Stars
program Stars;
uses Types, QuickDraw, Events, MiscTool;
type
Star = Record
x, y, speed: Integer;
end;
var
i: Integer;
tick: LongInt;
r: Rect;
poly: Handle;
stars: Array[0..19] of Star;
begin
graphics(320);
clearScreen(black);
hideCursor;
tick := getTick;
{ Draw spaceship }
setSolidPenPat(7);
setRect(r, 0, 93, 25, 97);
paintOval(r);
poly := openPoly;
moveTo(10, 91);
lineTo(30, 95);
lineTo(10, 99);
closePoly;
setSolidPenPat(4);
paintPoly(poly);
setSolidPenPat(5);
moveTo(8, 91);
line(8, 0);
moveTo(8, 98);
line(8, 0);
{ Setup stars }
for i := 0 to 19 do begin
stars[i].x := random mod 320;
stars[i].y := i * 10;
stars[i].speed := random mod 6 + 1;
end;
repeat
for i := 0 to 19 do begin
{ Erase stars }
setSolidPenPat(black);
moveTo(stars[i].x, stars[i].y);
line(0, 0);
{ Move stars }
stars[i].x := stars[i].x - stars[i].speed;
if stars[i].x < 0 then begin
stars[i].x := 319;
stars[i].speed := random mod 6 + 1;
end;
{ Draw stars }
setSolidPenPat(i mod 15 + 1);
moveTo(stars[i].x, stars[i].y);
line(0, 0);
end;
{ Draw fire }
if random > 0 then setSolidPenPat(9)
else setSolidPenPat(7);
moveTo(5, 94);
line(4, 0);
repeat until getTick > tick;
tick := tick + 1;
until button(0);
end.
Spaceship flying in star field.
This program teaches the use of array and record to create multiple objects. It uses array to generate many stars and animate them all at once at different speed. It also teaches how to use polygon to draw a shape.
You can see the Orca/Pascal here. Orca/Pascal version is written using Object Pascal, an object oriented extension of the Pascal language.
GSoft BASIC star field
TYPE STAR
X AS INTEGER
Y AS INTEGER
SPEED AS INTEGER
END TYPE
DIM STARS(15) AS STAR
! Setup stars
HGR
FOR I = 1 TO 15
STARS(I).X = RND (1) * 320
STARS(I).Y = I * 12
STARS(I).SPEED = RND (1) * 6 + 1
NEXT
DO
FOR I = 1 TO 15
! Erase star
HCOLOR= 0
HPLOT STARS(I).X, STARS(I).Y
! Draw star
STARS(I).X = STARS(I).X - STARS(I).SPEED
IF STARS(I).X < 0 THEN STARS(I).X = 319
HCOLOR= I
HPLOT STARS(I).X, STARS(I).Y
NEXT
LOOP