player.lua

---- Player spawning/dying

local math = math
local table = table
local player = player
local timer = timer
local pairs = pairs

CreateConVar("ttt_bots_are_spectators", "0", FCVAR_ARCHIVE)
CreateConVar("ttt_dyingshot", "0")

CreateConVar("ttt_killer_dna_range", "550")
CreateConVar("ttt_killer_dna_basetime", "100")

-- First spawn on the server
function GM:PlayerInitialSpawn( ply )
   if not GAMEMODE.cvar_init then
      GAMEMODE:InitCvars()
   end

   ply:InitialSpawn()

   local rstate = GetRoundState() or ROUND_WAIT
   -- We should update the traitor list, if we are not about to send it
   if rstate <= ROUND_PREP then
      SendTraitorList(GetTraitorFilter())
      SendConfirmedTraitors(GetInnocentFilter())
      SendDetectiveList()
   end

   -- Game has started, tell this guy where the round is at
   if rstate != ROUND_WAIT then
      SendRoundState(rstate, ply)
      SendConfirmedTraitors(ply)
      SendDetectiveList(ply)
   end

   -- Handle spec bots
   if ply:IsBot() and GetConVar("ttt_bots_are_spectators"):GetBool() then
      ply:SetTeam(TEAM_SPEC)
      ply:SetForceSpec(true)
   end
end

function GM:NetworkIDValidated( name, steamid )
   -- edge case where player authed after initspawn
   for _, p in pairs(player.GetAll()) do
      if IsValid(p) and p:SteamID() == steamid and p.delay_karma_recall then
         KARMA.LateRecallAndSet(p)
         return
      end
   end
end

function GM:PlayerSpawn(ply)
   -- Some spawns may be tilted
   ply:ResetViewRoll()

   -- Clear out stuff like whether we ordered guns or what bomb code we used
   ply:ResetRoundFlags()

   -- latejoiner, send him some info
   if GetRoundState() == ROUND_ACTIVE then
      SendRoundState(GetRoundState(), ply)
   end

   ply.spawn_nick = ply:Nick()
   ply.has_spawned = true

   -- let the client do things on spawn
   net.Start("TTT_PlayerSpawned")
      net.WriteBit(ply:IsSpec())
   net.Send(ply)

   if ply:IsSpec() then
      ply:StripAll()
      ply:Spectate(OBS_MODE_ROAMING)
      return
   end

   ply:UnSpectate()

   -- ye olde hooks
   hook.Call("PlayerLoadout", GAMEMODE, ply)
   hook.Call("PlayerSetModel", GAMEMODE, ply)
   hook.Call("TTTPlayerSetColor", GAMEMODE, ply)

   local oldhands = ply:GetHands()
   if IsValid(oldhands) then oldhands:Remove() end

   local hands = ents.Create( "gmod_hands" )
   if IsValid(hands) then
      ply:SetHands(hands)
      hands:SetOwner(ply)

      -- Find model and attach to vm, currently ours
      ply:SetPlayerHands(ply)
      ply:DeleteOnRemove(hands)
      hands:Spawn()
   end

   SCORE:HandleSpawn(ply)
end

function GM:IsSpawnpointSuitable(ply, spwn, force, rigged)
   if not IsValid(ply) or not ply:IsTerror() then return true end
   if not rigged and (not IsValid(spwn) or not spwn:IsInWorld()) then return false end

   -- spwn is normally an ent, but we sometimes use a vector for jury rigged
   -- positions
   local pos = rigged and spwn or spwn:GetPos()

   if not util.IsInWorld(pos) then return false end

   local blocking = ents.FindInBox(pos + Vector( -16, -16, 0 ), pos + Vector( 16, 16, 64 ))

   for k, p in pairs(blocking) do
      if IsValid(p) and p:IsPlayer() and p:IsTerror() and p:Alive() then
         if force then
            p:Kill()
         else
            return false
         end
      end
   end

   return true
end

local SpawnTypes = {"info_player_deathmatch", "info_player_combine",
"info_player_rebel", "info_player_counterterrorist", "info_player_terrorist",
"info_player_axis", "info_player_allies", "gmod_player_start",
"info_player_teamspawn"}

function GetSpawnEnts(shuffled, force_all)
   local tbl = {}
   for k, classname in pairs(SpawnTypes) do
      for _, e in pairs(ents.FindByClass(classname)) do
         if IsValid(e) and (not e.BeingRemoved) then
            table.insert(tbl, e)
         end
      end
   end


