(*

 * 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 uGearsHandlersRope;

interface

uses uTypes;

procedure doStepRope(Gear: PGear);

implementation

uses uConsts, uFloat, uCollisions, uVariables, uGearsList, uSound, uGearsUtils,

    uAmmos, uDebug, uUtils, uGearsHedgehog, uGearsRender;

procedure doStepRopeAfterAttack(Gear: PGear);

var 

    HHGear: PGear;

begin

    HHGear := Gear^.Hedgehog^.Gear;

    if ((HHGear^.State and gstHHDriven) = 0)

    or (CheckGearDrowning(HHGear))

    or (TestCollisionYwithGear(HHGear, 1) <> 0) then

        begin

        DeleteGear(Gear);

        isCursorVisible := false;

        ApplyAmmoChanges(HHGear^.Hedgehog^);

        exit

        end;

    HedgehogChAngle(HHGear);

    if TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) then

        SetLittle(HHGear^.dX);

    if HHGear^.dY.isNegative and (TestCollisionYwithGear(HHGear, -1) <> 0) then

        HHGear^.dY := _0;

    HHGear^.X := HHGear^.X + HHGear^.dX;

    HHGear^.Y := HHGear^.Y + HHGear^.dY;

    HHGear^.dY := HHGear^.dY + cGravity;

    if (GameFlags and gfMoreWind) <> 0 then

        HHGear^.dX := HHGear^.dX + cWindSpeed / HHGear^.Density;

    if (Gear^.Message and gmAttack) <> 0 then

        begin

        Gear^.X := HHGear^.X;

        Gear^.Y := HHGear^.Y;

        ApplyAngleBounds(Gear^.Hedgehog^, amRope);

        Gear^.dX := SignAs(AngleSin(HHGear^.Angle), HHGear^.dX);

        Gear^.dY := -AngleCos(HHGear^.Angle);

        Gear^.Friction := _4_5 * cRopePercent;

        Gear^.Elasticity := _0;

        Gear^.State := Gear^.State and (not gsttmpflag);

        Gear^.doStep := @doStepRope;

        end

end;

procedure RopeDeleteMe(Gear, HHGear: PGear);

begin

    PlaySound(sndRopeRelease);

    HHGear^.dX.QWordValue:= HHGear^.dX.QWordValue div Gear^.stepFreq;

    HHGear^.dY.QWordValue:= HHGear^.dY.QWordValue div Gear^.stepFreq;

    with HHGear^ do

        begin

        Message := Message and (not gmAttack);

        State := (State or gstMoving) and (not gstWinner);

        end;

    DeleteGear(Gear)

end;

procedure RopeWaitCollision(Gear, HHGear: PGear);

begin

    PlaySound(sndRopeRelease);

    with HHGear^ do

        begin

        Message := Message and (not gmAttack);

        State := State or gstMoving;

        end;

    RopePoints.Count := 0;

    Gear^.Elasticity := _0;

    Gear^.doStep := @doStepRopeAfterAttack;

    HHGear^.dX.QWordValue:= HHGear^.dX.QWordValue div Gear^.stepFreq;

    HHGear^.dY.QWordValue:= HHGear^.dY.QWordValue div Gear^.stepFreq;

    Gear^.stepFreq := 1

end;

procedure doStepRopeWork(Gear: PGear);

var 

    HHGear: PGear;

    len, tx, ty, nx, ny, ropeDx, ropeDy, mdX, mdY, t: hwFloat;

    lx, ly, cd, i: LongInt;

    haveCollision,

    haveDivided: boolean;

begin

    if GameTicks mod 8 <> 0 then exit;

    HHGear := Gear^.Hedgehog^.Gear;

    haveCollision:= false;

    if (Gear^.Message and gmLeft  <> 0) and (not TestCollisionXwithGear(HHGear, -1)) then

        HHGear^.dX := HHGear^.dX - _0_0128

    else haveCollision:= true;

    if (Gear^.Message and gmRight <> 0) and (not TestCollisionXwithGear(HHGear,  1)) then

