'===========================================================================
' Subject: BOUNCING WORM                     Date: 04-14-96 (14:40)       
' Author:  Andrew Jones                      Code: QB, QBasic, PDS        
' Origin:  FidoNet QUIK_BAS Echo           Packet: GRAPHICS.ABC
'===========================================================================
'Here's a trippy VGA screensaver of a WORM moving on a VGA background.  He
'moves and is animated...  One problem is he starts leaving black spots
'after awhile, you'll see it

DECLARE SUB animate (qq%)
DEFINT A-Z
SCREEN 13
RANDOMIZE TIMER
d = 8
v = 1
q = 1
x = 160
y = 100
xd = INT(RND * 4) + 2
yd = INT(RND * 4) + 2
IF INT(RND * 10) > 5 THEN xd = -xd ELSE xd = ABS(xd)
IF INT(RND * 10) > 5 THEN yd = -yd ELSE yd = ABS(yd)
FOR t = 0 TO 100
LINE (0, t)-(319, t), 200 - t
LINE (0, 200 - t)-(319, 200 - t), t
 
LINE (t, t)-(319 - t, t), t
LINE (t, 200 - t)-(319 - t, 200 - t), 200 - t
NEXT
DO
IF INT(RND * 30) + 1 = 15 AND xd < 0 THEN xd = xd - 1
IF xd = -1 THEN xd = 2
IF xd = -6 THEN xd = -5
IF INT(RND * 30) + 1 = 15 AND xd > 0 THEN xd = xd + 1
IF xd = 1 THEN xd = -2
IF xd = 6 THEN xd = -5
IF INT(RND * 30) + 1 = 15 AND yd > 0 THEN yd = yd + 1
IF yd = 1 THEN yd = -2
IF yd = -6 THEN yd = -5
IF INT(RND * 30) + 1 = 15 AND yd < 0 THEN yd = yd - 1
IF yd = -1 THEN yd = 2
IF yd = 6 THEN yd = 5
FOR t = 1 TO 8
CIRCLE (x, y), 15 - t, q + t
CIRCLE (x + 1, y), 15 - t, q + t
NEXT
x = x + xd
y = y + yd
IF x < 3 AND xd < 0 THEN xd = ABS(xd)
IF x > 316 AND xd > 0 THEN xd = -xd
IF y < 3 AND yd < 0 THEN yd = ABS(yd)
IF y > 196 AND yd > 0 THEN yd = -yd
q = q + 1
IF q = 255 THEN q = 1
v = v + d
IF v = 400 THEN d = -8
IF v = 0 THEN d = 8
animate v
LOOP
 
SUB animate (qq)
OUT &H3C8, 1
FOR t = 1 TO 255
OUT &H3C9, (t + qq)
OUT &H3C9, (t + qq) \ 2
OUT &H3C9, (t + qq) \ 4
NEXT
END SUB