   -- Don't use info_player_start unless absolutely necessary, because eg. TF2
   -- uses it for observer starts that are in places where players cannot really
   -- spawn well. At all.
   if force_all or #tbl == 0 then
      for _, e in pairs(ents.FindByClass("info_player_start")) do
         if IsValid(e) and (not e.BeingRemoved) then
            table.insert(tbl, e)
         end
      end
   end

   if shuffled then
      table.Shuffle(tbl)
   end

   return tbl
end

-- Generate points next to and above the spawn that we can test for suitability
local function PointsAroundSpawn(spwn)
   if not IsValid(spwn) then return {} end
   local pos = spwn:GetPos()

   local w, h = 36, 72 -- bit roomier than player hull

   -- all rigged positions
   -- could be done without typing them out, but would take about as much time
   return {
      pos + Vector( w,  0,  0),
      pos + Vector( 0,  w,  0),
      pos + Vector( w,  w,  0),
      pos + Vector(-w,  0,  0),
      pos + Vector( 0, -w,  0),
      pos + Vector(-w, -w,  0),
      pos + Vector(-w,  w,  0),
      pos + Vector( w, -w,  0)
      --pos + Vector( 0,  0,  h) -- just in case we're outside
   };
end

function GM:PlayerSelectSpawn(ply)
   if (not self.SpawnPoints) or (table.Count(self.SpawnPoints) == 0) or (not IsTableOfEntitiesValid(self.SpawnPoints)) then

      self.SpawnPoints = GetSpawnEnts(true, false)

      -- One might think that we have to regenerate our spawnpoint
      -- cache. Otherwise, any rigged spawn entities would not get reused, and
      -- MORE new entities would be made instead. In reality, the map cleanup at
      -- round start will remove our rigged spawns, and we'll have to create new
      -- ones anyway.
   end

   local num = table.Count(self.SpawnPoints)
   if num == 0 then
      Error("No spawn entity found!\n")
      return
   end

   -- Just always shuffle, it's not that costly and should help spawn
   -- randomness.
   table.Shuffle(self.SpawnPoints)

   -- Optimistic attempt: assume there are sufficient spawns for all and one is
   -- free
   for k, spwn in pairs(self.SpawnPoints) do
      if self:IsSpawnpointSuitable(ply, spwn, false) then
         return spwn
      end
   end

   -- That did not work, so now look around spawns
   local picked = nil

   for k, spwn in pairs(self.SpawnPoints) do
      picked = spwn -- just to have something if all else fails

      -- See if we can jury rig a spawn near this one
      local rigged = PointsAroundSpawn(spwn)
      for _, rig in pairs(rigged) do
         if self:IsSpawnpointSuitable(ply, rig, false, true) then
            local rig_spwn = ents.Create("info_player_terrorist")
            if IsValid(rig_spwn) then
               rig_spwn:SetPos(rig)
               rig_spwn:Spawn()

               ErrorNoHalt("TTT WARNING: Map has too few spawn points, using a rigged spawn for ".. tostring(ply) .. "\n")

               self.HaveRiggedSpawn = true
               return rig_spwn
            end
         end
      end
   end

   -- Last attempt, force one
   for k, spwn in pairs(self.SpawnPoints) do
      if self:IsSpawnpointSuitable(ply, spwn, true) then
         return spwn
      end
   end

   return picked
end


function GM:PlayerSetModel(ply)
   local mdl = GAMEMODE.playermodel or "models/player/phoenix.mdl"
   util.PrecacheModel(mdl)
   ply:SetModel(mdl)

   -- Always clear color state, may later be changed in TTTPlayerSetColor
   ply:SetColor(COLOR_WHITE)
end


function GM:TTTPlayerSetColor(ply)
   local clr = COLOR_WHITE
   local should_color = hook.Call("TTTShouldColorModel", GAMEMODE, ply:GetModel())
   if GAMEMODE.playercolor and should_color then
      -- If this player has a colorable model, always use the same color as all
      -- other colorable players, so color will never be the factor that lets
      -- you tell players apart.
      clr = GAMEMODE.playercolor
   end
   ply:SetColor(clr)
end


-- Only active players can use kill cmd
function GM:CanPlayerSuicide(ply)
   return ply:IsTerror()
end

function GM:PlayerSwitchFlashlight(ply, on)
   if not IsValid(ply) then return false end

   -- add the flashlight "effect" here, and then deny the switch
   -- this prevents the sound from playing, fixing the exploit
   -- where weapon sound could be silenced using the flashlight sound
   if (not on) or ply:IsTerror() then
      if on then
         ply:AddEffects(EF_DIMLIGHT)
      else
         ply:RemoveEffects(EF_DIMLIGHT)
      end
   end

   return false
end

function GM:PlayerSpray(ply)
   if not IsValid(ply) or not ply:IsTerror() then
      return true -- block
   end
end

function GM:PlayerUse(ply, ent)
   return ply:IsTerror()
end

function GM:KeyPress(ply, key)
   if not IsValid(ply) then return end

   -- Spectator keys
   if ply:IsSpec() and not ply:GetRagdollSpec() then

      if ply.propspec then
         return PROPSPEC.Key(ply, key)
      end

      ply:ResetViewRoll()

      if key == IN_ATTACK then
         -- snap to random guy
         ply:Spectate(OBS_MODE_ROAMING)
         ply:SpectateEntity(nil)

         local alive = util.GetAlivePlayers()

