Code: Select all
rem True 3D Stars
rem iPhone 6 Plus / iOS 8.4 b3 / 4.8
rem Enjoy...
'It's a nice interactive 3D starfield Demonstration
'and this is a true 3D starfield.. The others I did
'before never had rotations This looks nicer somehow
gosub initialize
'umode = -1 ' 1 on -1 off
mmm=16384
loop:
refresh off
graphics clear 10/255,10/255,30/255
'fill color 10/255,10/255,30/255
'fill tri 0,0, sw,sh, 0,sh
'fill tri 0,0, sw,sh, sw,0
gosub rotate
gosub draw
gosub display
refresh on
goto loop
display:
'The interacitve bit. Also does text stuff.
xin=1
yin=1
zin=2
if umode=1 then
if accel_x()<0 then xin=-5
if accel_y()>0 then yin=5
if accel_y()<0 then yin=-5
if accel_x()>0 then xin=5
if accel_z()>0 then zin=-5
if accel_z()<0 then zin=5
draw text "THE INTERACTIVE STARFIELD DEMO" at 0,30
draw text "USER CONTROL MODE : ON! PRESS TURN OFF" at 0,50
draw text "TRY TILTING YOUR IDEVICE!" at 0,70
if xin>0 then xin=xin-1
if xin<0 then xin=xin+1
if yin>0 then yin=yin-1
if yin<0 then yin=yin+1
if zin>0 then zin=zin-1
if zin<0 then zin=zin+1
end if
draw text mid$(s$,p,67) at scx,sh-20
scx=scx-2
if scx<-10 then
scx=scx+10
p=p+1
if p>len(s$)-1 then p=0
end if
return
draw:
'Draw The object
b=1
for a=1 to polys
sz=((80-tz(a))/14)
fill color sz/255,sz/255,(sz*25)/255
fill rect tx(a)-sz,ty(a)-sz to tx(a)+sz,ty(a)+sz
fill color 50/255,250/255,250/255
fill rect tx(a)-2,ty(a)-2 to tx(a)+2,ty(a)+2
next a
return
rotate:
'Rotate And Scale Each Point Store Result
for a=1 to polys
z(a)=z(a)+2
if z(a)>50 then z(a)=z(a)-100
x1=x(a)
y1=y(a)
z1=z(a)
'X,Y,Z rotations
xx=x1
yy=y1*cs(xr)+z1*sn(xr)
zz=z1*cs(xr)-y1*sn(xr)
y1=yy
x1=xx*cs(yr)-zz*sn(yr)
z1=xx*sn(yr)+zz*cs(yr)
zz=z1
xx=x1*cs(zr)-y1*sn(zr)
yy=x1*sn(zr)+y1*cs(zr)
'Apply Perspective
xx=size*(xx/((zz/70)+1))+sw/2
yy=size*(yy/((zz/70)+1))+sh/2
tx(a)=xx
ty(a)=yy
tz(a)=zz
next a
xr=xr+xin
yr=yr+yin
zr=zr+zin
if xr>=720 then xr=xr-720
if yr>=720 then yr=yr-720
if zr>=720 then zr=zr-720
if xr<=0 then xr=xr+720
if yr<=0 then yr=yr+720
if zr<=0 then zr=zr+720
return
initialize:
'Open Gfx Screen
graphics
sw=screen_width()
sh=screen_height()
s$=" "
s$=s$&" The interactive starfield demo.. "
s$=s$&"This one uses a true 3D starfield code. The other "
s$=s$&"basic ones you have seen are silly... I wanted "
s$=s$&"to see if it could be achieved properly."
s$=s$&" try the interactive mode. Enjoy!"
p=0
scx=0
'Define the necessary variables
size=6 ' how big do you want it?
pi=3.1415
polys=70 ' The amount of Stars.
dim x(polys+1) ' Original X co-ordinate store
dim y(polys+1) ' Original Y co-ordinate store
dim z(polys+1) ' Original Z co-ordinate store
dim tx(polys+1) ' Transformed X co-ordinate store
dim ty(polys+1) ' Transformed Y co-ordinate store
dim tz(polys+1) ' Transformed Z co-ordinate store
umode=-1 ' user control mode on/off 1/0.
mmm=0.0
'Define Sine Tables
dim cs(721)
dim sn(721)
for ang=0 to 720
cs(ang)=cos(ang*(pi/360))
sn(ang)=sin(ang*(pi/360))
next ang
'Create Starfield
mmm=-25
for a=1 to polys
x(a)=-40+rnd(80)
y(a)=-40+rnd(80)
z(a)=mmm
mmm=mmm+100/polys
next a
return
