/*
 *   ttyvaders     Textmode shoot'em up
 *   Copyright (c) 2002 Sam Hocevar <sam@zoy.org>
 *                 All Rights Reserved
 *
 *   $Id: collide.c,v 1.11 2003/01/06 12:22:58 sam Exp $
 *
 *   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stdlib.h>

#include "common.h"

void collide_weapons_tunnel( game *g, weapons *wp, tunnel *t, explosions *ex )
{
    int i, j, x, y;

    for( i = 0; i < WEAPONS; i++ )
    {
        x = wp->x[i] >> 4;
        y = wp->y[i] >> 4;

        switch( wp->type[i] )
        {
        case WEAPON_LIGHTNING:
        case WEAPON_NONE:
            break;
        case WEAPON_SEEKER:
        case WEAPON_BOMB:
        case WEAPON_FRAGBOMB:
            if( y < 0 || y >= g->h )
            {
                break;
            }

            if( x <= t->left[y]
                 || x >= t->right[y] )
            {
                int damage = wp->type[i] == WEAPON_SEEKER ? 1 : 2;

                add_explosion( g, ex, x, y, 0, 1, wp->type[i] == WEAPON_SEEKER ? EXPLOSION_SMALL : EXPLOSION_MEDIUM );

                if( x <= t->left[y] )
                {
                    if( y-2 >= 0 ) t->left[y-2] -= damage - 1;
                    if( y-1 >= 0 ) t->left[y-1] -= damage;
                    t->left[y] -= damage + 1;
                    if( y+1 < g->h ) t->left[y+1] -= damage;
                    if( y+2 < g->h ) t->left[y+2] -= damage - 1;
                }
                else
                {
                    if( y-2 >= 0 ) t->right[y-2] += damage - 1;
                    if( y-1 >= 0 ) t->right[y-1] += damage;
                    t->right[y] += damage + 1;
                    if( y+1 < g->h ) t->right[y+1] += damage;
                    if( y+2 < g->h ) t->right[y+2] += damage - 1;
                }

                if( wp->type[i] == WEAPON_FRAGBOMB )
                {
                    wp->n[i] = -1;
                }
                else
                {
                    wp->type[i] = WEAPON_NONE;
                }
            }
            break;
        case WEAPON_LASER:
            for( j = GET_MIN( 0, wp->vy[i] >> 4 ) ;
                 j < GET_MAX( 0, wp->vy[i] >> 4 ) ;
                 j++ )
            {
                if( y+j >= g->h || y+j < 0 )
                {
                    continue;
                }

                if( x <= t->left[y+j] || x >= t->right[y+j] )
                {
                    add_explosion( g, ex, x, y+j, 0, 1, EXPLOSION_SMALL );
                    wp->type[i] = WEAPON_NONE;

                    if( x <= t->left[y+j] )
                    {
                        if( y+j-1 >= 0 ) t->left[y+j-1]--;
                        t->left[y+j] -= 2;
                        if( y+j+1 < g->h ) t->left[y+j+1]--;
                    }
                    else
                    {
                        if( y+j-1 >= 0 ) t->right[y+j-1]++;
                        t->right[y+j] += 2;
                        if( y+j+1 < g->h ) t->right[y+j+1]++;
                    }
                    break;
                }
            }
            break;
        case WEAPON_BEAM:
            if( wp->n[i] > 19 )
            {
                break;
            }

            j = (29 - wp->n[i]) * (29 - wp->n[i]) / 8;
            j = GET_MIN( y, j );

            for( ; j > 0 ; j-- )
            {
                if( x - 2 <= t->left[y-j] )
                {
                    add_explosion( g, ex, GET_MIN(t->left[y-j], x+3), y-j, 0, 1, EXPLOSION_SMALL );
                    t->left[y-j] -= GET_RAND(0,3);
                }
                else if( x + 3 >= t->right[y-j] )
                {
                    add_explosion( g, ex, GET_MAX(t->right[y-j], x-2), y-j, 0, 1, EXPLOSION_SMALL );
                    t->right[y-j] += GET_RAND(0,3);
                }
            }
            break;

        case WEAPON_NUKE:
            /* The nuke does not break the tunnel */
            break;
        }
    }
}

