(*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2005-2008 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

 *)

unit uCollisions;

interface

uses uGears, uFloat;

{$INCLUDE options.inc}

const cMaxGearArrayInd = 255;

type PGearArray = ^TGearArray;

	TGearArray = record

			ar: array[0..cMaxGearArrayInd] of PGear;

			Count: Longword

			end;

procedure AddGearCI(Gear: PGear);

procedure DeleteCI(Gear: PGear);

function CheckGearsCollision(Gear: PGear): PGearArray;

function TestCollisionXwithGear(Gear: PGear; Dir: LongInt): boolean;

function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): boolean;

function TestCollisionXKick(Gear: PGear; Dir: LongInt): boolean;

function TestCollisionYKick(Gear: PGear; Dir: LongInt): boolean;

function TestCollisionY(Gear: PGear; Dir: LongInt): boolean;

function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt): boolean;

function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt): boolean;

implementation

uses uMisc, uConsts, uLand, uLandGraphics, uConsole;

type TCollisionEntry = record

			X, Y, Radius: LongInt;

			cGear: PGear;

			end;

const MAXRECTSINDEX = 511;

var Count: Longword = 0;

	cinfos: array[0..MAXRECTSINDEX] of TCollisionEntry;

	ga: TGearArray;

procedure AddGearCI(Gear: PGear);

begin

if Gear^.CollisionIndex >= 0 then exit;

TryDo(Count <= MAXRECTSINDEX, 'Collision rects array overflow', true);

with cinfos[Count] do

	begin

	X:= hwRound(Gear^.X);

	Y:= hwRound(Gear^.Y);

	Radius:= Gear^.Radius;

	ChangeRoundInLand(X, Y, Radius - 1, true);

	cGear:= Gear

	end;

Gear^.CollisionIndex:= Count;

inc(Count)

end;

procedure DeleteCI(Gear: PGear);

begin

if Gear^.CollisionIndex >= 0 then

	begin

	with cinfos[Gear^.CollisionIndex] do

		ChangeRoundInLand(X, Y, Radius - 1, false);

	cinfos[Gear^.CollisionIndex]:= cinfos[Pred(Count)];

	cinfos[Gear^.CollisionIndex].cGear^.CollisionIndex:= Gear^.CollisionIndex;

	Gear^.CollisionIndex:= -1;

	dec(Count)

	end;

end;

function CheckGearsCollision(Gear: PGear): PGearArray;

var mx, my: LongInt;

	i: Longword;

begin

CheckGearsCollision:= @ga;

ga.Count:= 0;

if Count = 0 then exit;

mx:= hwRound(Gear^.X);

my:= hwRound(Gear^.Y);

for i:= 0 to Pred(Count) do

	with cinfos[i] do

		if (Gear <> cGear) and

			(sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius)) then

				begin

				ga.ar[ga.Count]:= cinfos[i].cGear;

				inc(ga.Count)

				end

end;

function TestCollisionXwithGear(Gear: PGear; Dir: LongInt): boolean;

var x, y, i: LongInt;

	TestWord: LongWord;

begin

if Gear^.IntersectGear <> nil then

   with Gear^ do

        if (hwRound(IntersectGear^.X) + IntersectGear^.Radius < hwRound(X) - Radius) or

           (hwRound(IntersectGear^.X) - IntersectGear^.Radius > hwRound(X) + Radius) then

           begin

           IntersectGear:= nil;

           TestWord:= 0

           end else

           TestWord:= 255

   else TestWord:= 0;

x:= hwRound(Gear^.X);

if Dir < 0 then x:= x - Gear^.Radius

           else x:= x + Gear^.Radius;

if (x and LAND_WIDTH_MASK) = 0 then

   begin

   y:= hwRound(Gear^.Y) - Gear^.Radius + 1;

   i:= y + Gear^.Radius * 2 - 2;

   repeat

     if (y and LAND_HEIGHT_MASK) = 0 then

        if Land[y, x] > TestWord then exit(true);

     inc(y)

   until (y > i);

   end;

TestCollisionXwithGear:= false

end;

function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): boolean;

var x, y, i: LongInt;

    TestWord: LongWord;

begin

if Gear^.IntersectGear <> nil then

   with Gear^ do

        if (hwRound(IntersectGear^.Y) + IntersectGear^.Radius < hwRound(Y) - Radius) or

           (hwRound(IntersectGear^.Y) - IntersectGear^.Radius > hwRound(Y) + Radius) then

           begin

           IntersectGear:= nil;

           TestWord:= 0

           end else

           TestWord:= 255

   else TestWord:= 0;

y:= hwRound(Gear^.Y);

if Dir < 0 then y:= y - Gear^.Radius

           else y:= y + Gear^.Radius;

if (y and LAND_HEIGHT_MASK) = 0 then

   begin

   x:= hwRound(Gear^.X) - Gear^.Radius + 1;

   i:= x + Gear^.Radius * 2 - 2;

   repeat

     if (x and LAND_WIDTH_MASK) = 0 then

        if Land[y, x] > TestWord then exit(true);

     inc(x)

   until (x > i);

   end;

