/* Photon Model                     */
/* Compile with g++ phot.cpp -l SDL */
#include <stdlib.h>
#include <SDL/SDL.h>
#include <stdio.h>
#include <math.h>
#include "veblib.h"
#include <time.h>
int main(int argc, char *argv[])
{
    char c;
    int waiting = 40;
    int dummy, half = 1;
    int x = 400, y = 300, zp, upd = 0, updc = 1;
    int ox = x, oy = y, amp = 55, blank;
    int xi = 2, yi = 2, oxi = xi, oyi = yi;
    float conv, z = 0, zi = .1, ozi = zi;
    if((SDL_Init(SDL_INIT_VIDEO|SDL_INIT_AUDIO)==-1)) { 
        printf("Could not initialize SDL: %s.\n", SDL_GetError());
        exit(-1);
    }
    conv = amp * .12;
    blank = (int) conv;
    SDL_WM_SetCaption("Photon Schematic", "photon.bmp");
    SDL_WM_SetIcon(SDL_LoadBMP("photon.bmp"), NULL);
    dummy = init_screen();
    ColorFill(color);
    SDL_UpdateRect(screen, 0, 0, 800, 600);
    while(waiting){
       x += xi;
       if(x > 799 || x < 1){
          xi *= -1;
       }
       y += yi;
       if(y > 599 || y < 1){
          yi *= -1;
       }
       z += zi;
       if(z > 1.5 || z < .1){
          zi *= -1;
          if( z < .1){
             if(half == 0){
                half = 1;
                upd ++;
                if(upd > updc){
                   SDL_UpdateRect(screen, 0, 0, 800, 600);
                   upd = 0;
                   SDL_Delay(updc);
                }
                x = ox + oxi;
                xi = oxi;
                zi = ozi;
                yi = oyi;
                if(x > 799 || x < 1){
                   oxi *= -1;
                   xi = oxi;
                }
                y = oy + oyi;
                if(y > 599 || y < 1){
                   oyi *= -1;
                   yi = oyi;
                }
                z = 0;
                ox = x;
                oy = y;
             }
             else{
             half = 0;
             }
          }
       }
       conv = sin(z) * amp;
       zp = (int) conv;
       photon(x, y, zp + blank, 2);
       photon(x, y, zp, half);
       //SDL_UpdateRect(screen, 0, 0, 800, 600);
       
       c = keystroke();
       
       if(c == 'q') break;
       switch(c){
         case 'd':
           SDL_Delay(5000);
           break;
         case 'a':
           blank ++;
           break;
         case 'b':
           if(blank + zp > 0) blank --;
           break;
         case 'c':
           amp ++;
           break;
         case 'e':
           amp --;
           break;
         case 'x':
           xi++;
           oxi = xi;
           ColorFill(color);
           break;
         case 'y':
           yi++;
           oyi = yi;
           ColorFill(color);
           break;
       }

    }
    SDL_Quit();
    exit(0);   
}