'===========================================================================
' Subject: BIDIRECTIONAL LINE PLASMA         Date: 08-02-97 (20:02)       
' Author:  Davey W. Taylor                   Code: QB, QBasic, PDS        
' Origin:  audio.squad@mailbox.swipnet.se  Packet: GRAPHICS.ABC
'===========================================================================
'ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ--ÄÄÄ--Ä -ù  ù
'³                   ** PLASMA EFFECT **
'³                Created by Davey W Taylor
'³
'³ Please mention my name if you use this code in your program!
'ÀÄÄÄÄÄ--ÄÄù-  ù   ù
' ** If you have any comments / suggestions / questions, my email is: **
' ** audio.squad@mailbox.swipnet.se                                   **

DECLARE SUB setPal (Attr%, Red%, Green%, Blue%)
DECLARE SUB getPal (Attr%, Red%, Green%, Blue%)
SCREEN 13                           'Gee...

FOR o% = 0 TO 63                    'Set a rainbow palette
 setPal n% + o%, o% - 1, 0, 63
NEXT o%
n% = n% + 64
FOR o% = 0 TO 63
 setPal n% + o%, 63, o% - 1, 63 - o%
NEXT o%
n% = n% + 64
FOR o% = 0 TO 63
 setPal n% + o%, 63, 63 - o%, 0
NEXT o%
n% = n% + 64
FOR o% = 0 TO 63
 setPal n% + o%, 63 - o%, 0, o% - 1
NEXT o%
setPal 0, 0, 0, 0                   'Fix missed colors
setPal 64, 63, 0, 63
setPal 128, 63, 63, 0
setPal 192, 63, 0, 0

FOR n% = 0 TO 319 STEP 2            'Draw the bidirectional pattern
 c% = c% + 1
 IF c% = 0 THEN c% = 1
 LINE (n%, 0)-(n%, 199), c%
 LINE (319 - n%, 0)-(319 - n%, 199), c%
NEXT n%
LINE (0, 0)-(319, 19), 0, BF        'Clear the sides
LINE (0, 180)-(319, 199), 0, BF
LINE (0, 0)-(29, 199), 0, BF        'Clear top and bottom
LINE (290, 0)-(319, 199), 0, BF
LINE (29, 19)-(290, 180), 1, B      'Draw a border
LOCATE 1, 9
PRINT "Plasma by Davey W Taylor"

DO
 WAIT &H3DA, 8                      'Wait for screen retrace
 getPal 1, rr%, gr%, br%    'Rotate ' - the safest way to make
 FOR n% = 2 TO 255          ' - the ' - a delay in a program
  getPal n%, r%, g%, B%     ' - palette
  setPal n% - 1, r%, g%, B%
 NEXT n%
 setPal 255, rr%, gr%, br%
LOOP WHILE INKEY$ = ""

SUB getPal (Attr%, Red%, Green%, Blue%)
OUT &H3C7, Attr%
OUT &H3C8, Attr%
Red% = INP(&H3C9)
Green% = INP(&H3C9)
Blue% = INP(&H3C9)
END SUB

SUB setPal (Attr%, Red%, Green%, Blue%)
OUT &H3C7, Attr%
OUT &H3C8, Attr%
OUT &H3C9, Red%
OUT &H3C9, Green%
OUT &H3C9, Blue%
END SUB