// $Id: starparticlesystem.h,v 1.4 2006/08/05 09:08:59 matthew Exp $

//  Fish Supper
//  Copyright (C) 2006 Matthew Clarke <matthew_larcke@lycos.co.uk>
//
//  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.




#ifndef _STAR_PARTICLE_SYSTEM_H_
#define _STAR_PARTICLE_SYSTEM_H_




#include <iostream>
#include "SDL.h"
#include "constants.h"
#include "playdisplay.h"
#include "enums.h"




namespace FS
{
    
// FIXME: This class should be made more general so
// that different types of particle system can be sub-classed
// from it.
class StarParticleSystem
{
    private:
            
        static const int MAX_STARS = 20;
        // launch a new star every n ms:
        static const int LAUNCH_INTERVAL = 30; 
        static const int NUM_FRAMES = 11;
        static const int DURATION = 80; 
        static const int STAR_WIDTH = 30;
        static const int STAR_HEIGHT = 30;
    
        // A particle is basically a lightweight sprite.
        // Unlike a usual sprite, we don't need to worry about
        // collisions. In the case of 'star' particles, no need
        // to track movement either.
        struct StarParticle
        {
            int x;
            int y;
            int start_time;
            int current_frame;
            bool active;
            SDL_Rect isr;   // i.e. image section rect!
        }; // struct StarParticle
        
        bool active;
        bool stopped;
        int start_time;
        int num_stars;
        
        SDL_Rect dest_rect;
        SDL_Rect erase_rect;
        SDL_Rect update_rect;
        int min_x, max_x, min_y, max_y;
        
        StarParticle my_stars[MAX_STARS];
        
        void launch_new_star(int t, SDL_Rect box);
        void draw_stars(PlayDisplay * pd);
        
        // Helper functions
        // FIXME: Put these somewhere all classes can use them
        int min(int a, int b) const { return ((a < b) ? a : b); }
        int max(int a, int b) const { return ((a > b) ? a : b); }
                            
    public:
            
        StarParticleSystem();
        ~StarParticleSystem();
        
        void activate(int t, SDL_Rect box);
        
        // Calling stop() means the system won't launch any new
        // particles but it will continue to update existing ones
        // until they've all died out.
        void stop(int t);
        
        // Is this system in use and therefore in need of updates?
        bool is_active() const { return active; }
        
        bool is_stopped() const { return stopped; }
        
        void update(int time_passed, SDL_Rect box, PlayDisplay * pd);
        
}; // class StarParticleSystem

} // namespace FS    




#endif