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/ Power Bytes: Money & Finance / PowerBytes Money and Finance CD-ROM 01 / PowerBytes Money and Finance CD-ROM 01.iso / Demos / TrueBASIC Demo / User's Guide / Bounce next >
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Text File  |  1985-10-19  |  641 b   |  22 lines  |  [TEXT/TRUE]
  1. ! A bouncing ball.
  2.  
  3. SET WINDOW 0, 30, 0, 20
  4.  
  5. LET delta = +1                         ! +1 is up, -1 is down
  6. LET x = 15                             ! Start in center
  7. LET y = 10
  8.  
  9. BOX CIRCLE x, x+1, y, y+1              ! Show first ball
  10. FLOOD x+.5, y+.5                       ! Fill in circle
  11. BOX KEEP x, x+1, y, y+1 in ball$       ! Remember that image
  12.  
  13. DO
  14.     BOX CLEAR x, x+2, y, y+2           ! Erase old ball
  15.     LET y = y + delta                  ! Continue on course
  16.     IF y < 1 OR y > 19 then LET delta = -delta   
  17.  
  18.     BOX SHOW ball$ at x,y               ! Draw new ball
  19.     PAUSE .05                           ! Not too fast
  20. LOOP
  21. END
  22.