/*********************************************************************
*  snake.bz: is a script made only for fun. It will make a 'snake'   *
*  which will roam around your screen and eat all it can find.       *
*                                                                    *
*  Can be implemented as a screen saver. I'll probably use it as one *
*                                                                    *
*  This file uses a file called random.bz which is crucial. Get it   *
*  before trying to compile this script!!                            *
*                                                                    *
*  snake.bz is set up to use (my)menus/bull0.gr for background       *
*                                                                    *
*  This source file is hereby released to the Public Domain by the   *
*  author: Stig Johansen.                                            *
*  I can be reached at these addresses:                              *
*   BBBSnet:    Stig Johansen@47:1000/101                            *
*   FidoNet:    Stig Johansen@2:210/20                               *
*   SigNet:     Stig Johansen@27:1347/106                            *
*   SkyNet:     Stig Johansen@47:300:110                             *
*                                                                    *
*  Have fun... and: release all of your source codes!!!              *
**********************************************************************/

#include random.bz

var $s_Xarr, $s_Yarr;       // Snake-positions
var $s_arrpos;              // Where we are in the array.
var $s_arrlen;              // How many positions are used.
var $s_color;               // Snake color
var $s_win;                 // Snake window
var $s_steps;               // Steps to go one way (temp.)
var $s_olddir;              // Last direction

function a_clrscr() {
    printf("\e[1;1H\e[2J");
}

function a_gotoxy($x,$y) {
    printf("\e[%u;%uH",$y,$x);
}


/*
   snake_putxy( X coordinate,
                Y coordinate,
                Character);
*/
function snake_putxy($x,$y,$ch) {
    printf("\e[%u;%uH\e[%sm%s",$y,$x,$s_color,$ch);
}


/*
   initsnake( Upper left corner X,
              Upper left corner Y,
              Lower right corner X,
              Lower right corner Y,
              Snake-color (string),
              Snake length);

   Should be called before updatesnake()
*/
function initsnake($x1,$y1,$x2,$y2,$color,$length) {
    var $i;

    $s_win[0] = $x1;
    $s_win[1] = $y1;
    $s_win[2] = $x2;
    $s_win[3] = $y2;

    $s_color = $color;

    $s_arrlen = $length;
    $s_arrpos = 0;

    for ($i=0;$i<($length+1);$i=$i+1) {
        $s_Xarr[$i] = 0;
        $s_Yarr[$i] = 0;
    }

    slongrand((($bv_unum+1)*($bf_sec+1)%($bf_sec+3))%($bf_timleft+3));

    $i = longrand()%($x2-$x1); if ($i<0) $i = $i * -1;
    $s_Xarr[0] = ($i+$x1);
    $i = longrand()%($y2-$y1); if ($i<0) $i = $i * -1;
    $s_Yarr[0] = ($i+$y1);

    $s_steps = 0;
    $s_olddir = -1;

}


/*
   movesnake( Direction of movement );

        1 = Down, left
        2 = Down
        3 = Down, right
        4 = Left
        6 = Right
        7 = Up, left
        8 = Up
        9 = Up, right

   MUST be called after initsnake(), uses a lot of internal variables
*/
function movesnake($direction) {
    var $old_x,$old_y;
    var $char;


    $old_x = $s_Xarr[$s_arrpos];
    $old_y = $s_Yarr[$s_arrpos];
    if ($s_arrpos < $s_arrlen) $s_arrpos = $s_arrpos + 1;
    else $s_arrpos = 0;
    if ($s_Xarr[$s_arrpos]!=0)      /* remove tail */
        snake_putxy($s_Xarr[$s_arrpos],$s_Yarr[$s_arrpos]," ");

