'**********************************************
' Description : Explosions - VGA mode 13 special effect
' Written by : Andrew L. Ayers
' Date : 10/22/96
'
' The name says it all!
'
' You may use this routine in any manner you like, as long
' as you give credit in an appropriate manner. Have phun!
'
Screen 13

Dim As Short x(50), y(50), xv(50), yv(50), ox(50), oy(50)
Dim As Short dir1,vel,tx,ty,c,done

Do
  Cls
  For t As Integer = 0 To 50
   x(t) = 0
   y(t) = 0
   dir1 = Rnd * 6.28: vel = Int(Rnd * 5) + 1
   xv(t) = Sin(dir1) * vel
   yv(t) = Cos(dir1) * vel
  Next
  '
  tx = Int(Rnd * 320)
  ty = Int(Rnd * 200)
  c = 31: done = 0

  Locate 1, 6: Print "Explosions by Andrew L. Ayers"
  Locate 23, 8: Print "Press any key to exit demo"

  Do
   For t As Integer = 0 To 50
    Line (ox(t) + tx, oy(t) + ty)-(x(t) + tx, y(t) + ty), 0
    ox(t) = x(t): oy(t) = y(t)

    x(t) = x(t) + xv(t)
    y(t) = y(t) + yv(t)

    Line -(x(t) + tx, y(t) + ty), Int(Rnd*15)
   Next
   c = c - 1: If c < 16 Then done = 1
   If Inkey <> "" Then done = 2
   Sleep 25
  Loop Until done
Loop Until done = 2