16-bit DOS game. Download binary from https://tomaes.itch.io/ninja-blitz

nnjblitz.pas

{
   Ninja Blitz
   
   A spin on city bomber games
   for 1980s era 16 bit DOS PCs
   
   designed & written by 
   Thomas "tomaes" Gruetzmacher 
   in May 2020

   LICENSE: CC BY-NC 4.0
   https://creativecommons.org/licenses/by-nc/4.0/legalcode
}

{
     2020-05-22: $12.3 audio toggle during attack mode fix
     2020-05-20: $12.2 level highscore, optimized code (-> smaller .exe)
     2020-05-15: $11.2 public release
}

uses crt;

const REV = '$12.3'; { 2020-05-08/09/10 ..15+}

    LASTX = 40; 
    LASTY = 50;

    LASTLV = 9; { final level }

    CHR_BO = '*'; CHR_B2 = #254; {big dot}
    CHR_PL = '='; CHR_B1 = #219; {full char}
    CHR_AT = 'v'; CHR_B3 = '|' ;
    CHR_TR = '.'; CHR_SC = '$' ;
    CHR_TR2= ' ';

    MAP_EMPTY = 0; MAP_CASH = 2;
    MAP_BLOCK = 1; MAP_GOLD = 3;
    MAP_DETON = 4;

    KEY_ENTER = #13; KEY_ESC   = #27;
    KEY_DOWN  = #80; KEY_SPACE = #32;

    PL_LV_COLORS : array[1..10] of byte =
     ( White, LightRed, LightMagenta, LightGray, LightCyan,
       Blue, Red, Magenta, DarkGray+Blink, Black );

var px, py  : byte;    { player pos }
    ay, ar  : byte;    { attack-from y pos, attack range/time }
    hp, ohp : byte;    { attack HP }
    ps, ph  : byte;    { player shots'n'hits }
    cc      : byte;    { base city color }
    lv      : byte;    { level }
    sc, hl  : integer; { score, highest level }
    at      : boolean; { attack mode }
    ch      : char;
    playSfx : boolean;

    f  : array[1..LASTX, 1..LASTY] of 0..4;

(********************************************************)

function rnd(_r: word): word;
begin
  rnd := random(_r);
end;

function onein(_r: word): boolean;
begin
  onein := (rnd(_r) = 0);
end;

procedure gxy(_x, _y: byte);
begin
  gotoxy(_x, _y);
end;

procedure color(_c: byte);
begin
  textcolor(_c);
end;

procedure waitForKey;
var _ch: char;
begin
  _ch := readkey;
end;

procedure stopSfx;
begin
  nosound;
end;

procedure sfx(_f,_d: word);
begin
  if playSfx then sound(_f);
  delay(_d);
  if playSfx then stopSfx;
end;

procedure toggleAudio;
begin
  playSfx := not playSfx;
  if not playSfx then stopSfx;
end;

(********************************************************)

procedure delPlayerYline;
var y: byte;

begin
  for y :=1 to py-1 do begin
    gxy(px, y);
    write(' ');
  end;
end;


procedure eoLevelAnimation;
var x, y: byte;
    i, c: byte;

begin

  for i := ord('9') downto ord(' ') do begin

    case i-ord(' ') of {explosion fade-out}
      0..10: c := Blue;
     11..15: c := DarkGray;
     16..20: c := LightGray;
     21..22: c := Yellow;
         23: c := LightMagenta;
     24..25: c := White;
    end;

    color(c);

    for y := 1 to LASTY do  begin
    for x := 1 to LASTX do  begin
      if (f[x,y] <> 0) then begin
        gxy(x,y);
        case rnd(3) of
         0: write( CHR_B1 );
         1: write( CHR_B2 );
         2: write( CHR_B3 );
        end;
      end;
    end;
    end;

    sfx(1000 - i*10, 20);
  end;

end;


procedure renderScore;
var s: string;
    y: byte;

begin
  str(sc, s);

  { ready to detonate? indicate in score display }
  if sc >= 1000 then begin
    if (sc mod 2 = 0) then insert( CHR_BO, s, 0 )
                      else insert( ' ', s, 0)
  end
  else insert( CHR_SC, s, 0 );

  for y := 1 to length(s) do
  begin
    gxy(1, y); write(s[y]);
  end;

  gxy(1, length(s)+1 );
  write(' ');

  str(lv, s);
  insert('#', s, 0);

  for y := 1 to length(s) do
  begin
    gxy(LASTX, y); write(s[y]);
  end;
end;


procedure renderHowTo;
var txt : string;
    i,c : byte;
    _d  : byte;

begin
  txt := '#'#15'briefing'#4'##';
  txt := txt + 'x hit space to dive down#';
  txt := txt + 'x try to grab ('#14'$'#4') from up high#';
  txt := txt + 'x avoid going through walls#';
  txt := txt + 'x if you have $1000, attack ('#12'*'#4')#';
  txt := txt + '  to detonate everything and#';
  txt := txt + '  move on to the next stage#';
  txt := txt + 'x the game ends when your#';
  txt := txt + '  cash score is gone!##'#6;
  txt := txt + 'good luck!';