    switch ($direction) {
        case 7: {               /* Up, left corner */
            if ($old_x<=$s_win[0]) $s_Xarr[$s_arrpos] = $s_win[2];
            else $s_Xarr[$s_arrpos] = $old_x - 1;
            if ($old_y<=$s_win[1]) $s_Yarr[$s_arrpos] = $s_win[3];
            else $s_Yarr[$s_arrpos] = $old_y - 1;
            $char = "\\";
            break;
        }
        case 8: {               /* Up */
            $s_Xarr[$s_arrpos] = $old_x;
            if ($old_y<=$s_win[1]) $s_Yarr[$s_arrpos] = $s_win[3];
            else $s_Yarr[$s_arrpos] = $old_y - 1;
            $char = "|";
            break;
        }
        case 9: {               /* Up, right corner */
            if ($old_x>=$s_win[2]) $s_Xarr[$s_arrpos] = $s_win[0];
            else $s_Xarr[$s_arrpos] = $old_x + 1;
            if ($old_y<=$s_win[1]) $s_Yarr[$s_arrpos] = $s_win[3];
            else $s_Yarr[$s_arrpos] = $old_y - 1;
            $char = "/";
            break;
        }
        case 4: {               /* Left */
            if ($old_x<=$s_win[0]) $s_Xarr[$s_arrpos] = $s_win[2];
            else $s_Xarr[$s_arrpos] = $old_x - 1;
            $s_Yarr[$s_arrpos] = $old_y;
            $char = "-";
            break;
        }
        case 6: {               /* Right */
            if ($old_x>=$s_win[2]) $s_Xarr[$s_arrpos] = $s_win[0];
            else $s_Xarr[$s_arrpos] = $old_x + 1;
            $s_Yarr[$s_arrpos] = $old_y;
            $char = "-";
            break;
        }
        case 1: {               /* Down, left corner */
            if ($old_x<=$s_win[0]) $s_Xarr[$s_arrpos] = $s_win[2];
            else $s_Xarr[$s_arrpos] = $old_x - 1;
            if ($old_y>=$s_win[3]) $s_Yarr[$s_arrpos] = $s_win[1];
            else $s_Yarr[$s_arrpos] = $old_y + 1;
            $char = "/";
            break;
        }
        case 2: {               /* Down */
            $s_Xarr[$s_arrpos] = $old_x;
            if ($old_y>=$s_win[3]) $s_Yarr[$s_arrpos] = $s_win[1];
            else $s_Yarr[$s_arrpos] = $old_y + 1;
            $char = "|";
            break;
        }
        case 3: {               /* Down, right corner */
            if ($old_x>=$s_win[2]) $s_Xarr[$s_arrpos] = $s_win[0];
            else $s_Xarr[$s_arrpos] = $old_x + 1;
            if ($old_y>=$s_win[3]) $s_Yarr[$s_arrpos] = $s_win[1];
            else $s_Yarr[$s_arrpos] = $old_y + 1;
            $char = "\\";
            break;
        }
    }
 /*
    a_gotoxy(60,22);
    printf("\e[KDirection: %i\n",$direction);
    a_gotoxy(60,23);
    printf("\e[KOld XY: (%i,%i)\n",$old_x,$old_y);
    a_gotoxy(60,24);
    printf("\e[KNew XY: (%i,%i)\n",$s_Xarr[$s_arrpos],$s_Yarr[$s_arrpos]);
 */
    snake_putxy($s_Xarr[$s_arrpos],$s_Yarr[$s_arrpos],$char);

}


/*
   updatesnake( );
   Should ONLY be called after a initsnake() call.
*/
function updatesnake() {
    var $i, $notok;

    if ($s_steps==0) {
        $i = longrand()%20;
        if ($i<0) $i = $i * -1;

        $s_steps = $i + 1;

        $notok = 1;
        while ($notok) {
            $i = longrand()%8;
            if ($i<0) $i = $i * -1;
            switch ($i) {
                case 0: { if ($s_olddir!=8) $notok = 0; break; }
                case 1: { if ($s_olddir!=7) $notok = 0; break; }
                case 2: { if ($s_olddir!=6) $notok = 0; break; }
                case 3: { if ($s_olddir!=5) $notok = 0; break; }
                case 5: { if ($s_olddir!=3) $notok = 0; break; }
                case 6: { if ($s_olddir!=2) $notok = 0; break; }
                case 7: { if ($s_olddir!=1) $notok = 0; break; }
                case 8: { if ($s_olddir) $notok = 0; break; }
            }
        }
        $s_olddir = $i;
    } else $s_steps = $s_steps - 1;