        HHGear^.dX := HHGear^.dX + _0_0128

    else haveCollision:= true;

    if ((HHGear^.State and gstHHDriven) = 0)

       or (CheckGearDrowning(HHGear)) or (Gear^.PortalCounter <> 0) then

        begin

        RopeDeleteMe(Gear, HHGear);

        exit

        end;

    // vector between hedgehog and rope attaching point

    ropeDx := HHGear^.X - Gear^.X;

    ropeDy := HHGear^.Y - Gear^.Y;

    if TestCollisionYwithGear(HHGear, 1) = 0 then

        begin

        // depending on the rope vector we know which X-side to check for collision

        // in order to find out if the hog can still be moved by gravity

        if ropeDx.isNegative = RopeDy.IsNegative then

            cd:= -1

        else

            cd:= 1;

        // apply gravity if there is no obstacle

        if not TestCollisionXwithGear(HHGear, cd) then

            HHGear^.dY := HHGear^.dY + cGravity * 64;

        if (GameFlags and gfMoreWind) <> 0 then

            // apply wind if there's no obstacle

            if not TestCollisionXwithGear(HHGear, hwSign(cWindSpeed)) then

                HHGear^.dX := HHGear^.dX + cWindSpeed * 64 / HHGear^.Density;

        end

    else haveCollision:= true;

    if ((Gear^.Message and gmDown) <> 0) and (Gear^.Elasticity < Gear^.Friction) then

        if not (TestCollisionXwithGear(HHGear, hwSign(ropeDx))

        or (TestCollisionYwithGear(HHGear, hwSign(ropeDy)) <> 0)) then

            Gear^.Elasticity := Gear^.Elasticity + _2_4

    else haveCollision:= true;

    if ((Gear^.Message and gmUp) <> 0) and (Gear^.Elasticity > _30) then

        if not (TestCollisionXwithGear(HHGear, -hwSign(ropeDx))

        or (TestCollisionYwithGear(HHGear, -hwSign(ropeDy)) <> 0)) then

            Gear^.Elasticity := Gear^.Elasticity - _2_4

    else haveCollision:= true;

(*

I am not so sure this is useful. Disabling

    if haveCollision then

        begin

        if TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) and not TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) then

            HHGear^.dX.isNegative:= not HHGear^.dX.isNegative;

        if (TestCollisionYwithGear(HHGear, hwSign(HHGear^.dY)) <> 0) and (TestCollisionYwithGear(HHGear, -hwSign(HHGear^.dY)) = 0) then

            HHGear^.dY.isNegative:= not HHGear^.dY.isNegative;

        end;

*)

    mdX := ropeDx + HHGear^.dX;

    mdY := ropeDy + HHGear^.dY;

    len := _1 / Distance(mdX, mdY);

    // rope vector plus hedgehog direction vector normalized

    mdX := mdX * len;

    mdY := mdY * len;

    // for visual purposes only

    Gear^.dX := mdX;

    Gear^.dY := mdY;

    /////

    tx := HHGear^.X;

    ty := HHGear^.Y;

    HHGear^.X := Gear^.X + mdX * Gear^.Elasticity;

    HHGear^.Y := Gear^.Y + mdY * Gear^.Elasticity;

    HHGear^.dX := HHGear^.X - tx;

    HHGear^.dY := HHGear^.Y - ty;

    ////

    haveDivided := false;

    // check whether rope needs dividing

    len := Gear^.Elasticity - _5;

    nx := Gear^.X + mdX * len;

    ny := Gear^.Y + mdY * len;

    tx := mdX * _2_4; // should be the same as increase step

    ty := mdY * _2_4;

    while len > _3 do

        begin

        lx := hwRound(nx);

        ly := hwRound(ny);

        if ((ly and LAND_HEIGHT_MASK) = 0) and ((lx and LAND_WIDTH_MASK) = 0) and ((Land[ly, lx] and $FF00) <> 0) then

            begin

            ny := _1 / Distance(ropeDx, ropeDy);

            // old rope pos

            nx := ropeDx * ny;

            ny := ropeDy * ny;

            with RopePoints.ar[RopePoints.Count] do

                begin

                X := Gear^.X;

