_api")
+	and player_api.get_animation or default.player_get_animation
 if not get_animation then
 	error("player_api.get_animation or default.player_get_animation is not found")
 end
 
+-- stop player_api from messing stuff up (since 5.3)
+if minetest.global_exists("player_api") then
+	minetest.register_on_mods_loaded(function()
+		for _, model in pairs(player_api.registered_models) do
+			if model.animations then
+				for _, animation in pairs(model.animations) do
+					animation.x = 0
+					animation.y = 0
+				end
+			end
+		end
+	end)
+
+	minetest.register_on_joinplayer(function(player)
+		player:set_local_animation(nil, nil, nil, nil, 0)
+	end)
+end
+
 local function get_animation_speed(player)
 	if player:get_player_control().sneak then
 		return ANIMATION_SPEED_SNEAK
@@ -101,6 +125,17 @@ minetest.register_on_joinplayer(function(player)
 	players_animation_data:init_player(player)
 end)
 
+-- HACK work around https://github.com/luanti-org/luanti/issues/15692
+-- Scales corresponding to default perfect 180° rotations in the character b3d model
+local bone_workaround_scales = {
+	Body = vector.new(-1, 1, -1),
+	Arm_Left = vector.new(1, -1, -1),
+	Arm_Right = vector.new(1, -1, -1),
+	Leg_Left = vector.new(1, -1, -1),
+	Leg_Right = vector.new(1, -1, -1),
+	Cape = vector.new(1, -1, -1),
+}
+
 local vector_add, vector_equals = vector.add, vector.equals
 local function rotate_bone(player, bone, rotation, position_optional)
 	local previous_rotation = players_animation_data:get_bone_rotation(player, bone)
@@ -116,9 +151,17 @@ local function rotate_bone(player, bone, rotation, position_optional)
 	or not previous_position
 	or not vector_equals(rotation, previous_rotation)
 	or not vector_equals(position, previous_position) then
-		player:set_bone_position(bone, position, rotation)
+		if player.set_bone_override then -- Luanti 5.9+
-		players_animation_data:set_bone_rotation(player, bone, rotation)
+			player:set_bone_override(bone, {
-		players_animation_data:set_bone_position(player, bone, position)
+				position = {vec = position, absolute = true},
+				rotation = {vec = rotation:apply(math.rad), absolute = true},
+				scale = {vec = bone_workaround_scales[bone], absolute = true},
+			})
+		else
+			player:set_bone_position(bone, position, rotation)
+			players_animation_data:set_bone_rotation(player, bone, rotation)
+			players_animation_data:set_bone_position(player, bone, position)
+		end
 	end
 end
 
@@ -237,7 +280,14 @@ local function rotate_body_and_head(player)
 		if #yaw_history > BODY_ROTATION_DELAY then
 			local body_yaw = table_remove(yaw_history, 1)
 			local player_yaw = player:get_look_horizontal()
-			return math_deg(player_yaw - body_yaw)
+			-- Get the difference and normalize it to [-180,180) range.
+			-- This will give the shortest rotation between head and body angles.
+			local angle = ((player_yaw - body_yaw + 3.0*math_pi) % (2.0*math_pi)) - math_pi
+			-- Arbitrary limit of the head turn angle
+			local limit = math_pi*0.3 -- value from 0 to pi, less than 0.45*pi looks good
+			-- Clamp the value to the limit
+			angle = math.max(math.min(angle, limit), -limit)
+			return math_deg(angle)
 		end
 		return 0
 	end)()
@@ -250,7 +300,15 @@ end
 
 
 local function animate_player(player, dtime)
-	local animation = get_animation(player).animation
+	local data = get_animation(player)
+	if not data then
+		-- Minetest Engine workaround for 5.6.0-dev and older
+		-- minetest.register_globalstep may call to this function before the player is
+		-- initialized by minetest.register_on_joinplayer in player_api
+		return
+	end
+
+	local animation = data.animation
 
 	-- Yaw history
 	if animation == "lay" or animation == "sit" then

model.lua

@@ -7,22 +7,8 @@ local RARM = "Arm_Right"
 local LLEG = "Leg_Left"
 local RLEG = "Leg_Right"
 
