init.lua

   1 -- Hangglider mod for Minetest
   2 -- Original code by Piezo_ (orderofthefourthwall@gmail.com)
   3 -- 2018-11-14
   4
   5 -- Modifications by David G (kestral246@gmail.com)
   6 -- 2018-11-24
   7 -- For Minetest 5.x, glider's set_attach needs to be offset by 1 node
   8 --     Switch to alternate commented line below with correct offset.
   9 -- Additional tuning of parameters.
  10 -- Commented out debug hud display code, prefixed with "--debug:".
  11
  12 -- 2018-11-22
  13 -- Give visual indication that hangglider is equiped.
  14 --     Display simple overlay with blurred struts when equiped.
  15 --     Issue: don't know how to disable overlay in third person view.
  16 -- Also Unequip hangglider when landing on water.
  17 -- Attempt to linearize parabolic flight path.
  18 --     Start gravity stronger, but gradually reduce it as descent velocity increases.
  19 --     Don't use airstopper when equipped from the ground (descent velocity is low).
  20 --     Slightly increase flight speed to 1.25.
  21 -- Unequip/equip cycling mid-flight should not fly farther than continuous flight.
  22 --     When equipping mid-air (descent velocity higher), use airstopper but increase descent slope afterwards.
  23 --     Create airbreak flag so all equips mid-flight use faster descent.
  24 --     Reset airbreak flag only when land (canExist goes false).
  25 --     Issue: it wouldn't reset if land in water, use fly, and launch from air, before I added test for water,
  26 --            not sure if there are other such cases.
  27 -- Temporarily add hud debug display to show descent velocity, gravity override, and airbreak flag.
  28 --     Still in process of tuning all the parameters.
  29
  30
  31 -- Modifications by Piezo_
  32 -- 2018-11-25
  33 -- hud overlay and debug can be enabled/disabled
  34 -- Added blender-rendered overlay for struts using the actual model.
  35 -- Reduced airbreak penalty severity
  36 -- gave glider limited durability.
  37 -- Improved gravity adjustment function.
  38 -- Changed airbreaking process
  39 -- Removed airbreak penalty, as any 'advantage' seems minimal after new adjustments
  40
  41
  42 local HUD_Overlay = true --show glider struts as overlay on HUD
  43 local debug = false --show debug info in top-center of hud
  44 hangglider = {} --Make this global, so other mods can tell if hangglider exists.
  45 hangglider.use = {}
  46 if HUD_Overlay then
  47 hangglider.id = {}  -- hud id for displaying overlay with struts
  48 end
  49 if debug then  hangglider.debug = {} end -- hud id for debug data
  50 --hangglider.airbreak = {}  -- true if falling fast when equip
  51
  52 minetest.register_entity("hangglider:airstopper", { --A one-instant entity that catches the player and stops them.
  53         is_visible = false,
  54         physical = false,
  55         immortal = true,
  56         attach = nil,
  57         on_step = function(self, _)
  58                 local canExist = false
  59                 if self.attach then
  60                         local player = self.attach
  61                         if player:is_player() then
  62                                 local pname = player:get_player_name()
  63                                 canExist = true
  64                                 if player:get_player_velocity().y < 0.5 and player:get_player_velocity().y > -0.5 then
  65                                         --Let go when the player actually stops, as that's the whole point.
