update player model remove vertial 1 node offset on newer engines only

* Player model: Remove vertical 1 node offset for new engines, but
  Required due to the settable player collision box engine feature
  change for MT/MTG v0.5.0 that breaks compatibility with old client
  so due that this commit will added backguard compatibility
* Autodetec minetest versoin engine and provide right model
  character, update player code to provide compatibility with player_api

mods/default/legacy.lua

@@ -23,3 +23,27 @@ LIGHT_MAX = default.LIGHT_MAX
 
 -- Formspecs
 default.gui_suvival_form = default.gui_survival_form
+default.gui_bg     = ""
+default.gui_bg_img = ""
+default.gui_slots  = ""
+
+-- Players
+if minetest.get_modpath("player_api") then
+	default.registered_player_models = player_api.registered_models
+	default.player_register_model    = player_api.register_model
+	default.player_attached          = player_api.player_attached
+	default.player_get_animation     = player_api.get_animation
+	default.player_set_model         = player_api.set_model
+	default.player_set_textures      = player_api.set_textures
+	default.player_set_animation     = player_api.set_animation
+else
+	player_api = {}
+	player_api.registered_models = default.registered_player_models
+	player_api.register_model = default.player_register_model
+	player_api.player_attached = default.player_attached
+	player_api.get_animation = default.player_get_animation
+	player_api.set_model = default.player_set_model
+	player_api.set_textures = default.player_set_textures
+	player_api.set_animation = default.player_set_animation
+end
+

mods/default/mod.conf

@@ -0,0 +1,2 @@
+name = default
+description = Minetest Game mod: default

mods/default/player.lua

@@ -4,6 +4,17 @@
 -- Player animation blending
 -- Note: This is currently broken due to a bug in Irrlicht, leave at 0
 local animation_blend = 0
+local modelchar
+
+local is_50 = minetest.has_feature("object_use_texture_alpha") or nil
+
+if is_50 then
+	modelchar = "character50.b3d"
+	eyeheithg = 1.47
+else
+	modelchar = "character40.b3d"
+	eyeheithg = 1.625
+end
 
 default.registered_player_models = { }
 
@@ -14,22 +25,6 @@ function default.player_register_model(name, def)
 	models[name] = def
 end
 
--- Default player appearance
-default.player_register_model("character.b3d", {
-	animation_speed = 30,
-	textures = {"character.png", },
-	animations = {
-		-- Standard animations.
-		stand     = { x=  0, y= 79, },
-		lay       = { x=162, y=166, },
-		walk      = { x=168, y=187, },
-		mine      = { x=189, y=198, },
-		walk_mine = { x=200, y=219, },
-		sit       = { x= 81, y=160, },
-	},
-	eye_height = 1.625,
-})
-
 -- Player stats and animations
 local player_model = {}
 local player_textures = {}
@@ -58,15 +53,20 @@ function default.player_set_model(player, model_name)
 			mesh = model_name,
 			textures = player_textures[name] or model.textures,
 			visual = "mesh",
-			visual_size = model.visual_size or {x=1, y=1},
-			eye_height = model.eye_height or 1.47,
+			visual_size = model.visual_size or {x = 1, y = 1},
+			collisionbox = model.collisionbox or {-0.3, 0.0, -0.3, 0.3, 1.7, 0.3},
+			stepheight = model.stepheight or 0.6,
+			eye_height = model.eye_height or eyeheithg,
 		})
 		default.player_set_animation(player, "stand")
 	else
 		player:set_properties({
-			textures = { "player.png", "player_back.png", },
+			textures = {"player.png", "player_back.png"},
 			visual = "upright_sprite",
-			eye_height = 1.625,
+			visual_size = {x = 1, y = 2},
+			collisionbox = {-0.3, 0.0, -0.3, 0.3, 1.75, 0.3},
+			stepheight = 0.6,
+			eye_height = eyeheithg,
 		})
 	end
 	player_model[name] = model_name
@@ -74,8 +74,10 @@ end
 
 function default.player_set_textures(player, textures)
 	local name = player:get_player_name()
-	player_textures[name] = textures
-	player:set_properties({textures = textures,})
+	local model = models[player_model[name]]
+	local model_textures = model and model.textures or nil
+	player_textures[name] = textures or model_textures
+	player:set_properties({textures = textures or model_textures,})
 end
 
 function default.player_set_animation(player, anim_name, speed)
@@ -92,14 +94,36 @@ function default.player_set_animation(player, anim_name, speed)
 	player:set_animation(anim, speed or model.animation_speed, animation_blend)
 end
 
+
+-- Default player appearance
+default.player_register_model( modelchar, {
+	animation_speed = 30,
+	textures = {"character.png", },
+	animations = {
+		-- Standard animations.
+		stand     = {x = 0,   y = 79},
+		lay       = {x = 162, y = 166},
+		walk      = {x = 168, y = 187},
+		mine      = {x = 189, y = 198},
+		walk_mine = {x = 200, y = 219},
+		sit       = {x = 81,  y = 160},
+	},
+	collisionbox = {-0.3, 0.0, -0.3, 0.3, 1.7, 0.3},
+	stepheight = 0.6,
+	eye_height = eyeheithg,
+})
+
 -- Update appearance when the player joins
 minetest.register_on_joinplayer(function(player)
 	default.player_attached[player:get_player_name()] = false
-	default.player_set_model(player, "character.b3d")
-	player:set_local_animation({x=0, y=79}, {x=168, y=187}, {x=189, y=198}, {x=200, y=219}, 30)
-
-	player:hud_set_hotbar_image("gui_hotbar.png")
-	player:hud_set_hotbar_selected_image("gui_hotbar_selected.png")
+	default.player_set_model(player, modelchar)
+	player:set_local_animation(
+		{x = 0,   y = 79},
+		{x = 168, y = 187},
+		{x = 189, y = 198},
+		{x = 200, y = 219},
+		30
+	)
 end)
 
 minetest.register_on_leaveplayer(function(player)
@@ -113,6 +137,15 @@ end)
 local player_set_animation = default.player_set_animation
 local player_attached = default.player_attached
 
+-- Prevent knockback for attached players
+local old_calculate_knockback = minetest.calculate_knockback
+function minetest.calculate_knockback(player, ...)
+	if player_attached[player:get_player_name()] then
+		return 0
+	end
+	return old_calculate_knockback(player, ...)
+end
+
 -- Check each player and apply animations
 minetest.register_globalstep(function(dtime)
 	for _, player in pairs(minetest.get_connected_players()) do