(*
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2004-2012 Andrey Korotaev <unC0Rr@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *)

{$INCLUDE "options.inc"}

unit uGears;
(*
 * This unit defines the behavior of gears.
 *
 * Gears are "things"/"objects" that may be visible to the player or not,
 * but always have an effect on the course of the game.
 *
 * E.g.: weapons, hedgehogs, etc.
 *
 * Note: The visual appearance of gears is defined in the unit "uGearsRender".
 *
 * Note: Gears that do not have an effect on the game but are just visual
 *       effects are called "Visual Gears" and defined in the respective unit!
 *)
interface
uses SDLh, uConsts, uFloat, uTypes, uLandObjects;

procedure initModule;
procedure freeModule;
function  SpawnCustomCrateAt(x, y: LongInt; crate: TCrateType; content, cnt: Longword): PGear;
function  SpawnFakeCrateAt(x, y: LongInt; crate: TCrateType; explode: boolean; poison: boolean ): PGear;
function  GetAmmo(Hedgehog: PHedgehog): TAmmoType;
function  GetUtility(Hedgehog: PHedgehog): TAmmoType;
procedure HideHog(HH: PHedgehog);
procedure RestoreHog(HH: PHedgehog);
procedure ProcessGears;
procedure EndTurnCleanup;
procedure SetAllToActive;
procedure SetAllHHToActive;
procedure DrawGears;
procedure FreeGearsList;
procedure AddMiscGears;
procedure AssignHHCoords;
function  GearByUID(uid : Longword) : PGear;
procedure doStepDrowningGear(Gear: PGear);


implementation
uses uStore, uSound, uTeams, uRandom, uCollisions, uIO, uLandGraphics,
    uLocale, uAI, uAmmos, uStats, uVisualGears, uScript, GLunit, uMobile, uVariables,
    uCommands, uUtils, uTextures, uRenderUtils, uGearsRender, uCaptions, uDebug, uLandTexture,
    uGearsHedgehog, uGearsUtils, uGearsList, uGearsHandlers, uGearsHandlersRope;

var skipFlag: boolean;

procedure AmmoShove(Ammo: PGear; Damage, Power: LongInt); forward;
//procedure AmmoFlameWork(Ammo: PGear); forward;
function  GearsNear(X, Y: hwFloat; Kind: TGearType; r: LongInt): PGearArrayS; forward;
procedure SpawnBoxOfSmth; forward;
procedure ShotgunShot(Gear: PGear); forward;
procedure doStepCase(Gear: PGear); forward;


var delay: LongWord;
    delay2: LongWord;
    step: (stDelay, stChDmg, stSweep, stTurnReact,
    stAfterDelay, stChWin, stWater, stChWin2, stHealth,
    stSpawn, stNTurn);
    upd: Longword;
    snowLeft,snowRight: LongInt;
    //SDMusic: shortstring;

// For better maintainability the step handlers of gears are stored in
// separate files.
// Note: step handlers of gears that are hedgehogs are in a different file
//       than the handlers for all other gears.
{$INCLUDE "GSHandlers.inc"}

function CheckNoDamage: boolean; // returns TRUE in case of no damaged hhs
var Gear: PGear;
    dmg: LongInt;
begin
CheckNoDamage:= true;
Gear:= GearsList;
while Gear <> nil do
    begin
    if (Gear^.Kind = gtHedgehog) and (((GameFlags and gfInfAttack) = 0) or ((Gear^.dX.QWordValue < _0_000004.QWordValue)
    and (Gear^.dY.QWordValue < _0_000004.QWordValue))) then
        begin
        if (not isInMultiShoot) then
            inc(Gear^.Damage, Gear^.Karma);
        if (Gear^.Damage <> 0) and (not Gear^.Invulnerable) then
            begin
            CheckNoDamage:= false;

            dmg:= Gear^.Damage;
            if Gear^.Health < dmg then
                begin
                Gear^.Active:= true;
                Gear^.Health:= 0
                end
            else
                dec(Gear^.Health, dmg);

            if (Gear^.Hedgehog^.Team = CurrentTeam) and (Gear^.Damage <> Gear^.Karma)
            and (not Gear^.Hedgehog^.King) and (Gear^.Hedgehog^.Effects[hePoisoned] = 0) and (not SuddenDeathDmg) then
                Gear^.State:= Gear^.State or gstLoser;

            spawnHealthTagForHH(Gear, dmg);

            RenderHealth(Gear^.Hedgehog^);
            RecountTeamHealth(Gear^.Hedgehog^.Team);

            end;
        if (not isInMultiShoot) then
            Gear^.Karma:= 0;
        Gear^.Damage:= 0
        end;
    Gear:= Gear^.NextGear
    end;
end;

procedure HealthMachine;
var Gear: PGear;
    team: PTeam;
    i: LongWord;
    flag: Boolean;
    tmp: LongWord;
begin
    Gear:= GearsList;

    while Gear <> nil do
    begin
        if Gear^.Kind = gtHedgehog then
            begin
            tmp:= 0;
            if Gear^.Hedgehog^.Effects[hePoisoned] <> 0 then
                begin
                inc(tmp, ModifyDamage(5, Gear));
                if (GameFlags and gfResetHealth) <> 0 then
                    dec(Gear^.Hedgehog^.InitialHealth)  // does not need a minimum check since <= 1 basically disables it
                end;
            if (TotalRounds > cSuddenDTurns - 1) then
                begin
                inc(tmp, cHealthDecrease);
                if (GameFlags and gfResetHealth) <> 0 then
                    dec(Gear^.Hedgehog^.InitialHealth, cHealthDecrease)
                end;
            if Gear^.Hedgehog^.King then
                begin
                flag:= false;
                team:= Gear^.Hedgehog^.Team;
                for i:= 0 to Pred(team^.HedgehogsNumber) do
                    if (team^.Hedgehogs[i].Gear <> nil) and (not team^.Hedgehogs[i].King)
                    and (team^.Hedgehogs[i].Gear^.Health > team^.Hedgehogs[i].Gear^.Damage) then
                        flag:= true;
                if not flag then
                    begin
                    inc(tmp, 5);
                    if (GameFlags and gfResetHealth) <> 0 then
                        dec(Gear^.Hedgehog^.InitialHealth, 5)
                    end
                end;
            if tmp > 0 then 
                begin
                inc(Gear^.Damage, min(tmp, max(0,Gear^.Health - 1 - Gear^.Damage)));
                HHHurt(Gear^.Hedgehog, dsPoison);
                end
            end;

