/*
 *  Copyright (C) 1999 Peter Amstutz
 *
 *  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; either version 2 of *the
 *  License, or (at your option) any later version.
 *
 *  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 <stdio.h>
#include <math.h>
#include "../ballistics.h"
#include "../terrain.h"
#include "../aiexterns.h"
#include "roller.h"

Shellstat_bal
wepRollerInit(struct Projectilepos_bal *prjpos, void **guide,
	      Shellstat_bal(*initexplosion) (struct Projectilepos_bal *
					     prjpos, void **explosioninfo),
	      void **explosioninfo)
{
    Player_pl *plhit = NULL;
    int ix, iy;

    *guide = NULL;

    if(balCheckTankIntersect(prjpos->x, prjpos->y, &plhit, &ix, &iy))
    {
	prjpos->x = ix;
	prjpos->y = iy;
	aihExplosionHook(prjpos);
	return initexplosion(prjpos, explosioninfo);
    }
    else
    {
	if(terCheckPos(ter_data, prjpos->x + 1, prjpos->y + 1) &&
	   !terCheckPos(ter_data, prjpos->x - 1, prjpos->y + 1))
	{
	    prjpos->vx = -1;
	}
	if(terCheckPos(ter_data, prjpos->x - 1, prjpos->y + 1) &&
	   !terCheckPos(ter_data, prjpos->x + 1, prjpos->y + 1))
	{
	    prjpos->vx = 1;
	}
	prjpos->rox = prjpos->ox = prjpos->x;
	prjpos->roy = prjpos->oy = prjpos->y;
	return FLYING;
    }
}

Shellstat_bal
wepRollerGuidance(void *info, struct Projectilepos_bal * prjpos,
		  Shellstat_bal(*initexplosion) (struct Projectilepos_bal *
						 prjpos,
						 void **explosioninfo),
		  void **explosioninfo)
{
    int i, ix, iy;
    Player_pl *plhit = NULL;

    prjpos->rox = prjpos->ox = prjpos->x;
    prjpos->roy = prjpos->oy = prjpos->y;
    for(i = 0; i < 20; i++)
    {
	if(balCheckTankIntersect(prjpos->x, prjpos->y + 5, &plhit, &ix, &iy))
	{
	    prjpos->x = ix;
	    prjpos->y = iy;
	    aihExplosionHook(prjpos);
	    return initexplosion(prjpos, explosioninfo);
	}
	if(prjpos->x <= 0 || prjpos->x >= ter_sizex)
	{
	    prjpos->x = -1;
	    prjpos->y = -1;
	    return FREEING;
	}
	if(!terCheckPos(ter_data, prjpos->x, prjpos->y - 1) &&
	   prjpos->vy == 0 && prjpos->y > 0)
	{
	    prjpos->y--;
	    continue;
	}
	if(prjpos->vx > 0)
	{
	    if(!terCheckPos(ter_data, prjpos->x + 1, prjpos->y))
	    {
		prjpos->x++;
		prjpos->vy = 0;
		continue;
	    }
	    else
	    {
		if(!terCheckSpan
		   (&ter_data[(int) rint(prjpos->x) + 1], prjpos->y, 2))
		{
		    prjpos->y++;
		    prjpos->vy = 1;
		    continue;
		}
		else
		{
		    aihExplosionHook(prjpos);
		    return initexplosion(prjpos, explosioninfo);
		}
	    }
	}
	else
	{
	    if(!terCheckPos(ter_data, prjpos->x - 1, prjpos->y))
	    {
		prjpos->x--;
		prjpos->vy = 0;
		continue;
	    }
	    else
	    {
		if(!terCheckSpan
		   (&ter_data[(int) rint(prjpos->x) - 1], prjpos->y, 2))
		{
		    prjpos->y++;
		    prjpos->vy = 1;
		    continue;
		}
		else
		{
		    aihExplosionHook(prjpos);
		    return initexplosion(prjpos, explosioninfo);
		}
	    }
	}
    }
    return FLYING;
}

Shellstat_bal
wepRollerExplosionInit(struct Projectilepos_bal * prjpos, void **explosioninfo)
{
    struct Projectilelist_bal *prj;
    Weapon_wep *wp;

    wp = wepLookupWeapon("Roller Ball");
    prj =
	balNewShotXY(prjpos->id, 0, prjpos->x, prjpos->y, prjpos->vx,
		     prjpos->vy, wp);
    prj->stat = INITSHOT(prj);

    return FREEING;
}