                Y := Gear^.Y;

                if RopePoints.Count = 0 then

                    RopePoints.HookAngle := DxDy2Angle(Gear^.dY, Gear^.dX);

                b := (nx * HHGear^.dY) > (ny * HHGear^.dX);

                dLen := len

                end;

            with RopePoints.rounded[RopePoints.Count] do

                begin

                X := hwRound(Gear^.X);

                Y := hwRound(Gear^.Y);

                end;

            Gear^.X := Gear^.X + nx * len;

            Gear^.Y := Gear^.Y + ny * len;

            inc(RopePoints.Count);

            TryDo(RopePoints.Count <= MAXROPEPOINTS, 'Rope points overflow', true);

            Gear^.Elasticity := Gear^.Elasticity - len;

            Gear^.Friction := Gear^.Friction - len;

            haveDivided := true;

            break

            end;

        nx := nx - tx;

        ny := ny - ty;

        // len := len - _2_4 // should be the same as increase step

        len.QWordValue := len.QWordValue - _2_4.QWordValue;

        end;

    if not haveDivided then

        if RopePoints.Count > 0 then // check whether the last dividing point could be removed

            begin

            tx := RopePoints.ar[Pred(RopePoints.Count)].X;

            ty := RopePoints.ar[Pred(RopePoints.Count)].Y;

            mdX := tx - Gear^.X;

            mdY := ty - Gear^.Y;

            if RopePoints.ar[Pred(RopePoints.Count)].b xor (mdX * (ty - HHGear^.Y) > (tx - HHGear^.X) * mdY) then

                begin

                dec(RopePoints.Count);

                Gear^.X := RopePoints.ar[RopePoints.Count].X;

                Gear^.Y := RopePoints.ar[RopePoints.Count].Y;

                Gear^.Elasticity := Gear^.Elasticity + RopePoints.ar[RopePoints.Count].dLen;

                Gear^.Friction := Gear^.Friction + RopePoints.ar[RopePoints.Count].dLen;

                // restore hog position

                len := _1 / Distance(mdX, mdY);

                mdX := mdX * len;

                mdY := mdY * len;

                HHGear^.X := Gear^.X - mdX * Gear^.Elasticity;

                HHGear^.Y := Gear^.Y - mdY * Gear^.Elasticity;

                end

            end;

    haveCollision := false;

    if TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) then

        begin

        HHGear^.dX := -_0_6 * HHGear^.dX;

        haveCollision := true

        end;

    if TestCollisionYwithGear(HHGear, hwSign(HHGear^.dY)) <> 0 then

        begin

        HHGear^.dY := -_0_6 * HHGear^.dY;

        haveCollision := true

        end;

    if haveCollision and (Gear^.Message and (gmLeft or gmRight) <> 0) and (Gear^.Message and (gmUp or gmDown) <> 0) then

        begin

        HHGear^.dX := SignAs(hwAbs(HHGear^.dX) + _1_6, HHGear^.dX);

        HHGear^.dY := SignAs(hwAbs(HHGear^.dY) + _1_6, HHGear^.dY)

        end;

    len := hwSqr(HHGear^.dX) + hwSqr(HHGear^.dY);

    if len > _49 then

        begin

        len := _7 / hwSqrt(len);

        HHGear^.dX := HHGear^.dX * len;

        HHGear^.dY := HHGear^.dY * len;

        end;

    haveCollision:= ((hwRound(Gear^.Y) and LAND_HEIGHT_MASK) = 0) and ((hwRound(Gear^.X) and LAND_WIDTH_MASK) = 0) and ((Land[hwRound(Gear^.Y), hwRound(Gear^.X)]) <> 0);

    if not haveCollision then

        begin

        // backup gear location

        tx:= Gear^.X;

        ty:= Gear^.Y;

        if RopePoints.Count > 0 then

            begin

            // set gear location to the remote end of the rope, the attachment point

            Gear^.X:= RopePoints.ar[0].X;

            Gear^.Y:= RopePoints.ar[0].Y;

            end;

        CheckCollision(Gear);