    movesnake($s_olddir+1);
    delay(1);
}


/*
   :) (optional) (really a test-screen)
*/
function skryteskjerm() {
    var $i;

    initsnake(1,1,80,24,"36",50);               // S
    $s_Xarr[0] = 11; $s_Yarr[0] = 4;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"-");
    for ($i=0;$i<10;$i=$i+1) movesnake(4);
    for ($i=0;$i<5;$i=$i+1) movesnake(2);
    for ($i=0;$i<10;$i=$i+1) movesnake(6);
    for ($i=0;$i<5;$i=$i+1) movesnake(2);
    for ($i=0;$i<10;$i=$i+1) movesnake(4);

    initsnake(1,1,80,24,"36",40);               // N
    $s_Xarr[0] = 15; $s_Yarr[0] = 14;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"|");
    for ($i=0;$i<10;$i=$i+1) movesnake(8);
    for ($i=0;$i<10;$i=$i+1) movesnake(3);
    for ($i=0;$i<10;$i=$i+1) movesnake(8);

    initsnake(1,1,80,24,"36",40);               // A
    $s_Xarr[0] = 29; $s_Yarr[0] = 14;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"|");
    for ($i=0;$i<10;$i=$i+1) movesnake(8);
    for ($i=0;$i<10;$i=$i+1) movesnake(6);
    for ($i=0;$i<10;$i=$i+1) movesnake(2);

    initsnake(1,1,80,24,"36",20);
    $s_Xarr[0] = 29; $s_Yarr[0] = 9;
    for ($i=0;$i<10;$i=$i+1) movesnake(6);


    initsnake(1,1,80,24,"36",20);               // K
    $s_Xarr[0] = 43; $s_Yarr[0] = 4;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"|");
    for ($i=0;$i<10;$i=$i+1) movesnake(2);

    initsnake(1,1,80,24,"36",20);
    $s_Xarr[0] = 49; $s_Yarr[0] = 4;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"/");
    for ($i=0;$i<5;$i=$i+1) movesnake(1);
    for ($i=0;$i<1;$i=$i+1) movesnake(2);
    for ($i=0;$i<4;$i=$i+1) movesnake(3);

    initsnake(1,1,80,24,"36",50);               // E
    $s_Xarr[0] = 62; $s_Yarr[0] = 4;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"-");
    for ($i=0;$i<10;$i=$i+1) movesnake(4);
    for ($i=0;$i<10;$i=$i+1) movesnake(2);
    for ($i=0;$i<10;$i=$i+1) movesnake(6);

    initsnake(1,1,80,24,"36",10);
    $s_Xarr[0] = 52; $s_Yarr[0] = 9;
    for ($i=0;$i<5;$i=$i+1) movesnake(6);

    initsnake(1,1,80,24,"36",50);               // S
    $s_Xarr[0] = 76; $s_Yarr[0] = 4;
    snake_putxy($s_Xarr[0],$s_Yarr[0],"-");
    for ($i=0;$i<10;$i=$i+1) movesnake(4);
    for ($i=0;$i<5;$i=$i+1) movesnake(2);
    for ($i=0;$i<10;$i=$i+1) movesnake(6);
    for ($i=0;$i<5;$i=$i+1) movesnake(2);
    for ($i=0;$i<10;$i=$i+1) movesnake(4);

    a_gotoxy(18,20);
    printf("\e[1;33mSnakes/$ by Stig Johansen v9514.14");
    a_gotoxy(28,22);
    printf("\e[35mBarCode BBS\e[0m");
}

 
function main() {
    var $old_line;

    $old_line = $bu_pagelength;
    $bu_pagelength = 0;

    a_clrscr();
    skryteskjerm();
    delay(10);
    a_clrscr();
    showfile(strcat($bl_menudir,"bull0.gr"));
    initsnake(1,1,80,24,"1;33",20);
    while ((!kbhit())&&($bv_carrier||($bn_speed==0))) updatesnake();
    $bu_pagelength = $old_line;
    a_clrscr();
}