  _d := 30;
  gxy(1,13);

  for i := 1 to length(txt) do begin

    if keypressed then begin
      ch := readkey;
      if ch in ['m','M'] then toggleAudio
                         else _d := 0;
    end;

    case txt[i] of
      chr(Black)..
      chr(White) : color( ord(txt[i]) );
             '#' : write( #10#13#10#13'   > ');
              else write( UpCase(txt[i]) );
    end;

    if (txt[i] <> ' ') then
    begin
      if _d > 0 then sfx(200 + i, 1);
      delay(_d);
    end;

  end;

end;


procedure makeLevel;
var x, y, r : byte;
    h       : byte;

begin
  cc := rnd(10) + 1;

  fillChar(f, sizeof(f), 0 );

  for x:= 6 to LASTX - 5 do
  begin
    { height of building }
    h := LASTY - rnd(10+lv div 2) + lv div 2 - 1;

    for y:= LASTY downto h do
    begin
      color(cc + y mod 4);
      f[x, y] := MAP_BLOCK;
      gxy(x,y);
      if (y mod 2 = 0) then
        write(CHR_B1)
      else if not onein(7) then write(CHR_B2)
                           else write(CHR_B3);
    end;

  end;

   r := 0;

   { render prizes (fewer for higher levels) }
   repeat
     inc(r);
     repeat
       x := 6 + rnd(LASTX - 10);
       y := LASTY - rnd(LASTY div 4);
     until f[x, y] = MAP_BLOCK;

     gxy(x, y);
     color(Yellow);
     write(CHR_SC);
     f[x, y] := MAP_CASH;
   until (r > 10-lv); { saved score becomes important in later levels }

  { (sometimes) render a big prize at the bottom}
  if onein(10) then begin
    x := 3 + rnd(LASTX - 4);
    y := LASTY;
    f[x,y] := MAP_GOLD;
  
    gxy(x,y);
    color( LightMagenta );
    write(CHR_SC);
  end;

  {render detonator at the bottom}
  x := 3 + rnd(LASTX - 4);
  y := LASTY;
  f[x,y] := MAP_DETON;

  gxy(x,y);
  color(LightRed);
  write(CHR_BO);

end;


procedure shufflePrizes; { shuffle prizes with adjacent space randomly }
var x,y, rx: word;

begin

  for x := 2 to LASTX-1 do begin

    for y := 1 to LASTY-1 do
      if f[x,y] = MAP_CASH then break;

    if (f[x,y] = MAP_CASH) then begin
      
      repeat
        rx := x + random(3)-1;
      until rx <> x;

      if rx < 1 then rx := 1;
      if rx > LASTX-1 then rx := LASTX-1;

      if (f[rx, y  ] =  MAP_EMPTY) and 
         (f[rx, y+1] <> MAP_EMPTY) then
         begin         
           f[x,  y] := MAP_EMPTY;
           f[rx, y] := MAP_CASH;   
           gxy(x, y); write(' ');
           gxy(rx,y); color(Yellow); write(CHR_SC);
         end;         
         
    end;   
  end;

end;


procedure resetPlayer;
begin
  ps := 0; ph := 0;
  px := 2; py := 1;
  ar := 0; ay := py;

  hp := 5 + rnd(4);
  ohp:= hp;

  at := false;
end;

