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
  38
  39 local HUD_Overlay = true --show glider struts as overlay on HUD
  40 local debug = false --show debug info in top-center of hud
  41 hangglider = {} --Make this global, so other mods can tell if hangglider exists.
  42 hangglider.use = {}
  43 if HUD_Overlay then
  44 hangglider.id = {}  -- hud id for displaying overlay with struts
  45 end
  46 if debug then  hangglider.debug = {} end -- hud id for debug data
  47 hangglider.airbreak = {}  -- true if falling fast when equip
  48
  49 minetest.register_entity("hangglider:airstopper", { --A one-instant entity that catches the player and slows them down.
  50         hp_max = 3,
  51         is_visible = false,
  52         immortal = true,
  53         attach = nil,
  54         on_step = function(self, _)
  55                 if self.object:get_hp() ~= 1 then
  56                         self.object:set_hp(self.object:get_hp() - 1)
  57                 else
  58                         if self.attach then
  59                                 self.attach:set_detach()
  60                         end
  61                         self.object:remove()
  62                 end
  63         end
  64 })
  65
  66 minetest.register_entity("hangglider:glider", {
  67         visual = "mesh",
  68         visual_size = {x = 12, y = 12},
  69         mesh = "glider.obj",
  70         immortal = true,
  71         static_save = false,
  72         textures = {"wool_white.png","default_wood.png"},
  73         on_step = function(self, _)
  74                 local canExist = false
  75                 if self.object:get_attach() then
  76                         local player = self.object:get_attach("parent")
  77                         if player then
  78                                 local pos = player:getpos()
  79                                 local pname = player:get_player_name()
  80                                 if hangglider.use[pname] then
  81                                         local mrn_name = minetest.registered_nodes[minetest.get_node(vector.new(pos.x, pos.y-0.5, pos.z)).name]
  82                                         if mrn_name then
  83                                                 if not (mrn_name.walkable or (mrn_name.drowning and mrn_name.drowning == 1)) then
  84                                                         canExist = true
  85                                                         local vel = player:get_player_velocity()
  86                                                         local grav = player:get_physics_override().gravity
  87                                                         if debug then player:hud_change(hangglider.debug[pname].id, "text", vel.y..', '..grav..', '..tostring(hangglider.airbreak[pname])) end
  88                                                         -- If airbreaking used, increase the descent progression to not give
  89                                                         -- mid-flight unequip/equip cycles a distance advantage.
  90                                                         if hangglider.airbreak[pname] then
  91                                                                 if vel.y <= -4.0 then
  92                                                                         grav = -0.2 --Extreme measures are needed, as sometimes speed will get a bit out of control
  93                                                                 elseif vel.y <= -2.0 then
  94                                                                         grav = -0.02
  95                                                                 elseif vel.y <= -1.75 then
  96                                                                         grav = 0.00125  -- *1
  97                                                                 elseif vel.y <= -1.5 then
  98                                                                         grav = 0.0025  -- *2
  99                                                                 elseif vel.y <= -1.25 then
 100                                                                         grav = 0.005  -- *2
 101                                                                 elseif vel.y <= -1 then
 102                                                                         grav = 0.015  -- *3
 103                                                                 elseif vel.y <= -0.75 then
 104                                                                         grav = 0.04  -- *4
 105                                                                 elseif vel.y <= -0.5 then
 106                                                                         grav = 0.08  -- *4
 107                                                                 elseif vel.y <= -0.25 then
 108                                                                         grav = 0.12  -- *3
 109                                                                 elseif vel.y <= 0 then
 110                                                                         grav = 0.3  -- *3
 111                                                                 else  -- vel.y > 0
 112                                                                         grav = 0.75  -- *1.5
 113                                                                 end
 114                                                         else  -- normal descent progression
 115                                                                 if vel.y <= -4.0 then
 116                                                                         grav = -0.2
 117                                                                 elseif vel.y <= -2.0 then
 118                                                                         grav = -0.02
 119                                                                 elseif vel.y <= -1.5 then
 120                                                                         grav = 0.00125
 121                                                                 elseif vel.y <= -1.25 then
 122                                                                         grav = 0.0025
 123                                                                 elseif vel.y <= -1 then
 124                                                                         grav = 0.005
 125                                                                 elseif vel.y <= -0.75 then
 126                                                                         grav = 0.01
 127                                                                 elseif vel.y <= -0.5 then
 128                                                                         grav = 0.02