        Gear:= Gear^.NextGear
    end;
end;

procedure ProcessGears;
var t: PGear;
    i, AliveCount: LongInt;
    s: shortstring;
begin
PrvInactive:= AllInactive;
AllInactive:= true;

if (StepSoundTimer > 0) and (StepSoundChannel < 0) then
    StepSoundChannel:= LoopSound(sndSteps)
else if (StepSoundTimer = 0) and (StepSoundChannel > -1) then
    begin
    StopSoundChan(StepSoundChannel);
    StepSoundChannel:= -1
    end;

if StepSoundTimer > 0 then
    dec(StepSoundTimer, 1);

t:= GearsList;
while t <> nil do
    begin
    curHandledGear:= t;
    t:= curHandledGear^.NextGear;

    if curHandledGear^.Message and gmDelete <> 0 then
        DeleteGear(curHandledGear)
    else
        begin
        if curHandledGear^.Message and gmRemoveFromList <> 0 then 
            begin
            RemoveGearFromList(curHandledGear);
            // since I can't think of any good reason this would ever be separate from a remove from list, going to keep it inside this block
            if curHandledGear^.Message and gmAddToList <> 0 then InsertGearToList(curHandledGear);
            curHandledGear^.Message:= curHandledGear^.Message and (not (gmRemoveFromList or gmAddToList))
            end;
        if curHandledGear^.Active then
            begin
            if curHandledGear^.RenderTimer and (curHandledGear^.Timer > 500) and ((curHandledGear^.Timer mod 1000) = 0) then
                begin
                FreeTexture(curHandledGear^.Tex);
                curHandledGear^.Tex:= RenderStringTex(inttostr(curHandledGear^.Timer div 1000), cWhiteColor, fntSmall);
                end;
            curHandledGear^.doStep(curHandledGear);
            // might be useful later
            //ScriptCall('onGearStep', Gear^.uid);
            end
        end
    end;
curHandledGear:= nil;

if AllInactive then
case step of
    stDelay:
        begin
        if delay = 0 then
            delay:= cInactDelay
        else
            dec(delay);

        if delay = 0 then
            inc(step)
        end;
        
    stChDmg:
    if CheckNoDamage then
        inc(step)
    else
        step:= stDelay;
        
    stSweep:
    if SweepDirty then
        begin
        SetAllToActive;
        step:= stChDmg
        end
    else
        inc(step);
        
    stTurnReact:
        begin
        if (not bBetweenTurns) and (not isInMultiShoot) then
            begin
            uStats.TurnReaction;
            inc(step)
            end
        else
            inc(step, 2);
        end;
        
    stAfterDelay:
        begin
        if delay = 0 then
            delay:= cInactDelay
        else
            dec(delay);

        if delay = 0 then
            inc(step)
            end;
    stChWin:
        begin
        CheckForWin();
        inc(step)
        end;
    stWater:
    if (not bBetweenTurns) and (not isInMultiShoot) then
        begin
        if TotalRounds = cSuddenDTurns + 1 then
            bWaterRising:= true;
        if bWaterRising and (cWaterRise > 0) then
            AddGear(0, 0, gtWaterUp, 0, _0, _0, 0)^.Tag:= cWaterRise;
        inc(step)
        end
    else // since we are not raising the water, a second win-check isn't needed
        inc(step,2);
    stChWin2:
        begin
        CheckForWin;
        inc(step)
        end;

    stHealth:
        begin
        if (cWaterRise <> 0) or (cHealthDecrease <> 0) then
             begin
            if (TotalRounds = cSuddenDTurns) and (not SuddenDeath) and (not isInMultiShoot) then
                begin
                SuddenDeath:= true;
                if cHealthDecrease <> 0 then
                    begin
                    SuddenDeathDmg:= true;
                        
                    // flash
                    ScreenFade:= sfFromWhite;
                    ScreenFadeValue:= sfMax;
                    ScreenFadeSpeed:= 1;
                    
                    ChangeToSDClouds;
                    ChangeToSDFlakes;
                    glClearColor(SDSkyColor.r * (SDTint/255) / 255, SDSkyColor.g * (SDTint/255) / 255, SDSkyColor.b * (SDTint/255) / 255, 0.99);
                    Ammoz[amTardis].SkipTurns:= 9999;
                    Ammoz[amTardis].Probability:= 0;
                    end;
                AddCaption(trmsg[sidSuddenDeath], cWhiteColor, capgrpGameState);
                playSound(sndSuddenDeath);
                StopMusic //No SDMusic for now
                    //ChangeMusic(SDMusic)
                    end
                else if (TotalRounds < cSuddenDTurns) and (not isInMultiShoot) then
                    begin
                    i:= cSuddenDTurns - TotalRounds;
                    s:= inttostr(i);
                    if i = 1 then
                        AddCaption(trmsg[sidRoundSD], cWhiteColor, capgrpGameState)
                    else if (i = 2) or ((i > 0) and ((i mod 50 = 0) or ((i <= 25) and (i mod 5 = 0)))) then
                        AddCaption(Format(trmsg[sidRoundsSD], s), cWhiteColor, capgrpGameState);
                    end;
                end;
            if bBetweenTurns
            or isInMultiShoot
            or (TotalRounds = -1) then
                inc(step)
            else
                begin
                bBetweenTurns:= true;
                HealthMachine;
                step:= stChDmg
                end
            end;
    stSpawn:
        begin
        if not isInMultiShoot then
            SpawnBoxOfSmth;
        inc(step)
        end;
    stNTurn:
        begin
        if isInMultiShoot then
            isInMultiShoot:= false
        else
            begin
            // delayed till after 0.9.12
            // reset to default zoom
            //ZoomValue:= ZoomDefault;
            with CurrentHedgehog^ do
                if (Gear <> nil)
                and ((Gear^.State and gstAttacked) = 0)
                and (MultiShootAttacks > 0) then
                    OnUsedAmmo(CurrentHedgehog^);

