For i# = 0.0 To 1.0 Step 0.01
Print I
Next
WaitKey

Const scr_width = 800
Const scr_height = 600

Graphics scr_width,scr_height,0,2
SetBuffer BackBuffer()

Global timer1 = CreateTimer(60)
Global energie# = 0

Type Kugel
  Field x#,y#
  Field vx#,vy#
  Field tu#
  Field r#
   Field clr%
  Field lastcoll.Kugel
End Type

Type Kollision
  Field eins.Kugel
  Field zwei.Kugel
  Field time#
End Type

SeedRnd MilliSecs()

.reset

For k.Kugel = Each Kugel
  Delete k
Next

;Billiard
CreateKugel(250,300,0,0,15,255,0,0)
CreateKugel(224,316,0,0,15,255,0,0)
CreateKugel(224,284,0,0,15,255,0,0)
CreateKugel(198,331,0,0,15,255,0,0)
CreateKugel(198,300,0,0,15,255,0,0)
CreateKugel(198,269,0,0,15,255,0,0)
CreateKugel(172,347,0,0,15,255,0,0)
CreateKugel(172,316,0,0,15,255,0,0)
CreateKugel(172,284,0,0,15,255,0,0)
CreateKugel(172,253,0,0,15,255,0,0)
CreateKugel(500,300,-11,Rnd(-1.5,1.5),15,255,255,255)

;CreateKugel(250,300,0,0,20,255,0,0)
;CreateKugel(290,300,0,0,15,255,0,0)
;CreateKugel(325,300,0,0,5,255,0,0)
;CreateKugel(550,300,-3,0,15,255,255,255)

;CreateKugel(25,585,0,0,255,0,0)
;CreateKugel(75,585,0,0,255,0,0)
;CreateKugel(125,585,0,0,255,0,0)
;CreateKugel(175,585,0,0,255,0,0)
;CreateKugel(225,585,0,0,255,0,0)
;CreateKugel(275,585,0,0,255,0,0)
;CreateKugel(325,585,0,0,255,0,0)
;CreateKugel(375,585,0,0,255,0,0)
;CreateKugel(425,585,0,0,255,0,0)
;CreateKugel(475,585,0,0,255,0,0)
;CreateKugel(525,585,0,0,255,0,0)
;CreateKugel(575,585,0,0,255,0,0)
;CreateKugel(625,585,0,0,255,0,0)
;CreateKugel(675,585,0,0,255,0,0)
;CreateKugel(725,585,0,0,255,0,0)
;CreateKugel(775,585,0,0,255,0,0)
;CreateKugel(100,100,0,0,255,255,255)

Repeat
  If KeyHit(57) Goto reset
  WaitTimer(timer1)
  Update()
  Render()
  Flip
  Cls
  Until KeyHit(1)
End

Function Update()

  kollision_fertig = False
 
  energie# = 0.0
  tu# = 0.0
 
  For a.Kugel = Each Kugel
    a\tu# = 0.0
    a\lastcoll = Null
    energie# = energie# + 0.5 * ((a\vx)^2 + (a\vy^2))
  Next

  Repeat
 
  For a.Kugel = Each Kugel
    For b.Kugel = Each Kugel
      If (a <> b) And ((a\lastcoll <> b) Or (b\lastcoll <> a))
     
        d# = (a\x - b\x)
        e# = (a\vx - b\vx)
        n# = (a\y - b\y)
        u# = (a\vy - b\vy)
        qa# = (e^2 + u^2)
        qb# = 2*(d*e + n*u)
        qc# = (d^2 + n^2) - (a\r + b\r)^2
       
        w# = qb^2 - 4*qa*qc
        If (w# < 0) Then
          collision = False
        Else
          w# = Sqr(w#)
          t1# = (-qb + w) / (2*qa)
          t2# = (-qb - w) / (2*qa)
          tu# = a\tu
              t# = -1
          If ((t1 >= 0) And (t1 <= (1.0 - tu))) Then t# = t1
          If (((t2 >= 0) And (t2 <= (1.0 - tu))) And ((t# <> -1) Or (t2 < t1))) Then t# = t2
          If (t# <> -1) Then
            collision = True
               Else
                 collision = False
              End If
           End If
       
        If collision Then
          ;Kollision registrieren
          newcol.Kollision = New Kollision
          newcol\eins.Kugel = a
          newcol\zwei.Kugel = b
         
          Repeat
            anx# = a\x# + a\vx#*(t# - buffer#)
            any# = a\y# + a\vy#*(t# - buffer#)
            bnx# = b\x# + b\vx#*(t# - buffer#)
            bny# = b\y# + b\vy#*(t# - buffer#)
            If ((anx - bnx)^2 + (any - bny)^2) < (a\r + b\r)^2 Then
                 buffer# = buffer# + 0.000001
               Else
                 Exit
                End If
          Forever   
               
          newcol\time# = t# - buffer#
        End If
       
      End If
    Next
  Next
 
  ;Kleinstes suchen
 
  If (First Kollision = Null)
    kollision_fertig = True
  Else
 
    early.Kollision = First Kollision
    For col.Kollision = Each Kollision
      If (col\time# < early\time#) Then early = col
    Next
 
    a = early\eins
    b = early\zwei
    a\lastcoll = b
    b\lastcoll = a
 
    For k.Kugel = Each Kugel
      k\x# = k\x# + k\vx#*(early\time#)
      k\y# = k\y# + k\vy#*(early\time#)
    Next
    tu# = early\time#
 
    ;Kollidieren
 
    wi# = ((b\y# - a\y#) / (b\x# - a\x#))

    apx# = (wi * a\vy + a\vx) / (wi^2 + 1)
    asy# = a\vy - wi*apx
    bpx# = (wi * b\vy + b\vx) / (wi^2 + 1)
    bsy# = b\vy - wi*bpx
    anx# = bpx + a\vx - apx
    any# = b\vy - bsy + asy
    bnx# = apx + b\vx - bpx
    bny# = a\vy - asy + bsy
       
    a\vx# = anx#
    a\vy# = any#
    b\vx# = bnx#
    b\vy# = bny#
 
    For col.Kollision = Each Kollision
      Delete col
    Next
   
  End If
 
  Until (kollision_fertig)
 
  For a.Kugel = Each Kugel
    a\x# = a\x# + a\vx#*(1.0 - a\tu#)
    a\y# = a\y# + a\vy#*(1.0 - a\tu#) 
  Next
 
End Function

Function Render()
  For k.Kugel = Each Kugel
    Color 0,0,k\clr
    Oval Int(k\x#-k\r),Int(k\y#-k\r),2*k\r,2*k\r
  Next
 
  Color 0,255,0
  Text 10,10,"Energie: " + energie,0,0
 
End Function

Function CreateKugel.Kugel(x#,y#,vx#,vy#,rad%,r%,g%,b%)
  newkugel.Kugel = New Kugel
  newkugel\x# = x#
  newkugel\y# = y#
  newkugel\vx# = vx#
  newkugel\vy# = vy#
  newkugel\r% = rad%
  newkugel\clr% = $10000 * r + $100 * g + b
  Return newkugel
End Function