        // if we haven't found any collision yet then check the other side too

        if (Gear^.State and gstCollision) = 0 then

            begin

            Gear^.dX.isNegative:= not Gear^.dX.isNegative;

            Gear^.dY.isNegative:= not Gear^.dY.isNegative;

            CheckCollision(Gear);

            Gear^.dX.isNegative:= not Gear^.dX.isNegative;

            Gear^.dY.isNegative:= not Gear^.dY.isNegative;

            end;

        haveCollision:= (Gear^.State and gstCollision) <> 0;

        // restore gear location

        Gear^.X:= tx;

        Gear^.Y:= ty;

        end;

    // if the attack key is pressed, lose rope contact as well

    if (Gear^.Message and gmAttack) <> 0 then

        haveCollision:= false;

    if not haveCollision then

        begin

        if (Gear^.State and gsttmpFlag) <> 0 then

            begin

            if Gear^.Hedgehog^.CurAmmoType <> amParachute then

                RopeWaitCollision(Gear, HHGear)

            else

                RopeDeleteMe(Gear, HHGear)

            end

        end

    else

        if (Gear^.State and gsttmpFlag) = 0 then

            Gear^.State := Gear^.State or gsttmpFlag;

end;

procedure RopeRemoveFromAmmo(Gear, HHGear: PGear);

begin

    if (Gear^.State and gstAttacked) = 0 then

        begin

        OnUsedAmmo(HHGear^.Hedgehog^);

        Gear^.State := Gear^.State or gstAttacked

        end;

    ApplyAmmoChanges(HHGear^.Hedgehog^)

end;

procedure doStepRopeAttach(Gear: PGear);

var 

    HHGear: PGear;

    tx, ty, tt: hwFloat;

begin

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

    Gear^.Y := Gear^.Y - Gear^.dY;

    Gear^.Elasticity := Gear^.Elasticity + _1;

    HHGear := Gear^.Hedgehog^.Gear;

    DeleteCI(HHGear);

    if (HHGear^.State and gstMoving) <> 0 then

        begin

        if TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) then

            SetLittle(HHGear^.dX);

        if HHGear^.dY.isNegative and (TestCollisionYwithGear(HHGear, -1) <> 0) then

            HHGear^.dY := _0;

        HHGear^.X := HHGear^.X + HHGear^.dX;

        Gear^.X := Gear^.X + HHGear^.dX;

        if TestCollisionYwithGear(HHGear, 1) <> 0 then

            begin

            CheckHHDamage(HHGear);

            HHGear^.dY := _0

            //HHGear^.State:= HHGear^.State and (not (gstHHJumping or gstHHHJump));

            end

        else

            begin

            HHGear^.Y := HHGear^.Y + HHGear^.dY;

            Gear^.Y := Gear^.Y + HHGear^.dY;

            HHGear^.dY := HHGear^.dY + cGravity;

            if (GameFlags and gfMoreWind) <> 0 then

                HHGear^.dX := HHGear^.dX + cWindSpeed / HHGear^.Density

            end;

        tt := Gear^.Elasticity;

        tx := _0;

        ty := _0;

        while tt > _20 do

            begin

            if ((hwRound(Gear^.Y+ty) and LAND_HEIGHT_MASK) = 0) and ((hwRound(Gear^.X+tx) and LAND_WIDTH_MASK) = 0) and ((Land[hwRound(Gear^.Y+ty), hwRound(Gear^.X+tx)] and $FF00) <> 0) then

                begin

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

                Gear^.Y := Gear^.Y + ty;

                Gear^.Elasticity := tt;

                Gear^.doStep := @doStepRopeWork;

                Gear^.stepFreq:= 8;

                PlaySound(sndRopeAttach);

                with HHGear^ do

                    begin

                    dX.QWordValue:= dX.QWordValue shl 3;

                    dY.QWordValue:= dY.QWordValue shl 3;

                    State := State and (not (gstAttacking or gstHHJumping or gstHHHJump));

                    Message := Message and (not gmAttack)

                    end;

                RopeRemoveFromAmmo(Gear, HHGear);

                tt := _0;

                exit

                end;

            tx := tx + Gear^.dX + Gear^.dX;