--- Version of player model
-local DEFAULT_PLAYER_MODEL_VERSION = "MTG_4_Jun_2017"
-
-local VALID_PLAYER_MODEL_VERSIONS = {
-	MTG_4_Jun_2017 = true,
-	MTG_4_Nov_2017 = true,
-}
-
-local LEGACY_PLAYER_MODEL_VERSIONS = {
-	default_character_v1 = true,
-	default_character_v2 = true,
-	default_character_v3 = true,
-}
-
 local BONE_POSITIONS = {
-	MTG_4_Jun_2017 = {
+	MTG_0_4_x = {
 		[BODY] = {x = 0,   y = -3.5, z = 0},
 		[HEAD] = {x = 0,   y = 6.5,  z = 0},
 		[CAPE] = {x = 0,   y = 6.5,  z = 1.2},
@@ -34,7 +20,7 @@ local BONE_POSITIONS = {
 		body_sit = {x = 0, y = -5.5, z = 0},
 		body_lay = {x = 0, y = -5.5, z = 0},
 	},
-	MTG_4_Nov_2017 = {
+	MTG_5_0_x = {
 		[BODY] = {x = 0,   y = 6.25, z = 0},
 		[HEAD] = {x = 0,   y = 6.5,  z = 0},
 		[CAPE] = {x = 0,   y = 6.5,  z = 1.2},
@@ -49,7 +35,7 @@ local BONE_POSITIONS = {
 }
 
 local BONE_ROTATIONS = {
-	MTG_4_Jun_2017 = {
+	MTG_0_4_x = {
 		[BODY] = {x = 0, y = 0, z = 0},
 		[HEAD] = {x = 0, y = 0, z = 0},
 		[CAPE] = {x = 0, y = 0, z = 0},
@@ -61,7 +47,7 @@ local BONE_ROTATIONS = {
 		body_sit = {x = 0,   y = 0, z = 0},
 		body_lay = {x = 270, y = 0, z = 0},
 	},
-	MTG_4_Nov_2017 = {
+	MTG_5_0_x = {
 		[BODY] = {x = 0, y = 0, z = 0},
 		[HEAD] = {x = 0, y = 0, z = 0},
 		[CAPE] = {x = 0, y = 0, z = 0},
@@ -75,23 +61,10 @@ local BONE_ROTATIONS = {
 	},
 }
 
-local PLAYER_MODEL_VERSION = (function()
+local model = minetest.global_exists("player_api") and "MTG_5_0_x" or "MTG_0_4_x"
-	local version = minetest.settings:get("playeranim.model_version")
-	if version == nil or version == "" then
-		version = DEFAULT_PLAYER_MODEL_VERSION
-	end
 
-	if LEGACY_PLAYER_MODEL_VERSIONS[version] then
+local BONE_POSITION = BONE_POSITIONS[model]
-		error("The model version '" .. version .. "' is no longer suppported")
+local BONE_ROTATION = BONE_ROTATIONS[model]
-	elseif not VALID_PLAYER_MODEL_VERSIONS[version] then
-		error("Invalid value for playeranim.model_version in minetest.conf: " .. version)
-	end
-
-	return version
-end)()
-
-local BONE_POSITION = BONE_POSITIONS[PLAYER_MODEL_VERSION]
-local BONE_ROTATION = BONE_ROTATIONS[PLAYER_MODEL_VERSION]
 if not BONE_POSITION or not BONE_ROTATION then
 	error("Internal error: invalid player_model_version: " .. PLAYER_MODEL_VERSION)
 end

settingtypes.txt

@@ -1,10 +1,3 @@
-#    Version of player model.
-#
-#    Player models supported by this mod:
-#    . -- `MTG_4_Jun_2017` (minetest_game after 4 Jun 2017, 0.4.16)
-#    . -- `MTG_4_Nov_2017` (minetest_game after 4 Nov 2017, 0.5.0)
-playeranim.model_version (Version of player model) enum MTG_4_Jun_2017 MTG_4_Jun_2017,MTG_4_Nov_2017
-
 #    The number of frame delay of sideways body rotation. (between 1 and 20).
 playeranim.body_rotation_delay (The delay of sideways body rotation) int 7 1 20