(*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2004-2015 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  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;

const

    IsNilHHFatal = false;

procedure doStepRopeAfterAttack(Gear: PGear);

var

    HHGear: PGear;

    tX:     hwFloat;

begin

    HHGear := Gear^.Hedgehog^.Gear;

    if HHGear = nil then

        begin

        OutError('ERROR: doStepRopeAfterAttack called while HHGear = nil', IsNilHHFatal);

        DeleteGear(Gear);

        exit()

        end

    else if not CurrentTeam^.ExtDriven and (FollowGear <> nil) then FollowGear := HHGear;

    tX:= HHGear^.X;

    if WorldWrap(HHGear) and (WorldEdge = weWrap) and

       ((TestCollisionXwithGear(HHGear, 1) <> 0) or (TestCollisionXwithGear(HHGear, -1) <> 0))  then

        begin

        HHGear^.X:= tX;

        HHGear^.dX.isNegative:= hwRound(tX) > leftX + HHGear^.Radius * 2

        end;

    if (HHGear^.Hedgehog^.CurAmmoType = amParachute) and (HHGear^.dY > _0_39) then

        begin

        DeleteGear(Gear);

        ApplyAmmoChanges(HHGear^.Hedgehog^);

        HHGear^.Message:= HHGear^.Message or gmLJump;

        exit

        end;

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

    or (CheckGearDrowning(HHGear))

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

        begin

        DeleteGear(Gear);

        if (TestCollisionYwithGear(HHGear, 1) <> 0) and (GetAmmoEntry(HHGear^.Hedgehog^, amRope)^.Count >= 1) and ((Ammoz[HHGear^.Hedgehog^.CurAmmoType].Ammo.Propz and ammoprop_AltUse) <> 0) and (HHGear^.Hedgehog^.MultiShootAttacks = 0) then

            HHGear^.Hedgehog^.CurAmmoType:= amRope;

        isCursorVisible := false;

        ApplyAmmoChanges(HHGear^.Hedgehog^);

        exit

        end;

    HedgehogChAngle(HHGear);

    if TestCollisionXwithGear(HHGear, hwSign(HHGear^.dX)) <> 0 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

    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

    with HHGear^ do

        begin

        Message := Message and (not gmAttack);

        State := State or gstMoving;

        end;

    RopePoints.Count := 0;

    Gear^.Elasticity := _0;

    Gear^.doStep := @doStepRopeAfterAttack

end;

procedure doStepRopeWork(Gear: PGear);

var

    HHGear: PGear;

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

    lx, ly, cd: LongInt;

    haveCollision,

    haveDivided: boolean;

    wrongSide: boolean;

begin

    HHGear := Gear^.Hedgehog^.Gear;

    if HHGear = nil then

        begin

        OutError('ERROR: doStepRopeWork called while HHGear = nil', IsNilHHFatal);

        DeleteGear(Gear);

        exit()

        end

    else if not CurrentTeam^.ExtDriven and (FollowGear <> nil) then FollowGear := HHGear;

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

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

        begin

        PlaySound(sndRopeRelease);

        RopeDeleteMe(Gear, HHGear);

        exit

        end;

    if GameTicks mod 4 <> 0 then exit;

    tX:= HHGear^.X;

    if WorldWrap(HHGear) and (WorldEdge = weWrap) and

       ((TestCollisionXwithGear(HHGear, 1) <> 0) or (TestCollisionXwithGear(HHGear, -1) <> 0))  then

        begin

        PlaySound(sndRopeRelease);

        RopeDeleteMe(Gear, HHGear);

        HHGear^.X:= tX;

        HHGear^.dX.isNegative:= hwRound(tX) > leftX + HHGear^.Radius * 2;

        exit

        end;

    tX:= HHGear^.X;

    HHGear^.dX.QWordValue:= HHGear^.dX.QWordValue shl 2;

    HHGear^.dY.QWordValue:= HHGear^.dY.QWordValue shl 2;

    if (Gear^.Message and gmLeft  <> 0) and (TestCollisionXwithGear(HHGear, -1) = 0) then

        HHGear^.dX := HHGear^.dX - _0_0032;

    if (Gear^.Message and gmRight <> 0) and (TestCollisionXwithGear(HHGear,  1) = 0) then

        HHGear^.dX := HHGear^.dX + _0_0032;

    // vector between hedgehog and rope attaching point

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

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

    if TestCollisionYwithXYShift(HHGear, 0, 1, 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 TestCollisionXwithXYShift(HHGear, _2*cd, 0, cd, true) = 0 then

            HHGear^.dY := HHGear^.dY + cGravity * 16;

        if (GameFlags and gfMoreWind) <> 0 then

            // apply wind if there's no obstacle

            if TestCollisionXwithGear(HHGear, hwSign(cWindSpeed)) = 0 then

                HHGear^.dX := HHGear^.dX + cWindSpeed * 16 / HHGear^.Density;

        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;

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

        if not ((TestCollisionXwithXYShift(HHGear, _2*hwSign(ropeDx), 0, hwSign(ropeDx), true) <> 0)

        or ((ropeDy.QWordValue <> 0) and (TestCollisionYwithXYShift(HHGear, 0, hwSign(ropeDy), hwSign(ropeDy)) <> 0))) then

            Gear^.Elasticity := Gear^.Elasticity + _1_2;