         if #alive < 1 then return end

         local target = table.Random(alive)
         if IsValid(target) then
            ply:SetPos(target:EyePos())
         end
      elseif key == IN_ATTACK2 then
         -- spectate either the next guy or a random guy in chase
         local target = util.GetNextAlivePlayer(ply:GetObserverTarget())

         if IsValid(target) then
            ply:Spectate(ply.spec_mode or OBS_MODE_CHASE)
            ply:SpectateEntity(target)
         end
      elseif key == IN_DUCK then
         local pos = ply:GetPos()
         local ang = ply:EyeAngles()

         local target = ply:GetObserverTarget()
         if IsValid(target) and target:IsPlayer() then
            pos = target:EyePos()
            ang = target:EyeAngles()
         end

         -- reset
         ply:Spectate(OBS_MODE_ROAMING)
         ply:SpectateEntity(nil)

         ply:SetPos(pos)
         ply:SetEyeAngles(ang)
         return true
      elseif key == IN_JUMP then
         -- unfuck if you're on a ladder etc
         if not (ply:GetMoveType() == MOVETYPE_NOCLIP) then
            ply:SetMoveType(MOVETYPE_NOCLIP)
         end
      elseif key == IN_RELOAD then
         local tgt = ply:GetObserverTarget()
         if not IsValid(tgt) or not tgt:IsPlayer() then return end

         if not ply.spec_mode or ply.spec_mode == OBS_MODE_CHASE then
            ply.spec_mode = OBS_MODE_IN_EYE
         elseif ply.spec_mode == OBS_MODE_IN_EYE then
            ply.spec_mode = OBS_MODE_CHASE
         end
         -- roam stays roam

         ply:Spectate(ply.spec_mode)
      end
   end

end


function GM:KeyRelease(ply, key)
   if key == IN_USE and IsValid(ply) and ply:IsTerror() then
      -- see if we need to do some custom usekey overriding
      local tr = util.TraceLine({
         start  = ply:GetShootPos(),
         endpos = ply:GetShootPos() + ply:GetAimVector() * 84,
         filter = ply,
         mask   = MASK_SHOT
      });

      if tr.Hit and IsValid(tr.Entity) then
         if tr.Entity.CanUseKey and tr.Entity.UseOverride then
            local phys = tr.Entity:GetPhysicsObject()
            if IsValid(phys) and not phys:HasGameFlag(FVPHYSICS_PLAYER_HELD) then
               tr.Entity:UseOverride(ply)
               return true
            else
               -- do nothing, can't +use held objects
               return true
            end
         elseif tr.Entity.player_ragdoll then
            CORPSE.ShowSearch(ply, tr.Entity, (ply:KeyDown(IN_WALK) or ply:KeyDownLast(IN_WALK)))
            return true
         end
      end
   end

end

function GM:PlayerButtonUp(ply, btn)
   -- Would be nice to clean up this whole "all key handling in massive
   -- functions" thing. oh well
   if btn == KEY_PAD_ENTER then
      WEPS.DisguiseToggle(ply)
   end
end

-- Normally all dead players are blocked from IN_USE on the server, meaning we
-- can't let them search bodies. This sucks because searching bodies is
-- fun. Hence on the client we override +use for specs and use this instead.
local function SpecUseKey(ply, cmd, arg)
   if IsValid(ply) and ply:IsSpec() then
      -- longer range than normal use
      local tr = util.QuickTrace(ply:GetShootPos(), ply:GetAimVector() * 128, ply)
      if tr.Hit and IsValid(tr.Entity) then
         if tr.Entity.player_ragdoll then
            if not ply:KeyDown(IN_WALK) then
               CORPSE.ShowSearch(ply, tr.Entity)
            else
               ply:Spectate(OBS_MODE_IN_EYE)
               ply:SpectateEntity(tr.Entity)
            end
         elseif tr.Entity:IsPlayer() and tr.Entity:IsActive() then
            ply:Spectate(ply.spec_mode or OBS_MODE_CHASE)
            ply:SpectateEntity(tr.Entity)
         else
            PROPSPEC.Target(ply, tr.Entity)
         end
      end
   end
end
concommand.Add("ttt_spec_use", SpecUseKey)

function GM:PlayerDisconnected(ply)
   -- Prevent the disconnecter from being in the resends
   if IsValid(ply) then
      ply:SetRole(ROLE_NONE)
   end

   if GetRoundState() != ROUND_PREP then
      -- Keep traitor entindices in sync on traitor clients
      SendTraitorList(GetTraitorFilter(false), nil)

      -- Same for confirmed traitors on innocent clients
      SendConfirmedTraitors(GetInnocentFilter(false))