                EndTurnCleanup;

                FreeActionsList; // could send -left, -right and similar commands, so should be called before /nextturn

                ParseCommand('/nextturn', true);
                SwitchHedgehog;

                AfterSwitchHedgehog;
                bBetweenTurns:= false
                end;
            step:= Low(step)
            end;
    end
else if ((GameFlags and gfInfAttack) <> 0) then
    begin
    if delay2 = 0 then
        delay2:= cInactDelay * 50
    else
        begin
        dec(delay2);

        if ((delay2 mod cInactDelay) = 0) and (CurrentHedgehog <> nil) and (CurrentHedgehog^.Gear <> nil)
        and (not CurrentHedgehog^.Unplaced) then
            begin
            if (CurrentHedgehog^.Gear^.State and gstAttacked <> 0)
            and (Ammoz[CurrentHedgehog^.CurAmmoType].Ammo.Propz and ammoprop_NeedTarget <> 0) then
                begin
                CurrentHedgehog^.Gear^.State:= CurrentHedgehog^.Gear^.State or gstHHChooseTarget;
                isCursorVisible := true
                end;
            CurrentHedgehog^.Gear^.State:= CurrentHedgehog^.Gear^.State and (not gstAttacked);
            end;
        if delay2 = 0 then
            begin
            if (CurrentHedgehog^.Gear <> nil) and (CurrentHedgehog^.Gear^.State and gstAttacked = 0)
            and (CurAmmoGear = nil) then
                SweepDirty;
            CheckNoDamage;
            AliveCount:= 0; // shorter version of check for win to allow typical step activity to proceed
            for i:= 0 to Pred(ClansCount) do
                if ClansArray[i]^.ClanHealth > 0 then
                    inc(AliveCount);
            if (AliveCount <= 1) and ((GameFlags and gfOneClanMode) = 0) then
                begin
                step:= stChDmg;
                if TagTurnTimeLeft = 0 then
                    TagTurnTimeLeft:= TurnTimeLeft;
                TurnTimeLeft:= 0
                end
            end
        end
    end;

if TurnTimeLeft > 0 then
    if CurrentHedgehog^.Gear <> nil then
        if ((CurrentHedgehog^.Gear^.State and gstAttacking) = 0)
            and (not isInMultiShoot) then
                begin
                if (TurnTimeLeft = 5000)
                and (cHedgehogTurnTime >= 10000)
                and (not PlacingHogs)
                and (CurrentHedgehog^.Gear <> nil)
                and ((CurrentHedgehog^.Gear^.State and gstAttacked) = 0) then
                    PlaySoundV(sndHurry, CurrentTeam^.voicepack);
            if ReadyTimeLeft > 0 then
                begin
                if (ReadyTimeLeft = 2000) and (LastVoice.snd = sndNone) then
                    AddVoice(sndComeonthen, CurrentTeam^.voicepack);
                dec(ReadyTimeLeft)
                end
            else
                dec(TurnTimeLeft)
            end;

if skipFlag then
    begin
    if TagTurnTimeLeft = 0 then
        TagTurnTimeLeft:= TurnTimeLeft;
    TurnTimeLeft:= 0;
    skipFlag:= false;
    inc(CurrentHedgehog^.Team^.stats.TurnSkips);
    end;

if ((GameTicks and $FFFF) = $FFFF) then
    begin
    if (not CurrentTeam^.ExtDriven) then
        begin
        SendIPC(_S'#');
        AddFileLog('hiTicks increment message sent')
        end;

    if (not CurrentTeam^.ExtDriven) or CurrentTeam^.hasGone then
        inc(hiTicks) // we do not recieve a message for this
    end;
AddRandomness(CheckSum);
ScriptCall('onGameTick');
if GameTicks mod 20 = 0 then ScriptCall('onGameTick20');
inc(GameTicks)
end;

//Purpose, to reset all transient attributes toggled by a utility and clean up various gears and effects at end of turn
//If any of these are set as permanent toggles in the frontend, that needs to be checked and skipped here.
procedure EndTurnCleanup;
var  i: LongInt;
     t: PGear;
begin
    SpeechText:= ''; // in case it has not been consumed

    if (GameFlags and gfLowGravity) = 0 then
        begin
        cGravity:= cMaxWindSpeed * 2;
        cGravityf:= 0.00025 * 2
        end;

    if (GameFlags and gfVampiric) = 0 then
        cVampiric:= false;

    cDamageModifier:= _1;

    if (GameFlags and gfLaserSight) = 0 then
        cLaserSighting:= false;

    if (GameFlags and gfArtillery) = 0 then
        cArtillery:= false;
    // have to sweep *all* current team hedgehogs since it is theoretically possible if you have enough invulnerabilities and switch turns to make your entire team invulnerable
    if (CurrentTeam <> nil) then
        with CurrentTeam^ do
            for i:= 0 to cMaxHHIndex do
                with Hedgehogs[i] do
                    begin
(*
                    if (SpeechGear <> nil) then
                        begin
                        DeleteVisualGear(SpeechGear);  // remove to restore persisting beyond end of turn. Tiy says was too much of a gameplay issue
                        SpeechGear:= nil
                        end;
*)

