Fireworks

[Steven Picard]

This was originally written by Fletchie and modified by Boris (where are you?)  I got this from the off-line forum (any chance of making it available again since that info is now useful?) The code worked like a charm right away:

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autodefine "off"
def fps,ext:int
def t,n,nn:int
type pixel
   def x:float
   def y:float
   def c:int
endtype
const total=10000
def test[total]:pixel
def vx[total]:float
def vy[total]:float
def an,x,y:float
createscreen 640,480,32
for t=1 to 200   /* A bit of a delay for screen warm-up */
   fillscreen 0
   flip
next t
nn=1001
do
   fillscreen 0
   if nn>20
      nn=0
      gosub set_pixels
   endif
   nn=nn+1
   WritePixelGroupFast(test,total,backbuffer)
   for t=0 to total-1   /* Add the x,y velocities... */
   vx[t]=vx[t]*.995
   vy[t]=vy[t]+.05
      test[t].x=test[t].x+vx[t]
      test[t].y=test[t].y+vy[t]
   next t
   writetext 0,0,str$(fps)
   fps = flip
until keydown(1)
end
sub set_pixels
def start:int
def force:float
ext=rand(10,400)
select 1
   case ext<100:fillscreen 0x111111
   case ext<300:fillscreen 0x222222
   case ext<370:fillscreen 0x333333
   default:fillscreen 0x999999
endselect
start=rand(0,total-ext)
x=rand(0,640)
y=rand(0,480)
force=rand(1,4)*1000
for n=start to start+ext
   test[n].x=x
   test[n].y=y
   test[n].c=rgb(rand(0,255),rand(0,255),rand(0,255))
   an=rand(0,35999)/100f
   vx[n]=fsind(an)*rand(50,5000)/force
   vy[n]=fcosd(an)*rand(50,5000)/force
next n
return
endsub
def bpointer,bpitch:int
def pp:pointer
def pcount:int
sub WritePixelGroupFast(p:pointer,qty:int,w:window)
   lockbuffer w
   bpointer=getbufferpointer()
   bpitch=getbufferpitch()
   pp=p
   pcount=qty
_asm
   push ebp
   push ebp
   mov ebp,[$pp]
   mov ecx,[$pcount]
   mov esi,[$bpitch]
   mov edi,[$bpointer]
another:
;   mov ebx,[ebp+72] ; Enabling this increases fps slightly (kinda pre-caching),  needs a bit of extra space at the end of an array
   fld dword [ebp]
   fistp dword [esp]
   mov ebx,[esp]
   cmp ebx,639 ; one less than screen width
   jg nextone
   test ebx,0x8000000
   jnz nextone
   fld dword [ebp+4]
   shl bx,2
   mov eax,esi
   fistp dword [esp]
   cmp dword [esp],479 ; one less than screen height
   jg nextone
   test dword [esp],0x80000000
   jnz nextone
   mul dword [esp]
   add eax,ebx
   add eax,edi
   mov ebx,[ebp+8]
   mov dword [eax],ebx
nextone:
   add ebp,12
   loop another
   pop ebp
   pop ebp
_endasm
   unlockbuffer w
   return
endsub