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

        if not ((TestCollisionXwithXYShift(HHGear, -_2*hwSign(ropeDx), 0, -hwSign(ropeDx), true) <> 0)

        or ((ropeDy.QWordValue <> 0) and (TestCollisionYwithXYShift(HHGear, 0, -hwSign(ropeDy), -hwSign(ropeDy)) <> 0))) then

            Gear^.Elasticity := Gear^.Elasticity - _1_2;

    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 * _1_2; // should be the same as increase step

    ty := mdY * _1_2;

    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] > lfAllObjMask) then

            begin

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

            // old rope pos

            nx := ropeDx * tx;

            ny := ropeDy * tx;

            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);

                sx:= Gear^.dX.isNegative;

                sy:= Gear^.dY.isNegative;

                sb:= Gear^.dX.QWordValue < Gear^.dY.QWordValue;

                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);

            if checkFails(RopePoints.Count <= MAXROPEPOINTS, 'Rope points overflow', true) then exit;

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

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

            haveDivided := true;

            break

            end;

        nx := nx - tx;

        ny := ny - ty;

        // len := len - _1_2 // should be the same as increase step

        len.QWordValue := len.QWordValue - _1_2.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;

            ropeDx:= tx - HHGear^.X;

            ropeDy:= ty - HHGear^.Y;

            if RopePoints.ar[Pred(RopePoints.Count)].b xor (mdX * ropeDy > ropeDx * mdY) then

                begin

                dec(RopePoints.Count);

                Gear^.X := tx;

                Gear^.Y := ty;

                // oops, opposite quadrant, don't restore hog position in such case, just remove the point

                wrongSide:= (ropeDx.isNegative = RopePoints.ar[RopePoints.Count].sx)

                    and (ropeDy.isNegative = RopePoints.ar[RopePoints.Count].sy);

                // previous check could be inaccurate in vertical/horizontal rope positions,

                // so perform this check also, even though odds are 1 to 415927 to hit this

                if (not wrongSide)

                    and ((ropeDx.isNegative = RopePoints.ar[RopePoints.Count].sx)

                      <> (ropeDy.isNegative = RopePoints.ar[RopePoints.Count].sy)) then

                    if RopePoints.ar[RopePoints.Count].sb then

                        wrongSide:= ropeDy.isNegative = RopePoints.ar[RopePoints.Count].sy

                        else

                        wrongSide:= ropeDx.isNegative = RopePoints.ar[RopePoints.Count].sx;

                if wrongSide then

                    begin

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

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

                    end else

                    begin

                    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

            end;

    haveCollision := false;

    if TestCollisionXwithXYShift(HHGear, _2*hwSign(HHGear^.dX), 0, hwSign(HHGear^.dX), true) <> 0 then

        begin

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

        haveCollision := true

        end;

    if TestCollisionYwithXYShift(HHGear, 0, 1*hwSign(HHGear^.dY), 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) + _0_8, HHGear^.dX);

        HHGear^.dY := SignAs(hwAbs(HHGear^.dY) + _0_8, HHGear^.dY)

        end;

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

    if len > _10 then

        begin

        len := _3_2 / 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;

    HHGear^.dX.QWordValue:= HHGear^.dX.QWordValue shr 2;

    HHGear^.dY.QWordValue:= HHGear^.dY.QWordValue shr 2;

    if (not haveCollision) and ((Gear^.State and gsttmpFlag) <> 0) then

        begin

            begin

            PlaySound(sndRopeRelease);

            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;

    if HHGear = nil then

        begin

        OutError('ERROR: doStepRopeAttach called while HHGear = nil', IsNilHHFatal);

        DeleteGear(Gear);

        exit()

        end

    else if not CurrentTeam^.ExtDriven and (FollowGear <> nil) then FollowGear := HHGear;

    // Destroy rope if it touched bouncy or world wrap world edge.

    // TODO: Allow to shoot rope through the world wrap edge and rope normally.

    if (WorldWrap(Gear) and (WorldEdge = weWrap)) or

       ((WorldEdge = weBounce) and ((hwRound(Gear^.X) <= LeftX) or (hwRound(Gear^.X) >= RightX))) then

        begin

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

        HHGear^.Message := HHGear^.Message and (not gmAttack);

        DeleteGear(Gear);

        if (GetAmmoEntry(HHGear^.Hedgehog^, amRope)^.Count >= 1) and ((Ammoz[HHGear^.Hedgehog^.CurAmmoType].Ammo.Propz and ammoprop_AltUse) <> 0) and (HHGear^.Hedgehog^.MultiShootAttacks = 0) then

            HHGear^.Hedgehog^.CurAmmoType:= amRope;

        isCursorVisible := false;

        ApplyAmmoChanges(HHGear^.Hedgehog^);

        exit()

        end;

    DeleteCI(HHGear);

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

        begin

        doStepHedgehogMoving(HHGear);

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

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

        // hedgehog can teleport up to 5 pixels upwards when sliding,

        // so we have to give up the maintained rope length

        // after doStepHedgehogMoving() call and recalculate

        // it based on the gear and current hedgehog positions

        Gear^.Elasticity:= int2hwFloat(hwRound(Distance(Gear^.X - HHGear^.X, Gear^.Y - HHGear^.Y) + _0_001));

        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)] > lfAllObjMask) then

                begin

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

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

                Gear^.Elasticity := tt;

                Gear^.doStep := @doStepRopeWork;

                PlaySound(sndRopeAttach);

                with HHGear^ do

                    begin

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

                    Message := Message and (not gmAttack)