                    if (Gear <> nil) then
                        begin
                        if (GameFlags and gfInvulnerable) = 0 then
                            Gear^.Invulnerable:= false;
                        end;
                    end;
    t:= GearsList;
    while t <> nil do
        begin
        t^.PortalCounter:= 0;
        if ((GameFlags and gfResetHealth) <> 0) and (t^.Kind = gtHedgehog) and (t^.Health < t^.Hedgehog^.InitialHealth) then
            begin
            t^.Health:= t^.Hedgehog^.InitialHealth;
            RenderHealth(t^.Hedgehog^);
            end;
        t:= t^.NextGear
        end;
   
    if ((GameFlags and gfResetWeps) <> 0) and (not PlacingHogs) then
        ResetWeapons;

    if (GameFlags and gfResetHealth) <> 0 then
        for i:= 0 to Pred(TeamsCount) do
            RecountTeamHealth(TeamsArray[i])
end;

procedure SetAllToActive;
var t: PGear;
begin
AllInactive:= false;
t:= GearsList;
while t <> nil do
    begin
    t^.Active:= true;
    t:= t^.NextGear
    end
end;

procedure SetAllHHToActive;
var t: PGear;
begin
AllInactive:= false;
t:= GearsList;
while t <> nil do
    begin
    if (t^.Kind = gtHedgehog) or (t^.Kind = gtExplosives) then
        t^.Active:= true;
    t:= t^.NextGear
    end
end;


procedure DrawGears;
var Gear: PGear;
    x, y: LongInt;
begin
Gear:= GearsList;
while Gear <> nil do
    begin
    if (Gear^.State and gstInvisible = 0) and (Gear^.Message and gmRemoveFromList = 0) then
        begin
        x:= hwRound(Gear^.X) + WorldDx;
        y:= hwRound(Gear^.Y) + WorldDy;
        RenderGear(Gear, x, y);
        end;
    Gear:= Gear^.NextGear
    end;
end;

procedure FreeGearsList;
var t, tt: PGear;
begin
    tt:= GearsList;
    GearsList:= nil;
    while tt <> nil do
    begin
        t:= tt;
        tt:= tt^.NextGear;
        Dispose(t)
    end;
end;

procedure AddMiscGears;
var i,rx, ry: Longword;
    rdx, rdy: hwFloat;
    Gear: PGear;
begin
AddGear(0, 0, gtATStartGame, 0, _0, _0, 2000);

i:= 0;
Gear:= PGear(1);
while (i < cLandMines) {and (Gear <> nil)} do // disable this check until better solution found
    begin
    Gear:= AddGear(0, 0, gtMine, 0, _0, _0, 0);
    FindPlace(Gear, false, 0, LAND_WIDTH);
    inc(i)
    end;

i:= 0;
Gear:= PGear(1);
while (i < cExplosives){ and (Gear <> nil)} do
    begin
    Gear:= AddGear(0, 0, gtExplosives, 0, _0, _0, 0);
    FindPlace(Gear, false, 0, LAND_WIDTH);
    inc(i)
    end;

if (GameFlags and gfLowGravity) <> 0 then
    begin
    cGravity:= cMaxWindSpeed;
    cGravityf:= 0.00025
    end;

if (GameFlags and gfVampiric) <> 0 then
    cVampiric:= true;

Gear:= GearsList;
if (GameFlags and gfInvulnerable) <> 0 then
    while Gear <> nil do
        begin
        Gear^.Invulnerable:= true;  // this is only checked on hogs right now, so no need for gear type check
        Gear:= Gear^.NextGear
        end;

if (GameFlags and gfLaserSight) <> 0 then
    cLaserSighting:= true;

if (GameFlags and gfArtillery) <> 0 then
    cArtillery:= true;
for i:= GetRandom(10)+30 downto 0 do
    begin
    rx:= GetRandom(rightX-leftX)+leftX;
    ry:= GetRandom(LAND_HEIGHT-topY)+topY;
    rdx:= _90-(GetRandomf*_360);
    rdy:= _90-(GetRandomf*_360);
    AddGear(rx, ry, gtGenericFaller, gstInvisible, rdx, rdy, $FFFFFFFF);
    end;

snowRight:= max(LAND_WIDTH,4096)+512;
snowLeft:= -(snowRight-LAND_WIDTH);

if not hasBorder and ((Theme = 'Snow') or (Theme = 'Christmas')) then
    for i:= vobCount * Longword(max(LAND_WIDTH,4096)) div 2048 downto 1 do
        AddGear(LongInt(GetRandom(snowRight - snowLeft)) + snowLeft, LongInt(LAND_HEIGHT + GetRandom(750)) - 1300, gtFlake, 0, _0, _0, 0);
end;


procedure ShotgunShot(Gear: PGear);
var t: PGear;
    dmg, r, dist: LongInt;
    dx, dy: hwFloat;
begin
Gear^.Radius:= cShotgunRadius;
t:= GearsList;
while t <> nil do
    begin
    case t^.Kind of
        gtHedgehog,
            gtMine,
            gtSMine,
            gtCase,
            gtTarget,
            gtExplosives,
            gtStructure: begin
//addFileLog('ShotgunShot radius: ' + inttostr(Gear^.Radius) + ', t^.Radius = ' + inttostr(t^.Radius) + ', distance = ' + inttostr(dist) + ', dmg = ' + inttostr(dmg));
                    dmg:= 0;
                    r:= Gear^.Radius + t^.Radius;
                    dx:= Gear^.X-t^.X;
                    dx.isNegative:= false;
                    dy:= Gear^.Y-t^.Y;
                    dy.isNegative:= false;
                    if r-hwRound(dx+dy) > 0 then
                        begin
                        dist:= hwRound(Distance(dx, dy));
                        dmg:= ModifyDamage(min(r - dist, 25), t);
                        end;
                    if dmg > 0 then
                        begin
                        if (not t^.Invulnerable) then
                            ApplyDamage(t, Gear^.Hedgehog, dmg, dsBullet)
                        else
                            Gear^.State:= Gear^.State or gstWinner;