  66                                         if hangglider.use[pname] then
  67                                                 minetest.add_entity(player:get_pos(), "hangglider:glider"):set_attach(player, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
  68                                         end
  69                                         canExist = false
  70                                 end
  71                         end
  72                         if not canExist then
  73                                 self.attach:set_detach()
  74                         end
  75                 end
  76                 if not canExist then
  77                         self.object:remove()
  78                 end
  79         end
  80 })
  81
  82 minetest.register_entity("hangglider:glider", {
  83         visual = "mesh",
  84         visual_size = {x = 12, y = 12},
  85         mesh = "glider.obj",
  86         immortal = true,
  87         static_save = false,
  88         textures = {"wool_white.png","default_wood.png"},
  89         on_step = function(self, _)
  90                 local canExist = false
  91                 if self.object:get_attach() then
  92                         local player = self.object:get_attach("parent")
  93                         if player then
  94                                 local pos = player:getpos()
  95                                 local pname = player:get_player_name()
  96                                 if hangglider.use[pname] then
  97                                         local mrn_name = minetest.registered_nodes[minetest.get_node(vector.new(pos.x, pos.y-0.5, pos.z)).name]
  98                                         if mrn_name then
  99                                                 if not (mrn_name.walkable or (mrn_name.drowning and mrn_name.drowning == 1)) then
 100                                                         canExist = true
 101                                                         local vel = player:get_player_velocity()
 102                                                         if debug then player:hud_change(hangglider.debug[pname].id, "text", vel.y..', '..grav..', '..tostring(hangglider.airbreak[pname])) end
 103
 104                                                         player:set_physics_override({gravity = (vel.y + 2.0)/20})
 105                                                 end
 106                                         end
 107                                 end
 108                                 if not canExist then
 109                                         player:set_physics_override({
 110                                                 gravity = 1,
 111                                                 jump = 1,
 112                                                 speed = 1,
 113                                         })
 114                                         hangglider.use[pname] = false
 115                                         if HUD_Overlay then
 116                                         player:hud_change(hangglider.id[pname], "text", "blank.png")
 117                                         end
 118                                         --hangglider.airbreak[pname] = false
 119                                 end
 120                         end
 121                 end
 122                 if not canExist then
 123                         self.object:set_detach()
 124                         self.object:remove()
 125                 end
 126         end
 127 })
 128
 129 minetest.register_on_dieplayer(function(player)
 130         player:set_physics_override({
 131                 gravity = 1,
 132                 jump = 1,
 133         })
 134         hangglider.use[player:get_player_name()] = false
 135 end)
 136
 137
 138 minetest.register_on_joinplayer(function(player)
 139         local pname = player:get_player_name()
 140         player:set_physics_override({
 141                 gravity = 1,
 142                 jump = 1,
 143         })
 144         hangglider.use[pname] = false
 145         if HUD_Overlay then
 146         hangglider.id[pname] = player:hud_add({
 147                 hud_elem_type = "image",
 148                 text = "blank.png",
 149                 position = {x=0, y=0},
 150                 scale = {x=-100, y=-100},
 151                 alignment = {x=1, y=1},
 152                 offset = {x=0, y=0}
 153         }) end
 154         if debug then
 155                 hangglider.debug[pname] = {id = player:hud_add({hud_elem_type = "text",
 156                         position = {x=0.5, y=0.1},
 157                         text = "-",
 158                         number = 0xFF0000}),  -- red text
 159                         -- ht = {50,50,50},
 160                 }
 161         end
 162         --hangglider.airbreak[pname] = false
 163 end)
 164
 165 minetest.register_on_leaveplayer(function(player)
 166         local pname = player:get_player_name()
 167         hangglider.use[pname] = nil
 168         if HUD_Overlay then hangglider.id[pname] = nil end
 169         if debug then hangglider.debug[pname] = nil end
 170         --hangglider.airbreak[pname] = nil
 171 end)
 172
 173 minetest.register_tool("hangglider:hangglider", {
 174         description = "Glider",
 175         inventory_image = "glider_item.png",
 176         stack_max=1,
 177         on_use = function(itemstack, user, pointed_thing)
 178                 if not user then
 179                         return
 180                 end
 181                 local pos = user:get_pos()
 182                 local pname = user:get_player_name()
 183                 if minetest.get_node(pos).name == "air" and not hangglider.use[pname] then --Equip
 184                         minetest.sound_play("bedsheet", {pos=pos, max_hear_distance = 8, gain = 1.0})
 185                         if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "glider_struts.png") end
 186                         local airbreak = false
 187                         local vel = user:get_player_velocity().y
 188                         if vel < -1.5 then  -- engage mid-air, falling fast, so stop but ramp velocity more quickly
 189                                 --hangglider.airbreak[pname] = true
 190                                 airbreak = true
 191                                 local stopper = minetest.add_entity(pos, "hangglider:airstopper")
 192                                 stopper:get_luaentity().attach = user
 193                                 user:set_attach( stopper, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
 194                         end
 195                         user:set_physics_override({gravity = 0,jump=0,speed=1.75})
 196                         if not airbreak then
 197
 198                                 minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
 199                         end
 200                         hangglider.use[pname] = true
 201                         -- if minetest 0.4.x use this:
 202
 203                         -- if minetest 5.x use this:
 204                         -- minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=10,z=0}, {x=0,y=0,z=0})
 205                         itemstack:set_wear(itemstack:get_wear() + 255)
 206                         return itemstack
 207                 elseif hangglider.use[pname] then --Unequip
 208                         if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "blank.png") end
 209                         hangglider.use[pname] = false
 210                 end
 211         end,
 212         sound = {breaks = "default_tool_breaks"},
 213 })
 214
 215 minetest.register_craft({
 216         output = "hangglider:hangglider",
 217         recipe = {
 218                 {"wool:white", "wool:white", "wool:white"},
 219                 {"default:stick", "", "default:stick"},
 220                 {"", "default:stick", ""},
 221         }
 222 })