'===========================================================================
' Subject: BOUNCING TRIANGLE                 Date: 10-24-99 (09:33)       
' Author:  Michael Galos                     Code: QB, QBasic, PDS        
' Origin:  galvin@powerup.com.au           Packet: GRAPHICS.ABC
'===========================================================================
'By Michael Galos
'This is a bouncing triange program that I made years ago
'It's pretty simple and was one of my first programs ever.

SCREEN 13
pi = 3.141592654# / 180
s = 3000
r = 15
a = 160
b = 100
c = 32
d = 1
e = 1
1
FOR i = 1 TO 360
x1 = a + r * SIN(pi * i)
y1 = b + r * COS(pi * i)
x2 = a + r * SIN(pi * (i + 120))
y2 = b + r * COS(pi * (i + 120))
x3 = a + r * SIN(pi * (i - 120))
y3 = b + r * COS(pi * (i - 120))
LINE (x1, y1)-(x2, y2), c
LINE (x2, y2)-(x3, y3), c
LINE (x3, y3)-(x1, y1), c
a = a + d
b = b + e
IF a <= r THEN d = 1: GOSUB soun
IF a >= (319 - r) THEN d = -1: GOSUB soun
IF b <= r THEN e = 1: GOSUB soun
IF b >= (199 - r) THEN e = -1: GOSUB soun
FOR t = 1 TO s: NEXT t
LINE (x1, y1)-(x2, y2), 0
LINE (x2, y2)-(x3, y3), 0
LINE (x3, y3)-(x1, y1), 0
c = c + .1
IF c >= 103 THEN c = 32
NEXT i
GOTO 1
soun:
FOR u = 1 TO 12
SOUND 11700 * RND + 2137, .0229
NEXT u
RETURN