(********************************************************)

var i: integer;

label re;

begin

  randomize;
  textmode(Font8x8);
  playSfx := true;

  renderHowTo;
  waitForKey;
  hl := 1;

re:

  lv := 1;
  sc := 300;
  clrscr;
  makeLevel;
  resetPlayer;

  gxy(16, LASTY div 2 - 4);
  color(White);
  write('GET READY');
  sfx(1000, 20);
  delay(1000);

  gxy(1, LASTY div 2 - 4); clrEol;

  repeat
    dec(sc);

    color( PL_LV_COLORS[lv] );
    renderScore;

    gxy(px, py);
    if at then begin
      if ar > 0 then write(CHR_AT)
    end
    else write(CHR_PL);

    if not at then sfx( sc*2, 2);

    if at then begin
      if playSfx then sound(80+ar*5);
      delay(10);
    end
    else delay(100);

    if (lv > 2) and not at then shufflePrizes; { lv 3+ prizes can be moving targets }

    if at then inc(ar); { attack range bonus: long shots prefered }

    if at then begin    { render attack trail }
      for i := ay+1 to ay+ar-1 do begin
        gxy(px, i);
        if ((i-ar) mod 30 = 0) then write(CHR_TR2)
                               else write(CHR_TR);
      end;
    end else begin
      gxy(px, py);
      write(' ');
    end;

    case f[px,py] of
       MAP_BLOCK: begin
                    if at then begin       { attack block hit }
                      dec(hp);
                      dec(sc, (10-hp)*10 );
                      sfx(500, 50);
                    end else
                      sc := 0;             { normal block crash: instant death }
                  end;
       MAP_CASH:  begin
                    inc(sc, 300);          { cash hit; possible from side }
                    sfx(200, 50);
                    sfx(400, 50);
                    hp := 0;
                    inc(ph);
                    inc(sc, ar*2)          { range bonus }
                  end;
       MAP_GOLD:  begin
                    inc(sc, 300*2);        { big cash/gold hit }
                    sfx(300, 50);
                    sfx(500, 50);
                    sfx(600, 50);
                    hp := 0;
                    inc(ph);
                    inc(sc, ar*2)          { range bonus }
                  end;
       MAP_DETON: begin                    { end-of-level detonator hit}
                    eoLevelAnimation;
                    dec(sc, 1000);
                    inc(lv);
                    clrscr;
                    for i := 0 to 400 do sfx( rnd(1000), 1 );
                    makeLevel;
                    resetPlayer;
                    if (sc > 0) and (sc < 500) then sc := 500;  { min. score when alive in the next level }
                  end;
    end;

    f[px, py] := MAP_EMPTY;

    if not at then
    begin
      if (px < LASTX - 1) then inc(px) else
      begin
       px := 2;
       inc(py);
      end;
    end else begin
      inc(py);
      if (py > LASTY) and (ohp - hp = 0) then
      begin
        dec(sc, 50);    { blank shot }
        sfx(30, 200);   { silent on windows! }
      end;

      if (py > LASTY) or (hp = 0) then begin
        delPlayerYLine; { continue from attack position }
        py := ay;
        inc(py);        { ...but closer to the bottom   }
        at := false;
        hp := 5 + rnd(4);
        ohp:= hp;
      end;
    end;

    if keypressed then
    begin
      ch := readkey;
      if not at and ((ch = KEY_SPACE) or (ch = KEY_DOWN)) then
      begin
        gxy(px, py); write(' ');
        at := true;
        ay := py;
        ar := 0;
        inc(ps);
      end;
      { pray to the cheat gods }
      if ch = '$' then begin
        i := rnd(1000)-500;
        inc(sc, i);
        sfx(580+i, 200);
      end;
      { skip level cheat }
      if ch = '>' then begin
        inc(lv);
        clrscr;
        makeLevel;
        resetPlayer;
      end;
      { play sounds or not }
      if ch in ['M','m'] then toggleAudio;              
    end;

  { user exit, player crash or level cap }
  until (ch = KEY_ESC) or (sc <= 0) or (lv > LASTLV);
  
  sfx(100, 100);
  gxy(15, LASTY div 2 - 4);

  color(White);
  if (lv > LASTLV) then writeln('.!AMAZiNG!.')
                   else writeln('NiNjA BLiTZ');

  gxy(11, LASTY div 2 - 2);
  color(Red);
  writeln('HITS:', ph, '/', ps,' ON LEVEL:', lv );
  gxy(10, LASTY div 2 + 1);
  color(Red + Blink);
  writeln('<ENTER> TO TRY AGAIN!');

  gxy(14, LASTY div 2 + 5);

  if lv > hl then begin
    hl := lv;
    color(Yellow);
    write(' BEST LEVEL!');
  end else begin
    color(cc);
    write(' max level:', hl, ' ');
  end;

  repeat
    ch := readkey;
  until ch in [KEY_ESC, KEY_ENTER];

  if (ch = KEY_ENTER) then goto re;

  textmode(c80);
  color(White);
  writeln('Written in May 2020 (rev. ', REV,')'#13#10);
  color(cc);
  writeln('> github.com/tomaes');
  writeln('> tomaes.itch.io');

  delay(1000);

end.