      SendDetectiveList()
   end


   if KARMA.IsEnabled() then
      KARMA.Remember(ply)
   end
end

---- Death affairs

local function CreateDeathEffect(ent, marked)
   local pos = ent:GetPos() + Vector(0, 0, 20)

   local jit = 35.0

   local jitter = Vector(math.Rand(-jit, jit), math.Rand(-jit, jit), 0)
   util.PaintDown(pos + jitter, "Blood", ent)

   if marked then
      util.PaintDown(pos, "Cross", ent)
   end
end

local deathsounds = {
   Sound("player/death1.wav"),
   Sound("player/death2.wav"),
   Sound("player/death3.wav"),
   Sound("player/death4.wav"),
   Sound("player/death5.wav"),
   Sound("player/death6.wav"),
   Sound("vo/npc/male01/pain07.wav"),
   Sound("vo/npc/male01/pain08.wav"),
   Sound("vo/npc/male01/pain09.wav"),
   Sound("vo/npc/male01/pain04.wav"),
   Sound("vo/npc/Barney/ba_pain06.wav"),
   Sound("vo/npc/Barney/ba_pain07.wav"),
   Sound("vo/npc/Barney/ba_pain09.wav"),
   Sound("vo/npc/Barney/ba_ohshit03.wav"), --heh
   Sound("vo/npc/Barney/ba_no01.wav"),
   Sound("vo/npc/male01/no02.wav"),
   Sound("hostage/hpain/hpain1.wav"),
   Sound("hostage/hpain/hpain2.wav"),
   Sound("hostage/hpain/hpain3.wav"),
   Sound("hostage/hpain/hpain4.wav"),
   Sound("hostage/hpain/hpain5.wav"),
   Sound("hostage/hpain/hpain6.wav")
};


local function PlayDeathSound(victim)
   if not IsValid(victim) then return end

   sound.Play(table.Random(deathsounds), victim:GetShootPos(), 90, 100)
end

-- See if we should award credits now
local function CheckCreditAward(victim, attacker)
   if GetRoundState() != ROUND_ACTIVE then return end
   if not IsValid(victim) then return end

   -- DETECTIVE AWARD
   if IsValid(attacker) and attacker:IsPlayer() and attacker:IsActiveDetective() and victim:IsTraitor() then
      local amt = GetConVarNumber("ttt_det_credits_traitordead") or 1
      for _, ply in pairs(player.GetAll()) do
         if ply:IsActiveDetective() then
            ply:AddCredits(amt)
         end
      end

      LANG.Msg(GetDetectiveFilter(true), "credit_det_all", {num = amt})
   end


   -- TRAITOR AWARD
   if (not victim:IsTraitor()) and (not GAMEMODE.AwardedCredits or GetConVar("ttt_credits_award_repeat"):GetBool()) then
      local inno_alive = 0
      local inno_dead = 0
      for _, ply in pairs(player.GetAll()) do
         if not ply:GetTraitor() then
            if ply:IsTerror() then
               inno_alive = inno_alive + 1
            elseif ply:IsDeadTerror() then
               inno_dead = inno_dead + 1
            end
         end
      end

      -- we check this at the death of an innocent who is still technically
      -- Alive(), so add one to dead count and sub one from living
      inno_dead = inno_dead + 1
      inno_alive = math.max(inno_alive - 1, 0)
      inno_total = inno_dead + inno_alive

      -- Only repeat-award if we have reached the pct again since last time
      if GAMEMODE.AwardedCredits then
         inno_dead = inno_dead - GAMEMODE.AwardedCreditsDead
      end

      local pct = inno_dead / inno_total
      if pct >= GetConVarNumber("ttt_credits_award_pct") then
         -- Traitors have killed sufficient people to get an award
         local amt = GetConVarNumber("ttt_credits_award_size")

         -- If size is 0, awards are off
         if amt > 0 then
            LANG.Msg(GetTraitorFilter(true), "credit_tr_all", {num = amt})

            for _, ply in pairs(player.GetAll()) do
               if ply:IsActiveTraitor() then
                  ply:AddCredits(amt)
               end
            end
         end

         GAMEMODE.AwardedCredits = true
         GAMEMODE.AwardedCreditsDead = inno_dead + GAMEMODE.AwardedCreditsDead
      end
   end
end

function GM:DoPlayerDeath(ply, attacker, dmginfo)
   if ply:IsSpec() then return end

   -- Experimental: Fire a last shot if ironsighting and not headshot
   if GetConVar("ttt_dyingshot"):GetBool() then
      local wep = ply:GetActiveWeapon()
      if IsValid(wep) and wep.DyingShot and not ply.was_headshot and dmginfo:IsBulletDamage() then
         local fired = wep:DyingShot()
         if fired then
            return
         end
      end

      -- Note that funny things can happen here because we fire a gun while the
      -- player is dead. Specifically, this DoPlayerDeath is run twice for
      -- him. This is ugly, and we have to return the first one to prevent crazy
      -- shit.
   end

