'===========================================================================
' Subject: CIRCULAR PLASMA EFFECT            Date: 03-06-97 (15:24)       
' Author:  Angelo Ken Pesce                  Code: QB, PDS                
' Origin:  ken@uniserv.uniplan.it          Packet: GRAPHICS.ABC
'===========================================================================
DECLARE SUB initp ()
DECLARE SUB init ()
' ANGELO KEN PESCE 1997
' COLOR PLASMA EFFECT v4
' Email: ken at uniserv.uniplan.it
' LOAD THIS PROGRAM USING QBX /AH OR QB /AH
' WATCH THIS: IT's 160x100 but using different colors it looks like 320x200


' $DYNAMIC
DEFINT A-Z


' INITIALIZE CIRCLE ARRAY
DIM SHARED aps(250, 250)
CALL init
SCREEN 13


' PALETTE INIT
CALL initp

' PATTER 1 AND PATTER 2 CENTER and INITIAL MOVEMENT
xp1 = 80 + 20: yp1 = 50 + 20
xp2 = 80 - 20: yp2 = 50 - 20
xm1 = 1
ym1 = -1
xm2 = -1
ym2 = 1


DO
' FIRST HALF **************************************************************
DEF SEG = &HA000
FOR x = 1 TO 160
ax = x + 125
x1 = ax - xp1
x2 = ax - xp2
px = x * 2
FOR y = 1 TO 50
ay = y + 125

y1 = ay - yp1
' THOSE CHECKS ARE REMOVED TO INCREASE SPEED
'IF x1 < 1 OR x1 > 250 OR y1 < 1 OR y1 > 250 THEN col1 = 0: GOTO ex1
col1 = aps(x1, y1)
ex1:

y2 = ay - yp2
' THOSE CHECKS ARE REMOVED TO INCREASE SPEED
'IF x2 < 1 OR x2 > 250 OR y2 < 1 OR y2 > 250 THEN col2 = 0: GOTO ex2
col2 = aps(x2, y2)
ex2:

IF col1 > 0 AND col2 > 0 THEN GOTO rand1 ELSE col = col1 + col2

py = y * 2
POKE (py * 320 + px), col
POKE (py * 320 + px - 1), col + 32
POKE ((py - 1) * 320 + px), col + 16
POKE ((py - 1) * 320 + px - 1), col + 16
GOTO next1
rand1:
py = y * 2
POKE (py * 320 + px), 0
POKE (py * 320 + px - 1), 0
next1:
NEXT
NEXT

' SECOND HALF *************************************************************

DEF SEG = (&HA000 + &H7D0)

FOR x = 1 TO 160
ax = x + 125
x1 = ax - xp1
x2 = ax - xp2
px = x * 2
FOR y = 1 TO 50
ay = y + 125

y1 = ay - yp1 + 50
' THOSE CHECKS ARE REMOVED TO INCREASE SPEED
'IF x1 < 1 OR x1 > 250 OR y1 < 1 OR y1 > 250 THEN col1 = 0: GOTO ex3
col1 = aps(x1, y1)
ex3:

y2 = ay - yp2 + 50
' THOSE CHECKS ARE REMOVED TO INCREASE SPEED
'IF x2 < 1 OR x2 > 250 OR y2 < 1 OR y2 > 250 THEN col2 = 0: GOTO ex4
col2 = aps(x2, y2)
ex4:

IF col1 > 0 AND col2 > 0 THEN GOTO rand2 ELSE col = col1 + col2

py = y * 2
POKE (py * 320 + px), col
POKE (py * 320 + px - 1), col + 32
POKE ((py - 1) * 320 + px), col + 16
POKE ((py - 1) * 320 + px - 1), col + 16
GOTO next2
rand2:
py = y * 2
POKE (py * 320 + px), 0
POKE (py * 320 + px - 1), 0
next2:
NEXT
NEXT

DEF SEG
GOSUB setmov
LOOP UNTIL INKEY$ <> ""

END

setmov:
' LET THEM MOVE (I HAVE TO IMPROVE THIS ROUTINE!!!)
xp1 = xp1 + xm1
yp1 = yp1 + ym1
xp2 = xp2 + xm2
yp2 = yp2 + ym2
IF xp1 > 80 + 20 THEN xm1 = -1 ELSE IF xp1 < 80 - 20 THEN xm1 = 1
IF yp1 > 50 + 20 THEN ym1 = -1 ELSE IF yp1 < 50 - 20 THEN ym1 = 1
IF xp2 > 80 + 20 THEN xm2 = -1 ELSE IF xp2 < 80 - 20 THEN xm2 = 1
IF yp2 > 50 + 20 THEN ym2 = -1 ELSE IF yp2 < 50 - 20 THEN ym2 = 1
RETURN

REM $STATIC
SUB init

' I HAVE TO USE THIS "TRICK" IN ORDER TO USE INTEGERS

SCREEN 12
FOR i = 1 TO 180 STEP 16
FOR i1 = 1 TO 4
CIRCLE (125, 125), i + i1, i1 + ((180 - i) / 18)
CIRCLE (126, 125), i + i1, i1 + ((180 - i) / 18)
NEXT
FOR i1 = 1 TO 4
CIRCLE (125, 125), i + i1 + 4, (5 - i1) + ((180 - i) / 18)
CIRCLE (126, 125), i + i1 + 4, (5 - i1) + ((180 - i) / 18)
NEXT
NEXT

FOR x = 1 TO 250
FOR y = 1 TO 250
aps(x, y) = POINT(x, y)
NEXT
NEXT
END SUB

SUB initp
FOR i = 0 TO 15
PALETTE i, i * 4
NEXT
FOR i = 16 TO 31
PALETTE i, 256 * ((i - 16) * 2 + 7)
NEXT
FOR i = 32 TO 47
PALETTE i, 65536 * ((i - 32) * 4)
NEXT
END SUB