                        DeleteCI(t);
                        t^.dX:= t^.dX + Gear^.dX * dmg * _0_01 + SignAs(cHHKick, Gear^.dX);
                        t^.dY:= t^.dY + Gear^.dY * dmg * _0_01;
                        t^.State:= t^.State or gstMoving;
                        t^.Active:= true;
                        FollowGear:= t
                        end
                    end;
            gtGrave: begin
                    dmg:= 0;
                    r:= Gear^.Radius + t^.Radius;
                    dx:= Gear^.X-t^.X;
                    dx.isNegative:= false;
                    dy:= Gear^.Y-t^.Y;
                    dy.isNegative:= false;
                    if r-hwRound(dx+dy) > 0 then
                        begin
                        dist:= hwRound(Distance(dx, dy));
                        dmg:= ModifyDamage(min(r - dist, 25), t);
                        end;
                    if dmg > 0 then
                        begin
                        t^.dY:= - _0_1;
                        t^.Active:= true
                        end
                    end;
        end;
    t:= t^.NextGear
    end;
if (GameFlags and gfSolidLand) = 0 then
    DrawExplosion(hwRound(Gear^.X), hwRound(Gear^.Y), cShotgunRadius)
end;

procedure AmmoShove(Ammo: PGear; Damage, Power: LongInt);
var t: PGearArray;
    Gear: PGear;
    i, tmpDmg: LongInt;
    VGear: PVisualGear;
begin
t:= CheckGearsCollision(Ammo);
// Just to avoid hogs on rope dodging fire.
if (CurAmmoGear <> nil) and ((CurAmmoGear^.Kind = gtRope) or (CurAmmoGear^.Kind = gtJetpack) or (CurAmmoGear^.Kind = gtBirdy))
and (CurrentHedgehog^.Gear <> nil) and (CurrentHedgehog^.Gear^.CollisionIndex = -1)
and (sqr(hwRound(Ammo^.X) - hwRound(CurrentHedgehog^.Gear^.X)) + sqr(hwRound(Ammo^.Y) - hwRound(CurrentHedgehog^.Gear^.Y)) <= sqr(cHHRadius + Ammo^.Radius)) then
    begin
    t^.ar[t^.Count]:= CurrentHedgehog^.Gear;
    inc(t^.Count)
    end;

i:= t^.Count;

if (Ammo^.Kind = gtFlame) and (i > 0) then
    Ammo^.Health:= 0;
while i > 0 do
    begin
    dec(i);
    Gear:= t^.ar[i];
    tmpDmg:= ModifyDamage(Damage, Gear);
    if (Gear^.State and gstNoDamage) = 0 then
        begin

        if (Ammo^.Kind = gtDEagleShot) or (Ammo^.Kind = gtSniperRifleShot) then 
            begin
            VGear := AddVisualGear(hwround(Ammo^.X), hwround(Ammo^.Y), vgtBulletHit);
            if VGear <> nil then
                VGear^.Angle := DxDy2Angle(-Ammo^.dX, Ammo^.dY);
            end;

        if (Gear^.Kind = gtHedgehog) and (Ammo^.State and gsttmpFlag <> 0) and (Ammo^.Kind = gtShover) then
            Gear^.FlightTime:= 1;

        case Gear^.Kind of
            gtHedgehog,
            gtMine,
            gtSMine,
            gtTarget,
            gtCase,
            gtExplosives,
            gtStructure:
            begin
            if (Ammo^.Kind = gtDrill) then
                begin
                Ammo^.Timer:= 0;
                exit;
                end;
            if (not Gear^.Invulnerable) then
                ApplyDamage(Gear, Ammo^.Hedgehog, tmpDmg, dsShove)
            else
                Gear^.State:= Gear^.State or gstWinner;
            if (Gear^.Kind = gtExplosives) and (Ammo^.Kind = gtBlowtorch) then 
                begin
                if (Ammo^.Hedgehog^.Gear <> nil) then
                    Ammo^.Hedgehog^.Gear^.State:= Ammo^.Hedgehog^.Gear^.State and (not gstNotKickable);
                ApplyDamage(Gear, Ammo^.Hedgehog, tmpDmg * 100, dsUnknown); // crank up damage for explosives + blowtorch
                end;

            DeleteCI(Gear);
            if (Gear^.Kind = gtHedgehog) and Gear^.Hedgehog^.King then
                begin
                Gear^.dX:= Ammo^.dX * Power * _0_005;
                Gear^.dY:= Ammo^.dY * Power * _0_005
                end
            else
                begin
                Gear^.dX:= Ammo^.dX * Power * _0_01;
                Gear^.dY:= Ammo^.dY * Power * _0_01
                end;

            Gear^.Active:= true;
            Gear^.State:= Gear^.State or gstMoving;

            // move the gear upwards a bit to throw it over tiny obstacles at start
            if TestCollisionXwithGear(Gear, hwSign(Gear^.dX)) then
                begin
                if not (TestCollisionXwithXYShift(Gear, _0, -3, hwSign(Gear^.dX))
                or (TestCollisionYwithGear(Gear, -1) <> 0)) then
                    Gear^.Y:= Gear^.Y - _1;
                if not (TestCollisionXwithXYShift(Gear, _0, -2, hwSign(Gear^.dX))
                or (TestCollisionYwithGear(Gear, -1) <> 0)) then
                    Gear^.Y:= Gear^.Y - _1;
                if not (TestCollisionXwithXYShift(Gear, _0, -1, hwSign(Gear^.dX))
                or (TestCollisionYwithGear(Gear, -1) <> 0)) then
                    Gear^.Y:= Gear^.Y - _1;
                end;

