'===========================================================================
' Subject: FLUORESCENT CONES                 Date: 03-18-98 (21:30)       
' Author:  Wayne Wallace                     Code: QB, QBasic, PDS        
' Origin:  www.qbasic.com                  Packet: GRAPHICS.ABC
'===========================================================================
'Title: Fluorescent Cones
'File: CONES.BAS
'Source: Computer Doodles: (ISBN 1-887112-01-4)
'Date: May 1996
'Author: Wayne Wallace
'Send all comments to: Wayne Wallace, 3129 25th St. #212, Columbus, IN 47203

'*********************** Please Note *******************************
'The program line "speed = 10" controls the speed of the program. 
'Adjust this value to match the program to the speed of your computer.
'To stop the program while it is running, press any key.
'********************************************************************

'How it Works:

'Three different colored circles are drawn at the starting coordinates
'of (50, 50), but each circle is slightly out of phase by one row. The
'cones are made by increasing and decreasing the size of the circles as
'they move diagonally across the screen. 

SCREEN 12
DEFINT A-Z
speed = 10
RANDOMIZE TIMER

'Select plaid colors-for backdrop---
k1 = 4: k2 = 8: k3 = 0: cc = 31: aa = 480
b2 = 480: d2 = 480: i1 = 8: i2 = 8
GOSUB backdrop
'--------------
a = 50: B = 50: c = 25
d1 = 1: d2 = 1: d3 = 1: d4 = 1
k1 = 10: k2 = 13: k3 = 0
  FOR m = 1 TO 9463
    IF INKEY$ <> "" THEN END
    CIRCLE (a, B - 1), c, k1
    CIRCLE (a, B), c, k2
    CIRCLE (a, B + 1), c, k3
    a = a + d1: B = B + d2
    IF a > 620 THEN d1 = -1: k1 = INT(RND * 7) + 9
    IF a < 6 THEN d1 = 1: k3 = 0
    IF B > 480 THEN d2 = -1: k2 = INT(RND * 7) + 9
    IF B < 6 THEN d2 = 1: k1 = INT(RND * 7) + 9
    IF k2 = 11 THEN k1 = 15
    IF k1 = 11 THEN k1 = 12
    IF m > 4283 THEN
    c = c + d3
    'cone effect
    IF c > 50 THEN d3 = -1: vx = 2.5
    IF c < 1 THEN d3 = 1
    IF c < 10 THEN vx = 4
    END IF
      FOR delay = 1 TO speed
      NEXT delay
    NEXT m
    SLEEP 3
'clear the screen in white
k1 = 0
GOSUB clswipe
END

clswipe:
'---black cls-----------------
o1 = 640: p1 = -1: o2 = -1: p2 = 480
f1 = 1: f2 = 1
FOR m = 1 TO 325
IF INKEY$ <> "" THEN END
LINE (o1, p1)-(o2, p2), k1, B
o1 = o1 - f1: o2 = o2 + f2
FOR zz = 1 TO 20 * spd
NEXT zz
NEXT m
PALETTE
RETURN

backdrop:
LINE (0, 0)-(640, aa), k1, BF
a1 = 4: b1 = 0: a2 = 636
c1 = 0: d1 = 0: c2 = 640
FOR m = 1 TO 40
LINE (a1, b1)-(a2, b2), k2, B
a1 = a1 + 8
a2 = a2 - 8
NEXT m
FOR m = 1 TO cc
LINE (c1, d1)-(c2, d2), k3, B
d1 = d1 + i1
d2 = d2 - i2
NEXT m
RETURN