'===========================================================================
' Subject: ROTATING PLANETS                  Date: 05-15-97 (10:04)       
' Author:  Davey W. Taylor                   Code: QB, QBasic, PDS        
' Origin:  audio.squad@mailbox.swipnet.se  Packet: GRAPHICS.ABC
'===========================================================================
'Rotating PLANETS
'Davey W Taylor
'audio.squad@mailbox.swipnet.se

'--- setup ---
moonspin% = 16
earthspin% = 4
yflip% = 0
'-- program --
pi = 3.141593
a% = 1
yflip% = earthspin% + yflip%
DO
SWAP a%, v%
SCREEN 9, , a%, v%
WINDOW SCREEN (1, 1)-(640, 350)
WAIT &H3DA, 8
CLS
d% = (d% + earthspin%) MOD 360
r = d% * (pi / 180)
di% = (di% + yflip%) MOD 360
ri = di% * (pi / 180)
s = 10 + (COS(r) * 10)
x = 320 + (200 * SIN(r))
y = 175 + (50 * SIN(ri))
d2% = (d2% + moonspin%) MOD 360
r2 = d2% * (pi / 180)
s2 = 4 + (COS(r2) * 2) + (COS(r) * 2)
t = 50 + (25 * COS(r))
x2 = x + (t * SIN(r2))
y2 = y + (4 * COS(r2))
IF (10 * COS(r)) >= 0 THEN
CIRCLE (320, 175), 100, 14
PAINT (320, 175), 14, 14
END IF
IF (10 * COS(r2)) <= 0 THEN
CIRCLE (x2, y2), s2, 6
PAINT (x2, y2), 6, 6
END IF
CIRCLE (x, y), s, 9
PAINT (x, y), 9, 9
IF (10 * COS(r2)) > 0 THEN
CIRCLE (x2, y2), s2, 6
PAINT (x2, y2), 6, 6
END IF
IF (10 * COS(r)) < 0 THEN
CIRCLE (320, 175), 100, 14
PAINT (320, 175), 14, 14
END IF
LOOP UNTIL INKEY$ <> ""