REM Start of BASIC! Program
rem demos for virtual reality VR goggles
rem by cterp 


starcount=100
DIM speed[starcount]
DIM birect[ starcount]
DIM radius[ starcount ]
DIM o[starcount]
DIM o2[starcount]
DIM newx[starcount]
DIM newx2[starcount]
DIM newy[starcount]
DIM oldx[starcount]
DIM oldx2[starcount]
DIM oldy[starcount]


fn.def r()
fn.rtn floor(rnd()*100)+80
fn.end

pi = ATAN(1) * 4
GR.OPEN 255, 0, 0, 0, 0
GR.ORIENTATION 0
GR.SCREEN mx, my


LIST.CREATE S,CLIST
LIST.ADD CLIST,"squares","stars","letters","quit"
do

dialog.select c,clist,"choose VR demo"
bkhit=0
gr.cls
IF C=1
gosub squares
ELSE IF C=2
gosub starfield
ELSE IF C=3
gosub alpha
ENDIF

until c=4

exit


alpha:

GR.COLOR 255, 255, 255, 255 ,1
GR.SET.STROKE 3 

LET midx = mx / 4 
LET midx2= 3*mx/4
LET midy = my / 2
LET maxrad = midx 
LET dd=60

WAKELOCK 3


FOR I = 1 TO starcount 
 LET speed[I] = (RND() + 0.1) / 100
 LET birect[I] = (RND() * 2 * pi)
 LET radius[I] = RND()
 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2
let newy[i]=SIN(birect[I]) *newrad+midy
GR.COLOR 255,r(),r(),r(),255

GR.SET.STROKE 2*rnd()+1

!GR.POINT o[i],newx[i],newy[i]
c$=chr$(ascii("a")+rnd()*26)
gr.text.size rnd()*30+5
gr.text.draw o[i],newx[i],newy[i],c$
gr.text.draw o2[i],newx2[i],newy[i],c$
!GR.POINT o2[i],newx2[i],newy[i]

 let oldx[i]=newx[i]:let oldx2[i]=newx2[i]:let oldy[i]=newy[i]

NEXT
GR.RENDER




DO


 FOR I=1 TO starcount 

  IF radius[I]>=1
   LET speed[I] = (RND() + 0.1) / 100
   LET birect[I] = RND() * (2 * pi)
   LET radius[I]= RND() / 300
  ELSE
   LET radius[I]+=speed[I]:LET newrad=radius[I]^2*maxrad
  ENDIF

 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2
 let newy[i]=SIN(birect[I])*newrad+midy

  GR.MOVE o[i],newx[i]-oldx[i],newy[i]-oldy[i]
  GR.MOVE o2[i],newx2[i]-oldx2[i],newy[i]-oldy[i]
 let oldx[i]=newx[i]
 let oldx2[i]=newx2[i]
 let oldy[i]=newy[i]
  GR.MODIFY o[i],"alpha",radius[I]*255
  GR.MODIFY o2[i],"alpha",radius[I]*255
 NEXT

 GR.RENDER 


UNTIL bkhit

return






starfield:
GR.COLOR 255, 255, 255, 255 ,1
GR.SET.STROKE 3 

LET midx = mx / 4 
LET midx2= 3*mx/4
LET midy = my / 2
LET maxrad = midx 
LET dd=40

WAKELOCK 3


FOR I = 1 TO starcount 
 LET speed[I] = (RND() + 0.3) / 100
 LET birect[I] = (RND() * 2 * pi)
 LET radius[I] = RND()
 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2
let newy[i]=SIN(birect[I]) *newrad+midy
GR.COLOR 255,r(),r(),r(),255
GR.SET.STROKE 1*rnd()+3
GR.POINT o[i],newx[i],newy[i]
GR.POINT o2[i],newx2[i],newy[i]
 let oldx[i]=newx[i]:let oldx2[i]=newx2[i]:let oldy[i]=newy[i]
NEXT
GR.RENDER


DO

 FOR I=1 TO starcount 

  IF radius[I]>=1
   LET speed[I] = (RND() + 0.3) / 100
   LET birect[I] = RND() * (2 * pi)
   LET radius[I]= RND() / 300
  ELSE
   LET radius[I]+=speed[I]:LET newrad=radius[I]^2*maxrad 
  ENDIF

 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2

 let newy[i]=SIN(birect[I])*newrad+midy

  GR.MOVE o[i],newx[i]-oldx[i],newy[i]-oldy[i]
  GR.MOVE o2[i],newx2[i]-oldx2[i],newy[i]-oldy[i]
 let oldx[i]=newx[i]
 let oldx2[i]=newx2[i]
 let oldy[i]=newy[i]
  GR.MODIFY o[i],"alpha",radius[I]*255
  GR.MODIFY o2[i],"alpha",radius[I]*255
 NEXT
 GR.RENDER 
UNTIL bkhit

return


squares:

GR.COLOR 255, 255, 255, 255 ,1
GR.SET.STROKE 3 
LET midx = mx / 4 
LET midx2= 3*mx/4
LET midy = my / 2
LET maxrad = midx 
LET dd=60

WAKELOCK 3


FOR I = 1 TO starcount 
 LET speed[I] = (RND() + 0.1) / 100
 LET birect[I] = (RND() * 2 * pi)
 LET radius[I] = RND()
 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2
let newy[i]=SIN(birect[I]) *newrad+midy
GR.COLOR 255,r(),r(),r(),255
GR.SET.STROKE 40*rnd()+5
GR.POINT o[i],newx[i],newy[i]
GR.POINT o2[i],newx2[i],newy[i]
let oldx[i]=newx[i]:let oldx2[i]=newx2[i]:let oldy[i]=newy[i]
NEXT
GR.RENDER


DO


 FOR I=1 TO starcount 

  IF radius[I]>=1
   LET speed[I] = (RND() + 0.1) / 100
   LET birect[I] = RND() * (2 * pi)
   LET radius[I]= RND() / 300
  ELSE
   LET radius[I]+=speed[I]:LET newrad=radius[I]^2*maxrad
  ENDIF

 let newx[i]=COS(birect[I])*newrad +midx
 let newx2[i]=COS((1+radius[i]/dd)*birect[I])*newrad +midx2
 let newy[i]=SIN(birect[I])*newrad+midy

  GR.MOVE o[i],newx[i]-oldx[i],newy[i]-oldy[i]
  GR.MOVE o2[i],newx2[i]-oldx2[i],newy[i]-oldy[i]
 let oldx[i]=newx[i]
 let oldx2[i]=newx2[i]
 let oldy[i]=newy[i]
  GR.MODIFY o[i],"alpha",radius[I]*255
  GR.MODIFY o2[i],"alpha",radius[I]*255

 NEXT

 GR.RENDER 


UNTIL bkhit
return

ongrtouch:
bkhit=1
gr.ongrtouch.resume



OnError:
GR.CLOSE
END