'===========================================================================
' Subject: FLEXIBLE RASTER DISTANCE          Date: 05-28-97 (14:06)       
' Author:  Frank W. Zammetti                 Code: QB, QBasic, PDS        
' Origin:  fzammett@fpsserv.com            Packet: GRAPHICS.ABC
'===========================================================================
   SCREEN 0: CLS: COLOR 2: PRINT
   PRINT "This is a little effect that I did originally about 10 years ago no the C64"
   PRINT "that I ported over to the PC.  It was a cheat back then, and it still is!"
   PRINT "This is called (F)lexible (R)aster (D)istance, a relative of (F)lexible"
   PRINT "(L)ine (D)istance, but while FLD was a real technique, this is a fake that"
   PRINT "approximates what FRD would look like if it were actually possible!"
   PRINT: PRINT: COLOR 15
   PRINT "PRESS ANY KEY TO BEGIN..."
   LOCATE 22,1: COLOR 12
   PRINT "(C)opyright 1997 by Frank W. Zammetti": PRINT
   PRINT "Use is as you wish... But please give me credit somewhere!";
   DO WHILE INKEY$ = "": LOOP
	CLEAR: DEFINT a-z: SCREEN 12: CLS
   DIM FieldCols(100), FieldDist(100): GOSUB ReadCols: GOSUB ReadDistances

MainLoop:
   WAIT &h3da, 8
   FOR z = 1 TO 1000: NEXT z
   WAIT &h3da, 8
   ScanLine = 60: GOSUB DisplayField
	IF INKEY$ <> "" THEN GOTO ByeByeNow
   y = FieldDist(1)
   FOR z = 1 TO (FDS - 2): FieldDist(z) = FieldDist(z + 1): NEXT z
   FieldDist(FDS - 1) = y
   GOTO MainLoop

DisplayField:
	z = ScanLine
   y = 1

DisplayFieldLoop:
	x = FieldDist(y)
   IF x = -1 THEN RETURN
   IF x = 0 THEN GOTO DoColor
   FOR w = 1 TO x: LINE (1, z) - (640, z), 0: z = z + 1: NEXT w

DoColor:
	x = FieldCols(y)
   IF x = -1 THEN RETURN
   LINE (1, z) - (640, z), x: z = z + 1: y = y + 1: GOTO DisplayFieldLoop

ReadCols:
	y = 1

ReadColsLoop:
	READ z: FieldCols(y) = z
   IF z = -1 THEN GOTO ReadColsAllDone
   y = y + 1: GOTO ReadColsLoop

ReadColsAllDone:
	FCS = y: RETURN

ReadDistances:
	y = 1

ReadDistancesLoop:
	READ z: FieldDist(y) = z
   IF z = -1 THEN GOTO ReadDistancesAllDone
   y = y + 1: GOTO ReadDistancesLoop

ReadDistancesAllDone:
	FDS = y: RETURN

FieldColsData:
	data 4,4,4,4,12,12,12,14,14,15,14,14,12,12,12,4,4,4,4
   data 1,1,1,1,9,9,9,1,1,15,1,1,9,9,9,1,1,1,1
   data 2,2,2,2,10,10,10,11,11,15,11,11,10,10,10,2,2,2,2,-1

FieldDistancesData:
	data 0,1,2,3,4,5,6,7,8,9,10,11,12,11,10,9,8,7,6,5,4,3,2,1,0
   data 1,2,3,4,5,6,7,8,9,10,9,8,7,6,5,4,3,2,1,0
   data 1,2,3,4,5,6,5,4,3,2,1,1,1,-1

ByeByeNow:
	SCREEN 0: CLS: PRINT "Goodbye!...": PRINT: PRINT
   PRINT "Frank W. Zammetti (fzammett@fpsserv.com)"
   PRINT: PRINT: PRINT: END