rem Start of BASIC! Program

FN.DEF bezier(p1x,p1y,s1x,s1y,s2x,s2y,p2x,p2y)

n=(HYPOT(s1x-p1x,s1y-p1y)+ HYPOT(s2x-s1x,s2y-s1y)+ HYPOT(p2x-s2x,p2y-s2y))/20
ox=p1x
oy=p1y
FOR i=0 TO 1 STEP 1/n
x1=p1x+(s1x-p1x)*i
y1=p1y+(s1y-p1y)*i
x2=s1x+(s2x-s1x)*i
y2=s1y+(s2y-s1y)*i
x3=s2x+(p2x-s2x)*i
y3=s2y+(p2y-s2y)*i
x4=x1+(x2-x1)*i
y4=y1+(y2-y1)*i
x5=x2+(x3-x2)*i
y5=y2+(y3-y2)*i
x=x4+(x5-x4)*i
y=y4+(y5-y4)*i

GR.LINE vd,ox,oy,x,y
ox=x
oy=y
NEXT i
GR.LINE vd,ox,oy,p2x,p2y

FN.END

FN.DEF bezier1(p1x,p1y,s1x,s1y,s2x,s2y,p2x,p2y)

n=(HYPOT(s1x-p1x,s1y-p1y)+ HYPOT(s2x-s1x,s2y-s1y)+ HYPOT(p2x-s2x,p2y-s2y))/20
ox=p1x
oy=p1y
FOR i=0 TO 1 STEP 1/n
x1=p1x+(s1x-p1x)*i
y1=p1y+(s1y-p1y)*i
x2=s1x+(s2x-s1x)*i
y2=s1y+(s2y-s1y)*i
x3=s2x+(p2x-s2x)*i
y3=s2y+(p2y-s2y)*i
x4=x1+(x2-x1)*i
y4=y1+(y2-y1)*i
x5=x2+(x3-x2)*i
y5=y2+(y3-y2)*i
x=x4+(x5-x4)*i
y=y4+(y5-y4)*i

GR.LINE vd,ox,oy,x,y
ox=x
oy=y
NEXT i
GR.LINE vd,ox,oy,p2x,p2y

FN.END
!test
DIM l[8]
GR.OPEN 255,255,255,255,0,1
GR.SCREEN sx,sy
do
gr.touch yyy,x,y
until yyy
sx=x
sy=y
x1=INT(sx/10*1)
y1=INT(sy/20*8)
x2=INT(sx/10*6)
y2=INT(sy/20*9)
x3=INT(sx/10*4)
y3=INT(sy/20*13)
x4=INT(sx/10*8)
y4=INT(sy/20*10)

x5=INT(sx/10*2)
y5=INT(sy/20*16)
x6=INT(sx/10*8)
y6=INT(sy/20*17)
x7=INT(sx/10*9)
y7=INT(sy/20*19)
x8=INT(sx/10*7)
y8=INT(sy/20*20)

DO
GR.CLS
GR.TEXT.SIZE sy/30
GR.TEXT.ALIGN 2
GR.SET.STROKE 1

GR.COLOR 255,255,0,0,1
GR.CIRCLE vd,x1,y1,sx/100

GR.COLOR 255,0,255,0,1
GR.CIRCLE vd,x2,y2,sx/100

GR.COLOR 255,0,0,255,1
GR.CIRCLE vd,x3,y3,sx/100

GR.COLOR 255,255,255,0,1
GR.CIRCLE vd,x4,y4,sx/100

GR.COLOR 255,0,255,255,1
GR.LINE gol1,x1,y1,x2,y2
GR.LINE gol2,x3,y3,x4,y4

GR.COLOR 255,0,0,0,1
GR.SET.STROKE 1
GR.LINE gol3,x1,y1,x2,y2
GR.LINE gol4,x3,y3,x4,y4

GR.SET.STROKE 5
bezier(x1,y1,x2,y2,x3,y3,x4,y4)
bezier1(x4,y4,x5,y5,x6,y6,x7,y7)
GR.RENDER

GR.TOUCH tt,tx,ty
IF tt&!ott THEN
l[1]=HYPOT(tx-x1,ty-y1)
l[2]=HYPOT(tx-x2,ty-y2)
l[3]=HYPOT(tx-x3,ty-y3)
l[4]=HYPOT(tx-x4,ty-y4)


l[5]=HYPOT(tx-x5,ty-y5)
l[6]=HYPOT(tx-x6,ty-y6)
l[7]=HYPOT(tx-x7,ty-y7)
l[8]=HYPOT(tx-x8,ty-y8)

ARRAY.MIN amin,l[]
ARRAY.SEARCH l[],amin,p

ELSEIF tt&ott THEN
IF p=1 THEN
x1=INT(tx/20)*20
y1=INT(ty/20)*20
ELSEIF p=2 THEN
x2=INT(tx/20)*20
y2=INT(ty/20)*20
ELSEIF p=3 THEN
x3=INT(tx/20)*20
y3=INT(ty/20)*20
ELSEIF p=4 THEN
x4=INT(tx/20)*20
y4=INT(ty/20)*20
ELSEIF p=5 THEN
x5=INT(tx/20)*20
y5=INT(ty/20)*20
ELSEIF p=6 THEN
x6=INT(tx/20)*20
y6=INT(ty/20)*20
ELSEIF p=7 THEN
x7=INT(tx/20)*20
y7=INT(ty/20)*20
ELSEIF p=8 THEN
x8=INT(tx/20)*20
y8=INT(ty/20)*20
ENDIF
ELSE
PAUSE 100
ENDIF
ott=tt
UNTIL 0