'===========================================================================
' Subject: PB ROTATE & SMOOTH EFFECT         Date: 05-01-97 (22:01)       
' Author:  Angelo Ken Pesce                  Code: PB                     
' Origin:  ken@uniserv.uniplan.it          Packet: GRAPHICS.ABC
'===========================================================================
' APSOFTWARE 1997
' POWERBASIC ROTATE+SMOOTH EFFECT TEST

' ------------------------------------------------------------
' This is only a test version
' to do list:

' I have to build a new set of points (including mirrored negative points...)
' I have to use shift left instead of constant mult (*320)
' I have to make a better smooth effect
' ------------------------------------------------------------

$OPTIMIZE SPEED
$CPU 80386
$FLOAT PROCEDURE
$LIB ALL OFF

' ------------------------------------------------------------
' Some math constants
pi = 3.1415

' Multiplication factor
mult = 20

' Number of points in data
pts = 26

' Look up tables
DIM r(pts)
DIM alpha(pts)

' Points x,y arrays
DIM xp(pts)
DIM yp(pts)

' TEST DATA (X,Y)
DATA 3,1,4,1,1,2,2,2,3,2,4,2,5,2,6,2,1,3,2,3,5,3,6,3,1,4,2,4,3,4,4,4,5,4
data 6,4,1,5,2,5,5,5,6,5,1,6,2,6,5,6,6,6
' ------------------------------------------------------------



' ------------------------------------------------------------

FOR i = 1 TO pts
READ b, a
xp(i) = a * mult
yp(i) = b * mult
NEXT

FOR i = 1 TO pts
r(i) = SQR((xp(i) ^ 2) + (yp(i) ^ 2))
NEXT

FOR i = 1 TO pts
alpha(i) = ATN(yp(i) / xp(i))
NEXT
' ------------------------------------------------------------


GOTO maincode


' ------------------------------------------------------------
' Subroutine: RotatePoints(D,COL)
rotp:
FOR k = 1 TO pts
angle = alpha(k) + d
radius = r(k)
x = INT(radius * SIN(angle))
y = INT(radius * COS(angle))
IF x < 0 OR y < 0 THEN GOTO skipd

' SLOW MULT     --- TO BE REPLACED using shift left...---
yy=y*320
POKE (yy + x), 63

poke ((y-1)*320+x),63
poke ((y+1)*320+x),63
poke (yy+x+1),63
poke (yy+x-1),63

skipd:
NEXT
RETURN

' Subroutine: Waitkpress
wkp:
DO: LOOP UNTIL INKEY$ <> ""
RETURN

' Subroutine: Flame
flm:
for y=0 to 198
ym=y*320
ym2=(y+1)*320
for x=0 to 319
ymm=ym+x
cl%=peek(ymm+1)+peek(ymm)
if cl%=0 then goto skpf else cl%=cl%+peek(ymm-1)+peek(ym2+x)
shift right cl%,2
poke (ym+x),cl%
skpf:
next
next
return
' ------------------------------------------------------------


maincode:

! mov ax,&h13
! int &h10

OUT &H03c8,0
for i=0 to 63
out &h03c9,i
out &h03c9,0
out &h03c9,0
next

DEF SEG = &HA000
do
FOR d = 0 TO pi*2 STEP .05
GOSUB rotp
gosub flm
NEXT
loop
END