TestCollisionYwithGear:= false

end;

function TestCollisionXKick(Gear: PGear; Dir: LongInt): boolean;

var x, y, mx, my, i: LongInt;

    flag: boolean;

begin

flag:= false;

x:= hwRound(Gear^.X);

if Dir < 0 then x:= x - Gear^.Radius

           else x:= x + Gear^.Radius;

if (x and LAND_WIDTH_MASK) = 0 then

   begin

   y:= hwRound(Gear^.Y) - Gear^.Radius + 1;

   i:= y + Gear^.Radius * 2 - 2;

   repeat

     if (y and LAND_HEIGHT_MASK) = 0 then

           if Land[y, x] > 255 then exit(true)

           else if Land[y, x] <> 0 then flag:= true;

     inc(y)

   until (y > i);

   end;

TestCollisionXKick:= flag;

if flag then

   begin

   if hwAbs(Gear^.dX) < cHHKick then exit;

   if (Gear^.State and gstHHJumping <> 0)

   and (hwAbs(Gear^.dX) < _0_4) then exit;

   mx:= hwRound(Gear^.X);

   my:= hwRound(Gear^.Y);

   for i:= 0 to Pred(Count) do

    with cinfos[i] do

      if (Gear <> cGear) and

         (sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) and

         ((mx > x) xor (Dir > 0)) then

         if (cGear^.Kind in [gtHedgehog, gtMine]) and ((Gear^.State and gstNotKickable) = 0) then

             begin

             with cGear^ do

                  begin

                  dX:= Gear^.dX;

                  dY:= Gear^.dY * _0_5;

                  State:= State or gstMoving;

                  Active:= true

                  end;

             DeleteCI(cGear);

             exit(false)

             end

   end

end;

function TestCollisionYKick(Gear: PGear; Dir: LongInt): boolean;

var x, y, mx, my, i: LongInt;

    flag: boolean;

begin

flag:= false;

y:= hwRound(Gear^.Y);

if Dir < 0 then y:= y - Gear^.Radius

           else y:= y + Gear^.Radius;

if (y and LAND_HEIGHT_MASK) = 0 then

   begin

   x:= hwRound(Gear^.X) - Gear^.Radius + 1;

   i:= x + Gear^.Radius * 2 - 2;

   repeat

     if (x and LAND_WIDTH_MASK) = 0 then

        if Land[y, x] > 0 then

           if Land[y, x] > 255 then exit(true)

           else if Land[y, x] <> 0 then flag:= true;

     inc(x)

   until (x > i);

   end;

TestCollisionYKick:= flag;

if flag then

   begin

   if hwAbs(Gear^.dY) < cHHKick then exit(true);

   if (Gear^.State and gstHHJumping <> 0)

   and (not Gear^.dY.isNegative)

   and (Gear^.dY < _0_4) then exit;

   mx:= hwRound(Gear^.X);

   my:= hwRound(Gear^.Y);

   for i:= 0 to Pred(Count) do

    with cinfos[i] do

      if (Gear <> cGear) and

         (sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) and

         ((my > y) xor (Dir > 0)) then

         if (cGear^.Kind in [gtHedgehog, gtMine]) and ((Gear^.State and gstNotKickable) = 0) then

             begin

             with cGear^ do

                  begin

                  dX:= Gear^.dX * _0_5;

                  dY:= Gear^.dY;

                  State:= State or gstMoving;

                  Active:= true

                  end;

             DeleteCI(cGear);

             exit(false)

             end

   end

end;

function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt): boolean;

begin

Gear^.X:= Gear^.X + ShiftX;

Gear^.Y:= Gear^.Y + int2hwFloat(ShiftY);

TestCollisionXwithXYShift:= TestCollisionXwithGear(Gear, Dir);

Gear^.X:= Gear^.X - ShiftX;

Gear^.Y:= Gear^.Y - int2hwFloat(ShiftY)

end;

function TestCollisionY(Gear: PGear; Dir: LongInt): boolean;

var x, y, i: LongInt;

begin

y:= hwRound(Gear^.Y);

if Dir < 0 then y:= y - Gear^.Radius

           else y:= y + Gear^.Radius;

if (y and LAND_HEIGHT_MASK) = 0 then

   begin

   x:= hwRound(Gear^.X) - Gear^.Radius + 1;

   i:= x + Gear^.Radius * 2 - 2;

   repeat

     if (x and LAND_WIDTH_MASK) = 0 then

        if Land[y, x] > 255 then exit(true);

     inc(x)

   until (x > i);

   end;

TestCollisionY:= false

end;

function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt): boolean;

begin

Gear^.X:= Gear^.X + int2hwFloat(ShiftX);

Gear^.Y:= Gear^.Y + int2hwFloat(ShiftY);

TestCollisionYwithXYShift:= TestCollisionYwithGear(Gear, Dir);

Gear^.X:= Gear^.X - int2hwFloat(ShiftX);

Gear^.Y:= Gear^.Y - int2hwFloat(ShiftY)

end;

end.