   -- Drop all weapons
   for k, wep in pairs(ply:GetWeapons()) do
      WEPS.DropNotifiedWeapon(ply, wep, true) -- with ammo in them
      wep:DampenDrop()
   end

   if IsValid(ply.hat) then
      ply.hat:Drop()
   end

   -- Create ragdoll and hook up marking effects
   local rag = CORPSE.Create(ply, attacker, dmginfo)
   ply.server_ragdoll = rag -- nil if clientside

   CreateDeathEffect(ply, false)

   util.StartBleeding(rag, dmginfo:GetDamage(), 15)

   -- Score only when there is a round active.
   if GetRoundState() == ROUND_ACTIVE then
      SCORE:HandleKill(ply, attacker, dmginfo)

      if IsValid(attacker) and attacker:IsPlayer() then
         attacker:RecordKill(ply)

         DamageLog(Format("KILL:\t %s [%s] killed %s [%s]", attacker:Nick(), attacker:GetRoleString(), ply:Nick(), ply:GetRoleString()))
      else
         DamageLog(Format("KILL:\t <something/world> killed %s [%s]", ply:Nick(), ply:GetRoleString()))
      end


      KARMA.Killed(attacker, ply, dmginfo)
   end

   -- Clear out any weapon or equipment we still have
   ply:StripAll()

   -- Tell the client to send their chat contents
   ply:SendLastWords(dmginfo)

   local killwep = util.WeaponFromDamage(dmginfo)

   -- headshots, knife damage, and weapons tagged as silent all prevent death
   -- sound from occurring
   if not (ply.was_headshot or
           dmginfo:IsDamageType(DMG_SLASH) or
           (IsValid(killwep) and killwep.IsSilent)) then
      PlayDeathSound(ply)
   end

   --- Credits

   CheckCreditAward(ply, attacker)

   -- Check for T killing D or vice versa
   if IsValid(attacker) and attacker:IsPlayer() then
      local reward = 0
      if attacker:IsActiveTraitor() and ply:GetDetective() then
         reward = math.ceil(GetConVarNumber("ttt_credits_detectivekill"))
      elseif attacker:IsActiveDetective() and ply:GetTraitor() then
         reward = math.ceil(GetConVarNumber("ttt_det_credits_traitorkill"))
      end

      if reward > 0 then
         attacker:AddCredits(reward)

         LANG.Msg(attacker, "credit_kill", {num = reward,
                                            role = LANG.NameParam(ply:GetRoleString())})
      end
   end
end

function GM:PlayerDeath( victim, infl, attacker)
   -- tell no one
   self:PlayerSilentDeath(victim)

   victim:SetTeam(TEAM_SPEC)
   victim:Freeze(false)
   victim:SetRagdollSpec(true)
   victim:Spectate(OBS_MODE_IN_EYE)

   local rag_ent = victim.server_ragdoll or victim:GetRagdollEntity()
   victim:SpectateEntity(rag_ent)

   victim:Flashlight(false)

   victim:Extinguish()

   net.Start("TTT_PlayerDied") net.Send(ply)

   if HasteMode() and GetRoundState() == ROUND_ACTIVE then
      IncRoundEnd(GetConVar("ttt_haste_minutes_per_death"):GetFloat() * 60)
   end
end

-- kill hl2 beep
function GM:PlayerDeathSound() return true end


function GM:SpectatorThink(ply)
   -- when spectating a ragdoll after death
   if ply:GetRagdollSpec() then
      local to_switch, to_chase, to_roam = 2, 5, 8
      local elapsed = CurTime() - ply.spec_ragdoll_start
      local clicked = ply:KeyPressed(IN_ATTACK)

      -- After first click, go into chase cam, then after another click, to into
      -- roam. If no clicks made, go into chase after X secs, and roam after Y.
      -- Don't switch for a second in case the player was shooting when he died,
      -- this would make him accidentally switch out of ragdoll cam.

      local m = ply:GetObserverMode()
      if (m == OBS_MODE_CHASE and clicked) or elapsed > to_roam then
         -- free roam mode
         ply:SetRagdollSpec(false)
         ply:Spectate(OBS_MODE_ROAMING)

         -- move to spectator spawn if mapper defined any
         local spec_spawns = ents.FindByClass("ttt_spectator_spawn")
         if spec_spawns and #spec_spawns > 0 then
            local spawn = table.Random(spec_spawns)
            ply:SetPos(spawn:GetPos())
            ply:SetEyeAngles(spawn:GetAngles())
         end
      elseif (m == OBS_MODE_IN_EYE and clicked and elapsed > to_switch) or elapsed > to_chase then
         -- start following ragdoll
         ply:Spectate(OBS_MODE_CHASE)
      end

      if not IsValid(ply.server_ragdoll) then ply:SetRagdollSpec(false) end

   -- when roaming and messing with ladders
   elseif ply:GetMoveType() < MOVETYPE_NOCLIP and ply:GetMoveType() > 0 or ply:GetMoveType() == MOVETYPE_LADDER then
      ply:Spectate(OBS_MODE_ROAMING)
   end