            if (Ammo^.Kind <> gtFlame) or ((Ammo^.State and gsttmpFlag) = 0) then
                FollowGear:= Gear
            end;
        end
        end;
    end;
if i <> 0 then
    SetAllToActive
end;

procedure AssignHHCoords;
var i, t, p, j: LongInt;
    ar: array[0..Pred(cMaxHHs)] of PHedgehog;
    Count: Longword;
begin
if (GameFlags and gfPlaceHog) <> 0 then
    PlacingHogs:= true;
if (GameFlags and gfDivideTeams) <> 0 then
    begin
    t:= 0;
    TryDo(ClansCount = 2, 'More or less than 2 clans on map in divided teams mode!', true);
    for p:= 0 to 1 do
        begin
        with ClansArray[p]^ do
            for j:= 0 to Pred(TeamsNumber) do
                with Teams[j]^ do
                    for i:= 0 to cMaxHHIndex do
                        with Hedgehogs[i] do
                            if (Gear <> nil) and (Gear^.X.QWordValue = 0) then
                                begin
                                if PlacingHogs then
                                    Unplaced:= true
                                else
                                    FindPlace(Gear, false, t, t + LAND_WIDTH div 2, true);// could make Gear == nil;
                                if Gear <> nil then
                                    begin
                                    Gear^.Pos:= GetRandom(49);
                                    Gear^.dX.isNegative:= p = 1;
                                    end
                                end;
        t:= LAND_WIDTH div 2
        end
    end else // mix hedgehogs
    begin
    Count:= 0;
    for p:= 0 to Pred(TeamsCount) do
        with TeamsArray[p]^ do
        begin
        for i:= 0 to cMaxHHIndex do
            with Hedgehogs[i] do
                if (Gear <> nil) and (Gear^.X.QWordValue = 0) then
                    begin
                    ar[Count]:= @Hedgehogs[i];
                    inc(Count)
                    end;
        end;
    // unC0Rr, while it is true user can watch value on map screen, IMO this (and check above) should be enforced in UI
    // - is there a good place to put values for the different widgets to check?  Right now they are kind of disconnected.
    //it would be nice if divide teams, forts mode and hh per map could all be checked by the team widget, or maybe disable start button
    TryDo(Count <= MaxHedgehogs, 'Too many hedgehogs for this map! (max # is ' + inttostr(MaxHedgehogs) + ')', true);
    while (Count > 0) do
        begin
        i:= GetRandom(Count);
        if PlacingHogs then
            ar[i]^.Unplaced:= true
        else
            FindPlace(ar[i]^.Gear, false, 0, LAND_WIDTH, true);
        if ar[i]^.Gear <> nil then
            begin
            ar[i]^.Gear^.dX.isNegative:= hwRound(ar[i]^.Gear^.X) > LAND_WIDTH div 2;
            ar[i]^.Gear^.Pos:= GetRandom(19)
            end;
        ar[i]:= ar[Count - 1];
        dec(Count)
        end
    end
end;

var GearsNearArray : TPGearArray;
function GearsNear(X, Y: hwFloat; Kind: TGearType; r: LongInt): PGearArrayS;
var
    t: PGear;
    s: Longword;
begin
    r:= r*r;
    s:= 0;
    SetLength(GearsNearArray, s);
    t := GearsList;
    while t <> nil do 
        begin
        if (t^.Kind = Kind) 
            and ((X - t^.X)*(X - t^.X) + (Y - t^.Y)*(Y-t^.Y) < int2hwFloat(r)) then
            begin
            inc(s);
            SetLength(GearsNearArray, s);
            GearsNearArray[s - 1] := t;
            end;
        t := t^.NextGear;
    end;

    GearsNear.size:= s;
    GearsNear.ar:= @GearsNearArray
end;

{procedure AmmoFlameWork(Ammo: PGear);
var t: PGear;
begin
t:= GearsList;
while t <> nil do
    begin
    if (t^.Kind = gtHedgehog) and (t^.Y < Ammo^.Y) then
        if not (hwSqr(Ammo^.X - t^.X) + hwSqr(Ammo^.Y - t^.Y - int2hwFloat(cHHRadius)) * 2 > _2) then
            begin
            ApplyDamage(t, 5);
            t^.dX:= t^.dX + (t^.X - Ammo^.X) * _0_02;
            t^.dY:= - _0_25;
            t^.Active:= true;
            DeleteCI(t);
            FollowGear:= t
            end;
    t:= t^.NextGear
    end;
end;}


function CountGears(Kind: TGearType): Longword;
var t: PGear;
    count: Longword = 0;
begin

t:= GearsList;
while t <> nil do
    begin
    if t^.Kind = Kind then
        inc(count);
    t:= t^.NextGear
    end;
CountGears:= count;
end;

function SpawnCustomCrateAt(x, y: LongInt; crate: TCrateType; content, cnt: Longword): PGear;
begin
    FollowGear := AddGear(x, y, gtCase, 0, _0, _0, 0);
    cCaseFactor := 0;

    if (crate <> HealthCrate) and (content > ord(High(TAmmoType))) then
        content := ord(High(TAmmoType));

    FollowGear^.Power:= cnt;

    case crate of
        HealthCrate:
            begin
            FollowGear^.Pos := posCaseHealth;
            FollowGear^.Health := content;
            AddCaption(GetEventString(eidNewHealthPack), cWhiteColor, capgrpAmmoInfo);
            end;
        AmmoCrate:
            begin
            FollowGear^.Pos := posCaseAmmo;
            FollowGear^.AmmoType := TAmmoType(content);
            AddCaption(GetEventString(eidNewAmmoPack), cWhiteColor, capgrpAmmoInfo);
            end;
        UtilityCrate:
            begin
            FollowGear^.Pos := posCaseUtility;
            FollowGear^.AmmoType := TAmmoType(content);
            AddCaption(GetEventString(eidNewUtilityPack), cWhiteColor, capgrpAmmoInfo);
            end;
    end;

    if ( (x = 0) and (y = 0) ) then
        FindPlace(FollowGear, true, 0, LAND_WIDTH);

