1 (*

     2  * Hedgewars, a worms-like game

     3  * Copyright (c) 2006 Andrey Korotaev <unC0Rr@gmail.com>

     4  *

     5  * This program is free software; you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation; version 2 of the License

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program; if not, write to the Free Software

    16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA

    17  *)

    18 

    19 unit uAIThinkStack;

    20 interface

    21 uses uAIActions, uGears, uFloat;

    22 {$INCLUDE options.inc}

    23 const cBranchStackSize = 12;

    24 type TStackEntry = record

    25                    WastedTicks: Longword;

    26                    MadeActions: TActions;

    27                    Hedgehog: TGear;

    28                    end;

    29 

    30 var ThinkStack: record

    31                 Count: Longword;

    32                 States: array[0..Pred(cBranchStackSize)] of TStackEntry;

    33                 end;

    34 

    35 function  Push(Ticks: Longword; const Actions: TActions; const Me: TGear; Dir: LongInt): boolean;

    36 function  Pop(var Ticks: Longword; var Actions: TActions; var Me: TGear): boolean;

    37 function  PosInThinkStack(Me: PGear): boolean;

    38 procedure ClearThinkStack;

    39 

    40 implementation

    41 

    42 function Push(Ticks: Longword; const Actions: TActions; const Me: TGear; Dir: LongInt): boolean;

    43 var Result: boolean;

    44 begin

    45 Result:= (ThinkStack.Count < cBranchStackSize) and (Actions.Count < MAXACTIONS - 5);

    46 if Result then

    47    with ThinkStack.States[ThinkStack.Count] do

    48         begin

    49         WastedTicks:= Ticks;

    50         MadeActions:= Actions;

    51         Hedgehog:= Me;

    52         Hedgehog.Message:= Dir;

    53         inc(ThinkStack.Count)

    54         end;

    55 Push:= Result

    56 end;

    57 

    58 function  Pop(var Ticks: Longword; var Actions: TActions; var Me: TGear): boolean;

    59 var Result: boolean;

    60 begin

    61 Result:= ThinkStack.Count > 0;

    62 if Result then

    63    begin

    64    dec(ThinkStack.Count);

    65    with ThinkStack.States[ThinkStack.Count] do

    66         begin

    67         Ticks:= WastedTicks;

    68         Actions:= MadeActions;

    69         Me:= Hedgehog

    70         end

    71    end;

    72 Pop:= Result

    73 end;

    74 

    75 function PosInThinkStack(Me: PGear): boolean;

    76 var i: Longword;

    77 begin

    78 i:= 0;

    79 while (i < ThinkStack.Count) do

    80       begin

    81       if (not (2 < hwAbs(ThinkStack.States[i].Hedgehog.X - Me^.X) +

    82                    hwAbs(ThinkStack.States[i].Hedgehog.Y - Me^.Y)))

    83           and (ThinkStack.States[i].Hedgehog.Message = Me^.Message) then exit(true);

    84       inc(i)

    85       end;

    86 PosInThinkStack:= false

    87 end;

    88 

    89 procedure ClearThinkStack;

    90 begin

    91 ThinkStack.Count:= 0

    92 end;

    93 

    94 end.