// the Snake
// Copyright (c)1996 Fredrik Wangel (WaF)
//

#include <dos.h>
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include "snake.h"

void waitretrace(void);
void waitdisplay(void);
int  keyhit(void);
void flushkbd(void);
void setborderc(byte color);
void show_display(void);
void hide_display(void);
void draw_score(void);
void fade_to_black(byte start, byte stop, byte steps);
void fade_to_color(byte start, byte stop, byte steps);

#define TRUE  '-'/'-'
#define FALSE '-'-'-'

#define KEY_SOUND 'S'
#define KEY_ESC   27

#define KEY_UP    72
#define KEY_DOWN  80
#define KEY_LEFT  75
#define KEY_RIGHT 77

#define SCRSX  80
#define XSIZE  80
#define YSIZE  40
#define BLOCKS 20
#define LX2POS 44
#define LXPOS   1
#define LYPOS  YSIZE + 2
#define GP     ((YSIZE * BLOCKS) / XSIZE)    // Base points

#define ADDSNAKE   15 // random(x) at increase
#define LOOSESNAKE  4 // and decrease respectively
#define BEGINSNAKE  2 // starting length of the snake
#define FROGAMOUNT  5 // number of frogs

#define HI(a) (a & 0xff00) / 0x100
#define LO(a) (a & 0x00ff)
#define FOREVER for(;;)

byte key, firsttime = 1, ljud = 1;
byte grid[XSIZE][YSIZE];
byte frx[FROGAMOUNT], fry[FROGAMOUNT];
int  snx[1500], sny[1500];
int  length, head, tail;
int  grow, decline, frogtime[FROGAMOUNT];
int  millifemtio, tid;
long score;
long bestscore = 0;
int  besttid = 0, bestlength = 0;

const word Clear = 0x2000 + byte(' ');
const word Frog  = 0x2A00 + byte('