    SpawnCustomCrateAt := FollowGear;
end;

function SpawnFakeCrateAt(x, y: LongInt; crate: TCrateType; explode: boolean; poison: boolean): PGear;
begin
    FollowGear := AddGear(x, y, gtCase, 0, _0, _0, 0);
    cCaseFactor := 0;
    FollowGear^.Pos := posCaseDummy;
    
    if explode then
        FollowGear^.Pos := FollowGear^.Pos + posCaseExplode;
    if poison then
        FollowGear^.Pos := FollowGear^.Pos + posCasePoison;

    case crate of
        HealthCrate:
            begin
            FollowGear^.Pos := FollowGear^.Pos + posCaseHealth;
            AddCaption(GetEventString(eidNewHealthPack), cWhiteColor, capgrpAmmoInfo);
            end;
        AmmoCrate:
            begin
            FollowGear^.Pos := FollowGear^.Pos + posCaseAmmo;
            AddCaption(GetEventString(eidNewAmmoPack), cWhiteColor, capgrpAmmoInfo);
            end;
        UtilityCrate:
            begin
            FollowGear^.Pos := FollowGear^.Pos + posCaseUtility;
            AddCaption(GetEventString(eidNewUtilityPack), cWhiteColor, capgrpAmmoInfo);
            end;
    end;

    if ( (x = 0) and (y = 0) ) then
        FindPlace(FollowGear, true, 0, LAND_WIDTH);

    SpawnFakeCrateAt := FollowGear;
end;

function GetAmmo(Hedgehog: PHedgehog): TAmmoType;
var t, aTot: LongInt;
    i: TAmmoType;
begin
Hedgehog:= Hedgehog; // avoid hint

aTot:= 0;
for i:= Low(TAmmoType) to High(TAmmoType) do
    if (Ammoz[i].Ammo.Propz and ammoprop_Utility) = 0 then
        inc(aTot, Ammoz[i].Probability);

t:= aTot;
i:= Low(TAmmoType);
if (t > 0) then
    begin
    t:= GetRandom(t);
    while t >= 0 do
        begin
        inc(i);
        if (Ammoz[i].Ammo.Propz and ammoprop_Utility) = 0 then
            dec(t, Ammoz[i].Probability)
        end
    end;
GetAmmo:= i
end;

function GetUtility(Hedgehog: PHedgehog): TAmmoType;
var t, uTot: LongInt;
    i: TAmmoType;
begin

uTot:= 0;
for i:= Low(TAmmoType) to High(TAmmoType) do
    if ((Ammoz[i].Ammo.Propz and ammoprop_Utility) <> 0)
    and ((Hedgehog^.Team^.HedgehogsNumber > 1) or (Ammoz[i].Ammo.AmmoType <> amSwitch)) then
        inc(uTot, Ammoz[i].Probability);

t:= uTot;
i:= Low(TAmmoType);
if (t > 0) then
    begin
    t:= GetRandom(t);
    while t >= 0 do
        begin
        inc(i);
        if ((Ammoz[i].Ammo.Propz and ammoprop_Utility) <> 0) and ((Hedgehog^.Team^.HedgehogsNumber > 1)
        or (Ammoz[i].Ammo.AmmoType <> amSwitch)) then
            dec(t, Ammoz[i].Probability)
        end
    end;
GetUtility:= i
end;



procedure SpawnBoxOfSmth;
var t, aTot, uTot, a, h: LongInt;
    i: TAmmoType;
begin
if (PlacingHogs) or
    (cCaseFactor = 0)
    or (CountGears(gtCase) >= 5)
    or (GetRandom(cCaseFactor) <> 0) then
       exit;

FollowGear:= nil;
aTot:= 0;
uTot:= 0;
for i:= Low(TAmmoType) to High(TAmmoType) do
    if (Ammoz[i].Ammo.Propz and ammoprop_Utility) = 0 then
        inc(aTot, Ammoz[i].Probability)
    else
        inc(uTot, Ammoz[i].Probability);

t:=0;
a:=aTot;
h:= 1;

if (aTot+uTot) <> 0 then
    if ((GameFlags and gfInvulnerable) = 0) then
        begin
        h:= cHealthCaseProb * 100;
        t:= GetRandom(10000);
        a:= (10000-h)*aTot div (aTot+uTot)
        end
    else
        begin
        t:= GetRandom(aTot+uTot);
        h:= 0
        end;


if t<h then
    begin
    FollowGear:= AddGear(0, 0, gtCase, 0, _0, _0, 0);
    FollowGear^.Health:= cHealthCaseAmount;
    FollowGear^.Pos:= posCaseHealth;
    AddCaption(GetEventString(eidNewHealthPack), cWhiteColor, capgrpAmmoInfo);
    end
else if (t<a+h) then
    begin
    t:= aTot;
    if (t > 0) then
        begin
        FollowGear:= AddGear(0, 0, gtCase, 0, _0, _0, 0);
        t:= GetRandom(t);
        i:= Low(TAmmoType);
        FollowGear^.Pos:= posCaseAmmo;
        FollowGear^.AmmoType:= i;
        AddCaption(GetEventString(eidNewAmmoPack), cWhiteColor, capgrpAmmoInfo);
        end
    end
else
    begin
    t:= uTot;
    if (t > 0) then
        begin
        FollowGear:= AddGear(0, 0, gtCase, 0, _0, _0, 0);
        t:= GetRandom(t);
        i:= Low(TAmmoType);
        FollowGear^.Pos:= posCaseUtility;
        FollowGear^.AmmoType:= i;
        AddCaption(GetEventString(eidNewUtilityPack), cWhiteColor, capgrpAmmoInfo);
        end
    end;