 129                                                                 elseif vel.y <= -0.25 then
 130                                                                         grav = 0.04
 131                                                                 elseif vel.y <= 0 then
 132                                                                         grav = 0.1
 133                                                                 else  -- vel.y > 0
 134                                                                         grav = 0.5
 135                                                                 end
 136                                                         end
 137                                                         player:set_physics_override({gravity = grav})
 138                                                 end
 139                                         end
 140                                 end
 141                                 if not canExist then
 142                                         player:set_physics_override({
 143                                                 gravity = 1,
 144                                                 jump = 1,
 145                                                 speed = 1,
 146                                         })
 147                                         hangglider.use[pname] = false
 148                                         if HUD_Overlay then
 149                                         player:hud_change(hangglider.id[pname], "text", "blank.png")
 150                                         end
 151                                         hangglider.airbreak[pname] = false
 152                                 end
 153                         end
 154                 end
 155                 if not canExist then
 156                         self.object:set_detach()
 157                         self.object:remove()
 158                 end
 159         end
 160 })
 161
 162 minetest.register_on_dieplayer(function(player)
 163         player:set_physics_override({
 164                 gravity = 1,
 165                 jump = 1,
 166         })
 167         hangglider.use[player:get_player_name()] = false
 168 end)
 169
 170
 171 minetest.register_on_joinplayer(function(player)
 172         local pname = player:get_player_name()
 173         player:set_physics_override({
 174                 gravity = 1,
 175                 jump = 1,
 176         })
 177         hangglider.use[pname] = false
 178         if HUD_Overlay then
 179         hangglider.id[pname] = player:hud_add({
 180                 hud_elem_type = "image",
 181                 text = "blank.png",
 182                 position = {x=0, y=0},
 183                 scale = {x=-100, y=-100},
 184                 alignment = {x=1, y=1},
 185                 offset = {x=0, y=0}
 186         }) end
 187         if debug then
 188                 hangglider.debug[pname] = {id = player:hud_add({hud_elem_type = "text",
 189                         position = {x=0.5, y=0.1},
 190                         text = "-",
 191                         number = 0xFF0000}),  -- red text
 192                         -- ht = {50,50,50},
 193                 }
 194         end
 195         hangglider.airbreak[pname] = false
 196 end)
 197
 198 minetest.register_on_leaveplayer(function(player)
 199         local pname = player:get_player_name()
 200         hangglider.use[pname] = nil
 201         if HUD_Overlay then hangglider.id[pname] = nil end
 202         if debug then hangglider.debug[pname] = nil end
 203         hangglider.airbreak[pname] = nil
 204 end)
 205
 206 minetest.register_tool("hangglider:hangglider", {
 207         description = "Glider",
 208         inventory_image = "glider_item.png",
 209         stack_max=1,
 210         on_use = function(itemstack, user, pointed_thing)
 211                 if not user then
 212                         return
 213                 end
 214                 local pos = user:get_pos()
 215                 local pname = user:get_player_name()
 216                 if minetest.get_node(pos).name == "air" and not hangglider.use[pname] then --Equip
 217                         minetest.sound_play("bedsheet", {pos=pos, max_hear_distance = 8, gain = 1.0})
 218                         if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "glider_struts.png") end
 219                         local vel = user:get_player_velocity().y
 220                         if vel < -0.8 then  -- engage mid-air, falling fast, so stop but ramp velocity more quickly
 221                                 hangglider.airbreak[pname] = true
 222                                 user:set_physics_override({
 223                                         gravity = 1,
 224                                         jump = 0,
 225                                         speed = 1.75,
 226                                 })
 227                                 local stopper = minetest.add_entity(pos, "hangglider:airstopper")
 228                                 stopper:get_luaentity().attach = user
 229                                 user:set_attach( stopper, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
 230                         else
 231                                 user:set_physics_override({
 232                                         gravity = 0.02,
 233                                         jump = 0,
 234                                         speed = 1.75,
 235                                 })
 236                         end
 237                         hangglider.use[pname] = true
 238                         -- if minetest 0.4.x use this:
 239                         minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
 240                         -- if minetest 5.x use this:
 241                         -- minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=10,z=0}, {x=0,y=0,z=0})
 242                         itemstack:set_wear(itemstack:get_wear() + 255)
 243                         return itemstack
 244                 elseif hangglider.use[pname] then --Unequip
 245                         if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "blank.png") end
 246                         hangglider.use[pname] = false
 247                 end
 248         end,
 249         sound = {breaks = "default_tool_breaks"},
 250 })
 251
 252 minetest.register_craft({
 253         output = "hangglider:hangglider",
 254         recipe = {
 255                 {"wool:white", "wool:white", "wool:white"},
 256                 {"default:stick", "", "default:stick"},
 257                 {"", "default:stick", ""},
 258         }
 259 })