   -- when speccing a player
   if ply:GetObserverMode() != OBS_MODE_ROAMING and (not ply.propspec) and (not ply:GetRagdollSpec()) then
      local tgt = ply:GetObserverTarget()
      if IsValid(tgt) and tgt:IsPlayer() then
         if (not tgt:IsTerror()) or (not tgt:Alive()) then
            -- stop speccing as soon as target dies
            ply:Spectate(OBS_MODE_ROAMING)
            ply:SpectateEntity(nil)
         elseif GetRoundState() == ROUND_ACTIVE then
            -- Sync position to target. Uglier than parenting, but unlike
            -- parenting this is less sensitive to breakage: if we are
            -- no longer spectating, we will never sync to their position.
            ply:SetPos(tgt:GetPos())
         end
      end
   end
end

GM.PlayerDeathThink = GM.SpectatorThink

function GM:PlayerTraceAttack(ply, dmginfo, dir, trace)
   if IsValid(ply.hat) and trace.HitGroup == HITGROUP_HEAD then
      ply.hat:Drop(dir)
   end

   ply.hit_trace = trace

   return false
end

function GM:ScalePlayerDamage(ply, hitgroup, dmginfo)
   if dmginfo:IsBulletDamage() and ply:HasEquipmentItem(EQUIP_ARMOR) then
      -- Body armor nets you a damage reduction.
      dmginfo:ScaleDamage(0.7)
   end

   ply.was_headshot = false
   -- actual damage scaling
   if hitgroup == HITGROUP_HEAD then
      -- headshot if it was dealt by a bullet
      ply.was_headshot = dmginfo:IsBulletDamage()

      local wep = util.WeaponFromDamage(dmginfo)

      if IsValid(wep) then
         local s = wep:GetHeadshotMultiplier(ply, dmginfo) or 2
         dmginfo:ScaleDamage(s)
      end
   elseif (hitgroup == HITGROUP_LEFTARM or
           hitgroup == HITGROUP_RIGHTARM or
           hitgroup == HITGROUP_LEFTLEG or
           hitgroup == HITGROUP_RIGHTLEG or
           hitgroup == HITGROUP_GEAR ) then

      dmginfo:ScaleDamage(0.55)
   end

   -- Keep ignite-burn damage etc on old levels
   if (dmginfo:IsDamageType(DMG_DIRECT) or
       dmginfo:IsExplosionDamage() or
       dmginfo:IsDamageType(DMG_FALL) or
       dmginfo:IsDamageType(DMG_PHYSGUN)) then
      dmginfo:ScaleDamage(2)
   end
end

-- The GetFallDamage hook does not get called until around 600 speed, which is a
-- rather high drop already. Hence we do our own fall damage handling in
-- OnPlayerHitGround.
function GM:GetFallDamage(ply, speed)
   return 1
end

local fallsounds = {
   Sound("player/damage1.wav"),
   Sound("player/damage2.wav"),
   Sound("player/damage3.wav")
};

function GM:OnPlayerHitGround(ply, in_water, on_floater, speed)
   if in_water or speed < 450 or not IsValid(ply) then return end

   -- Everything over a threshold hurts you, rising exponentially with speed
   local damage = math.pow(0.05 * (speed - 420), 1.75)

   -- I don't know exactly when on_floater is true, but it's probably when
   -- landing on something that is in water.
   if on_floater then damage = damage / 2 end

   -- if we fell on a dude, that hurts (him)
   local ground = ply:GetGroundEntity()
   if IsValid(ground) and ground:IsPlayer() then
      if math.floor(damage) > 0 then
         local att = ply

         -- if the faller was pushed, that person should get attrib
         local push = ply.was_pushed
         if push then
            -- TODO: move push time checking stuff into fn?
            if math.max(push.t or 0, push.hurt or 0) > CurTime() - 4 then
               att = push.att
            end
         end

         local dmg = DamageInfo()

         if att == ply then
            -- hijack physgun damage as a marker of this type of kill
            dmg:SetDamageType(DMG_CRUSH + DMG_PHYSGUN)
         else
            -- if attributing to pusher, show more generic crush msg for now
            dmg:SetDamageType(DMG_CRUSH)
         end

         dmg:SetAttacker(att)
         dmg:SetInflictor(att)
         dmg:SetDamageForce(Vector(0,0,-1))
         dmg:SetDamage(damage)

         ground:TakeDamageInfo(dmg)
      end

      -- our own falling damage is cushioned
      damage = damage / 3
   end

   if math.floor(damage) > 0 then
      local dmg = DamageInfo()
      dmg:SetDamageType(DMG_FALL)
      dmg:SetAttacker(game.GetWorld())
      dmg:SetInflictor(game.GetWorld())
      dmg:SetDamageForce(Vector(0,0,1))
      dmg:SetDamage(damage)

      ply:TakeDamageInfo(dmg)

