'===========================================================================
' Subject: 3D STARFIELD SIMULATION           Date: 06-09-96 (20:50)       
' Author:  John Wantland                     Code: QB, QBasic, PDS        
' Origin:  kwantlan@coffey.com             Packet: GRAPHICS.ABC
'===========================================================================
REM starfield
n = 50       'number of stars
DIM y(n)
DIM x(n)
DIM s(n)
DIM c(n)
DIM x1(n)
DIM y1(n)
DIM c1(n)
DIM s1(n)
RANDOMIZE TIMER
SCREEN 12: CLS
FOR i = 1 TO n
x(i) = INT(RND * 640 + 1)
y(i) = INT(RND * 480 + 1)
s(i) = INT(RND * 5 + 1)
s1(i) = INT(RND * 5 + 1)
x1(i) = INT(RND * 640 + 1)
y1(i) = INT(RND * 480 + 1)
IF s1(i) <= 3 THEN c1(i) = 8
IF s1(i) = 4 THEN c1(i) = 7
IF s1(i) = 5 THEN c1(i) = 15
IF s(i) <= 3 THEN c(i) = 8
IF s(i) = 4 THEN c(i) = 7
IF s(i) = 5 THEN c(i) = 15
NEXT i
DO
FOR i = 1 TO n
PSET (x(i), y(i)), 0
PSET (x1(i), y1(i)), 0
x(i) = x(i) - s(i)
x1(i) = x1(i) - s1(i)
IF x(i) <= 1 THEN GOSUB 2
IF x1(i) >= 640 THEN GOSUB 3
PSET (x(i), y(i)), c(i)
PSET (x1(i), y1(i)), c1(i)
a$ = INKEY$: IF a$ <> "" THEN END
NEXT i
LOOP
2 x(i) = 640
y(i) = INT(RND * 480 + 1)
RETURN
3 x1(i) = 1
y1(i) = INT(RND * 480 + 1)
RETURN