// handles case of no ammo or utility crates - considered also placing booleans in uAmmos and altering probabilities
if (FollowGear <> nil) then
    begin
    FindPlace(FollowGear, true, 0, LAND_WIDTH);

    if (FollowGear <> nil) then
        AddVoice(sndReinforce, CurrentTeam^.voicepack)
    end
end;


function GearByUID(uid : Longword) : PGear;
var gear: PGear;
begin
GearByUID:= nil;
if uid = 0 then exit;
if (lastGearByUID <> nil) and (lastGearByUID^.uid = uid) then
    begin
    GearByUID:= lastGearByUID;
    exit
    end;
gear:= GearsList;
while gear <> nil do
    begin
    if gear^.uid = uid then
        begin
        lastGearByUID:= gear;
        GearByUID:= gear;
        exit
        end;
    gear:= gear^.NextGear
    end
end;


procedure chSkip(var s: shortstring);
begin
s:= s; // avoid compiler hint
if not CurrentTeam^.ExtDriven then
    SendIPC(_S',');
uStats.Skipped;
skipFlag:= true
end;

procedure chHogSay(var s: shortstring);
var Gear: PVisualGear;
    text: shortstring;
    hh: PHedgehog;
    i, x, t, h: byte;
    c, j: LongInt;
begin
    hh:= nil;
    i:= 0;
    t:= 0;
    x:= byte(s[1]);  // speech type
    if x < 4 then
        begin
        t:= byte(s[2]);  // team
        if Length(s) > 2 then
            h:= byte(s[3])  // target hog
        end;
    // allow targetting a hog by specifying a number as the first portion of the text
    if (x < 4) and (h > byte('0')) and (h < byte('9')) then
        i:= h - 48;
    if i <> 0 then
        text:= copy(s, 4, Length(s) - 1)
    else if x < 4 then
        text:= copy(s, 3, Length(s) - 1)
    else text:= copy(s, 2, Length(s) - 1);

    (*
    if CheckNoTeamOrHH then
        begin
        ParseCommand('say ' + text, true);
        exit
        end;
    *)

    if (x < 4) and (TeamsArray[t] <> nil) then
        begin
            // if team matches current hedgehog team, default to current hedgehog
            if (i = 0) and (CurrentHedgehog <> nil) and (CurrentHedgehog^.Team = TeamsArray[t]) then
                hh:= CurrentHedgehog
            else 
                begin
            // otherwise use the first living hog or the hog amongs the remaining ones indicated by i
                j:= 0;
                c:= 0;
                while (j <= cMaxHHIndex) and (hh = nil) do
                    begin
                    if (TeamsArray[t]^.Hedgehogs[j].Gear <> nil) then
                        begin
                        inc(c);
                        if (i=0) or (i=c) then
                            hh:= @TeamsArray[t]^.Hedgehogs[j]
                        end;
                    inc(j)
                    end
                end;
        if hh <> nil then 
            begin
            Gear:= AddVisualGear(0, 0, vgtSpeechBubble);
            if Gear <> nil then
                begin
                Gear^.Hedgehog:= hh;
                Gear^.Text:= text;
                Gear^.FrameTicks:= x
                end
            end
        //else ParseCommand('say ' + text, true)
        end
    else if (x >= 4) then
        begin
        SpeechType:= x-3;
        SpeechText:= text
        end;
end;

procedure initModule;
const handlers: array[TGearType] of TGearStepProcedure = (
            @doStepFlame,
            @doStepHedgehog,
            @doStepMine,
            @doStepCase,
            @doStepCase,
            @doStepBomb,
            @doStepShell,
            @doStepGrave,
            @doStepBee,
            @doStepShotgunShot,
            @doStepPickHammer,
            @doStepRope,
            @doStepDEagleShot,
            @doStepDynamite,
            @doStepBomb,
            @doStepCluster,
            @doStepShover,
            @doStepFirePunch,
            @doStepActionTimer,
            @doStepActionTimer,
            @doStepParachute,
            @doStepAirAttack,
            @doStepAirBomb,
            @doStepBlowTorch,
            @doStepGirder,
            @doStepTeleport,
            @doStepSwitcher,
            @doStepTarget,
            @doStepMortar,
            @doStepWhip,
            @doStepKamikaze,
            @doStepCake,
            @doStepSeduction,
            @doStepBomb,
            @doStepCluster,
            @doStepBomb,
            @doStepWaterUp,
            @doStepDrill,
            @doStepBallgun,
            @doStepBomb,
            @doStepRCPlane,
            @doStepSniperRifleShot,
            @doStepJetpack,
            @doStepMolotov,
            @doStepBirdy,
            @doStepEggWork,
            @doStepPortalShot,
            @doStepPiano,
            @doStepBomb,
            @doStepSineGunShot,
            @doStepFlamethrower,
            @doStepSMine,
            @doStepPoisonCloud,
            @doStepHammer,
            @doStepHammerHit,
            @doStepResurrector,
            @doStepNapalmBomb,
            @doStepSnowball,
            @doStepSnowflake,
            @doStepStructure,
            @doStepLandGun,
            @doStepTardis,
            @doStepIceGun,
            @doStepAddAmmo,
            @doStepGenericFaller,
            @doStepKnife);
begin
    doStepHandlers:= handlers;

    RegisterVariable('skip', @chSkip, false);
    RegisterVariable('hogsay', @chHogSay, true );

    CurAmmoGear:= nil;
    GearsList:= nil;
    curHandledGear:= nil;

    KilledHHs:= 0;
    SuddenDeath:= false;
    SuddenDeathDmg:= false;
    SpeechType:= 1;
    skipFlag:= false;

    AllInactive:= false;
    PrvInactive:= false;

    //typed const
    delay:= 0;
    delay2:= 0;
    step:= stDelay;
    upd:= 0;

    //SDMusic:= 'hell.ogg';
end;

procedure freeModule;
begin
    FreeGearsList();
end;

end.