Pacman

program Pacman;

uses Types, QuickDraw, Events, MiscTool;

var

i, j: Integer;

tick: LongInt;

r: Rect;

begin

graphics(320);

clearScreen(black);

hideCursor;

setSolidBackPat(black);

setSolidPenPat(9);

tick := getTick;

{ Draw dots }

for i := 1 to 15 do begin

setRect(r, i * 20, 96, i * 20 + 8, 104);

paintOval(r);

end;

{ Draw Pacman }

setRect(r, 0, 80, 40, 120);

paintArc(r, 120, 300);

for i := 1 to 80 do begin

{ Erase Pacman }

setRect(r, i * 4 - 4, 80, i * 4 + 36, 120);

eraseOval(r);

{ Move Pacman }

setRect(r, i * 4, 80, i * 4 + 40, 120);

if odd(i) then paintArc(r, 100, 340)

else paintArc(r, 120, 300);

{ Digest food }

repeat until getTick - tick > 3;

tick := getTick;

if button(0) then exit;

end;

end.

Pacman munching!

This program teaches simple animation technique, including using system tick to maintain animation speed and reduce flickering.

GSoft BASIC comparison:

DIM R AS RECT

HGR

HCOLOR= 9

SETSOLIDBACKPAT (0)

TICK = GETTICK

! Draw dots

FOR I = 1 TO 15

SETRECT (R, I * 20, 96, I * 20 + 8, 104)

PAINTOVAL (R)

! Draw Pacman

SETRECT (R, 0, 80, 40, 120)

PAINTARC (R, 120, 300)

FOR I = 1 TO 80

! Erase Pacman

SETRECT (R, I * 4 - 4, 80, I * 4 + 36, 120)

ERASERECT (R)

! Move Pacman

SETRECT (R, I * 4, 80, I * 4 + 40, 120)

IF I - INT (I / 2) * 2 > 0 THEN

PAINTARC (R, 100, 340)

ELSE

PAINTARC (R, 120, 300)

END IF

DO UNTIL GETTICK - TICK > 3

LOOP

TICK = GETTICK