      -- play CS:S fall sound if we got somewhat significant damage
      if damage > 5 then
         sound.Play(table.Random(fallsounds), ply:GetShootPos(), 55 + math.Clamp(damage, 0, 50), 100)
      end
   end
end

local ttt_postdm = CreateConVar("ttt_postround_dm", "0", FCVAR_NOTIFY)

function GM:AllowPVP()
   local rs = GetRoundState()
   return not (rs == ROUND_PREP or (rs == ROUND_POST and not ttt_postdm:GetBool()))
end

-- No damage during prep, etc
function GM:EntityTakeDamage(ent, dmginfo)
   if not IsValid(ent) then return end
   local att = dmginfo:GetAttacker()

   if not GAMEMODE:AllowPVP() then
      -- if player vs player damage, or if damage versus a prop, then zero
      if (ent:IsExplosive() or (ent:IsPlayer() and IsValid(att) and att:IsPlayer())) then
         dmginfo:ScaleDamage(0)
         dmginfo:SetDamage(0)
      end
   elseif ent:IsPlayer() then

      GAMEMODE:PlayerTakeDamage(ent, dmginfo:GetInflictor(), att, dmginfo:GetDamage(), dmginfo)

   elseif ent:IsExplosive() then
      -- When a barrel hits a player, that player damages the barrel because
      -- Source physics. This gives stupid results like a player who gets hit
      -- with a barrel being blamed for killing himself or even his attacker.
      if IsValid(att) and att:IsPlayer() and
         dmginfo:IsDamageType(DMG_CRUSH) and
         IsValid(ent:GetPhysicsAttacker()) then

         dmginfo:SetAttacker(ent:GetPhysicsAttacker())
         dmginfo:ScaleDamage(0)
         dmginfo:SetDamage(0)
      end
   elseif ent.is_pinned and ent.OnPinnedDamage then
      ent:OnPinnedDamage(dmginfo)

      dmginfo:SetDamage(0)
   end
end

function GM:PlayerTakeDamage(ent, infl, att, amount, dmginfo)
   -- Change damage attribution if necessary
   if infl or att then
      local hurter, owner, owner_time

      -- fall back to the attacker if there is no inflictor
      if IsValid(infl) then
         hurter = infl
      elseif IsValid(att) then
         hurter = att
      end

      -- have a damage owner?
      if hurter and IsValid(hurter:GetDamageOwner()) then
         owner, owner_time = hurter:GetDamageOwner()

         -- barrel bangs can hurt us even if we threw them, but that's our fault
      elseif hurter and ent == hurter:GetPhysicsAttacker() and dmginfo:IsDamageType(DMG_BLAST) then
         owner = ent
      end


      -- if we were hurt by a trap OR by a non-ply ent, and we were pushed
      -- recently, then our pusher is the attacker
      if owner_time or (not IsValid(att)) or (not att:IsPlayer()) then
         local push = ent.was_pushed

         if push and IsValid(push.att) and push.t then
            -- push must be within the last 5 seconds, and must be done
            -- after the trap was enabled (if any)
            owner_time = owner_time or 0
            local t = math.max(push.t or 0, push.hurt or 0)
            if t > owner_time and t > CurTime() - 4 then
               owner = push.att

               -- pushed by a trap?
               if IsValid(push.infl) then
                  dmginfo:SetInflictor(push.infl)
               end

               -- for slow-hurting traps we do leech-like damage timing
               push.hurt = CurTime()
            end
         end
      end

      -- if we are being hurt by a physics object, we will take damage from
      -- the world entity as well, which screws with damage attribution so we
      -- need to detect and work around that
      if IsValid(owner) and dmginfo:IsDamageType(DMG_CRUSH) then
         -- we should be able to use the push system for this, as the cases are
         -- similar: event causes future damage but should still be attributed
         -- physics traps can also push you to your death, for example
         local push = ent.was_pushed or {}

         -- if we already blamed this on a pusher, no need to do more
         -- else we override whatever was in was_pushed with info pointing
         -- at our damage owner
         if push.att != owner then
            owner_time = owner_time or CurTime()

            push.att = owner
            push.t = owner_time
            push.hurt = CurTime()

            -- store the current inflictor so that we can attribute it as the
            -- trap used by the player in the event
            if IsValid(infl) then
               push.infl = infl
            end

            -- make sure this is set, for if we created a new table
            ent.was_pushed = push
         end
      end

      -- make the owner of the damage the attacker
      att = IsValid(owner) and owner or att
      dmginfo:SetAttacker(att)
   end

   -- scale phys damage caused by props
   if dmginfo:IsDamageType(DMG_CRUSH) and IsValid(att) then

      -- player falling on player, or player hurt by prop?
      if not dmginfo:IsDamageType(DMG_PHYSGUN) then

         -- this is prop-based physics damage
         dmginfo:ScaleDamage(0.25)

         -- if the prop is held, no damage
         if IsValid(infl) and IsValid(infl:GetOwner()) and infl:GetOwner():IsPlayer() then
            dmginfo:ScaleDamage(0)
            dmginfo:SetDamage(0)
         end
      end
   end