void collide_weapons_aliens( game *g, weapons *wp, aliens *al, explosions *ex )
{
    int i, j, k, x, y;

    for( i = 0; i < WEAPONS; i++ )
    {
        int ok = 0;
        int r;

        x = wp->x[i] >> 4;
        y = wp->y[i] >> 4;

        switch( wp->type[i] )
        {
        case WEAPON_LIGHTNING:
        case WEAPON_NONE:
            break;
        case WEAPON_NUKE:
            /* Big nuke */
            r = (29 - wp->n[i]) * (29 - wp->n[i]) / 8;

            for( j = 0; j < ALIENS; j++ )
            {
                if( al->type[j] == ALIEN_NONE || al->life[j] < 0 )
                {
                    continue;
                }

                if( wp->n[i] == 0 /* Nuke destroys _everything_ */ ||
                    (al->x[j] - x) * (al->x[j] - x)
                      + 4 * (al->y[j] - y) * (al->y[j] - y)
                    <= r * r )
                {
                    /* Kill alien, not nuke */
                    al->life[j] -= 10;
                }
            }
            break;

        case WEAPON_BEAM:
            if( wp->n[i] > 19 )
            {
                break;
            }

            r = (29 - wp->n[i]) * (29 - wp->n[i]) / 8;

            for( j = 0; j < ALIENS; j++ )
            {
                if( al->type[j] == ALIEN_NONE || al->life[j] < 0 )
                {
                    continue;
                }

                if( x >= al->x[j] && x <= al->x[j] + 4
                     && y >= al->y[j] + 2 && y-5-r <= al->y[j] )
                {
                    al->life[j] -= 4;
                }
            }
            break;

        case WEAPON_LASER:
            for( j = 0; j < ALIENS; j++ )
            {
                if( al->type[j] == ALIEN_NONE || al->life[j] < 0 )
                {
                    continue;
                }

                for( k = GET_MIN( 0, wp->vy[i] >> 4 ) ;
                     k < GET_MAX( 0, wp->vy[i] >> 4 ) ;
                     k++ )
                {
                    if( x >= al->x[j] && x <= al->x[j] + 4
                         && y+k >= al->y[j] && y+k <= al->y[j] + 2 )
                    {
                        al->life[j]--;
                        ok = 1;
                        break;
                    }
                }
            }

            if( ok )
            {
                add_explosion( g, ex, x, y+1, 0, 0, EXPLOSION_SMALL );
                wp->type[i] = WEAPON_NONE;
            }
            break;

        case WEAPON_SEEKER:
        case WEAPON_BOMB:
        case WEAPON_FRAGBOMB:
            for( j = 0; j < ALIENS; j++ )
            {
                if( al->type[j] == ALIEN_NONE || al->life[j] < 0 )
                {
                    continue;
                }

                if( x >= al->x[j] && x <= al->x[j] + 4
                     && y >= al->y[j] && y <= al->y[j] + 2 )
                {
                    al->life[j] -= wp->type[i] == WEAPON_SEEKER ? 1 : 5;
                    ok = 1;
                }
            }

            if( ok )
            {
                add_explosion( g, ex, x, y+1, 0, 0, wp->type[i] == WEAPON_SEEKER ? EXPLOSION_SMALL : EXPLOSION_MEDIUM );

                if( wp->type[i] == WEAPON_FRAGBOMB )
                {
                    wp->n[i] = -1;
                }
                else
                {
                    wp->type[i] = WEAPON_NONE;
                }
            }
            break;
        }
    }
}

void collide_player_tunnel( game *g, player *p, tunnel *t, explosions *ex )
{
    if( p->dead )
    {
        return;
    }

    if( p->x <= t->left[p->y] )
    {
        p->x += 3;
        p->vx = 2;
        add_explosion( g, ex, p->x+1, p->y-1, 0, 0, EXPLOSION_SMALL );
        p->life -= 180;
    }
    else if( p->x + 5 >= t->right[p->y] )
    {
        p->x -= 3;
        p->vx = -2;
        add_explosion( g, ex, p->x+4, p->y-1, 0, 0, EXPLOSION_SMALL );
        p->life -= 180;
    }
}