   -- handle fire attacker
   if ent.ignite_info and dmginfo:IsDamageType(DMG_DIRECT) then
      local datt = dmginfo:GetAttacker()
      if (not IsValid(datt)) or (not datt:IsPlayer()) then
         local ignite = ent.ignite_info
         if IsValid(ignite.att) and IsValid(ignite.infl)then
            dmginfo:SetAttacker(ignite.att)
            dmginfo:SetInflictor(ignite.infl)
         end
      end
   end

   -- try to work out if this was push-induced leech-water damage (common on
   -- some popular maps like dm_island17)
   if ent.was_pushed and ent == att and dmginfo:GetDamageType() == DMG_GENERIC and util.BitSet(util.PointContents(dmginfo:GetDamagePosition()), CONTENTS_WATER) then
      local t = math.max(ent.was_pushed.t or 0, ent.was_pushed.hurt or 0)
      if t > CurTime() - 3 then
         dmginfo:SetAttacker(ent.was_pushed.att)
         ent.was_pushed.hurt = CurTime()
      end
   end

   -- start painting blood decals
   util.StartBleeding(ent, dmginfo:GetDamage(), 5)

   -- general actions for pvp damage
   if ent != att and IsValid(att) and att:IsPlayer() and GetRoundState() == ROUND_ACTIVE and math.floor(dmginfo:GetDamage()) > 0 then

      -- scale everything to karma damage factor except the knife, because it
      -- assumes a kill
      if not dmginfo:IsDamageType(DMG_SLASH) then
         dmginfo:ScaleDamage(att:GetDamageFactor())
      end

      -- process the effects of the damage on karma
      KARMA.Hurt(att, ent, dmginfo)

      DamageLog(Format("DMG: \t %s [%s] damaged %s [%s] for %d dmg", att:Nick(), att:GetRoleString(), ent:Nick(), ent:GetRoleString(), math.Round(dmginfo:GetDamage())))
   end

end


function GM:OnNPCKilled() end

-- Drowning and such
local tm = nil
local ply = nil
local plys = nil
function GM:Tick()
   -- three cheers for micro-optimizations
   plys = player.GetAll()
   for i= 1, #plys do
      ply = plys[i]
      tm = ply:Team()
      if tm == TEAM_TERROR and ply:Alive() then
         -- Drowning
         if ply:WaterLevel() == 3 then
            if ply:IsOnFire() then
               ply:Extinguish()
            end

            if ply.drowning then
               if ply.drowning < CurTime() then
                  local dmginfo = DamageInfo()
                  dmginfo:SetDamage(15)
                  dmginfo:SetDamageType(DMG_DROWN)
                  dmginfo:SetAttacker(game.GetWorld())
                  dmginfo:SetInflictor(game.GetWorld())
                  dmginfo:SetDamageForce(Vector(0,0,1))

                  ply:TakeDamageInfo(dmginfo)

                  -- have started drowning properly
                  ply.drowning = CurTime() + 1
               end
            else
               -- will start drowning soon
               ply.drowning = CurTime() + 8
            end
         else
            ply.drowning = nil
         end

         -- Slow down ironsighters
         local wep = ply:GetActiveWeapon()
         if IsValid(wep) and wep.GetIronsights and wep:GetIronsights() then
            ply:SetSpeed(true)
         else
            ply:SetSpeed(false)
         end

         -- Run DNA Scanner think also when it is not deployed
         if IsValid(ply.scanner_weapon) and wep != ply.scanner_weapon then
            ply.scanner_weapon:Think()
         end
      elseif tm == TEAM_SPEC then
         if ply.propspec then
            PROPSPEC.Recharge(ply)

            if IsValid(ply:GetObserverTarget()) then
               ply:SetPos(ply:GetObserverTarget():GetPos())
            end
         end

         -- if spectators are alive, ie. they picked spectator mode, then
         -- DeathThink doesn't run, so we have to SpecThink here
         if ply:Alive() then
            self:SpectatorThink(ply)
         end
      end
   end
end

function GM:ShowHelp(ply)
   if IsValid(ply) then
      ply:ConCommand("ttt_helpscreen")
   end
end

function GM:PlayerRequestTeam(ply, teamid)
end

-- Implementing stuff that should already be in gmod, chpt. 389
function GM:PlayerEnteredVehicle(ply, vehicle, role)
   if IsValid(vehicle) then
      vehicle:SetNWEntity("ttt_driver", ply)
   end
end

function GM:PlayerLeaveVehicle(ply, vehicle)
   if IsValid(vehicle) then
      -- setting nil will not do anything, so bogusify
      vehicle:SetNWEntity("ttt_driver", vehicle)
   end
end

function GM:AllowPlayerPickup(ply, obj)
   return false
end

function GM:PlayerShouldTaunt(ply, actid)
   -- Disable taunts, we don't have a system for them (camera freezing etc).
   -- Mods/plugins that add such a system should override this.
   return false
end