#include "fbgfx.bi"

const ScreenWid=640,ScreenHei=480

screenres ScreenWid,ScreenHei,8  'setup 640x480x8bpp (256 colors)
width ScreenWid\8,ScreenHei\16   'set font size to 8x16

'iDirX is how many pixels it moves per frame (initially 1 (to the right))
'since we're going from -10 to 10... that number must be a divisor of 10
'so must be one of 1,2,5 or 10 (this simplify the check)
dim as integer iOffsetX,iDirX=1
dim as integer iPosX,iPosY
dim as string sSentence = "Hello World"

'calculate center position for sentence
iPosX = (ScreenWid-len(sSentence)*8)\2 'horizontal
iPosY = (ScreenHei-16)\2      'vertical

do

  screenlock 'block screen from update
    cls 'clears whole screen (could fill just an area)
    'draw centered text over right position (in yellow)
    Draw String ( iPosX+iOffsetX , iPosY ) , sSentence , 14

    iOffsetX += iDirX 'change position depending on direction (left/right)
    if iOffsetX = -10 orelse iOffsetX = 10 then
      iDirX = -iDirX 'if it hit side positions invert direction
    end if
  screenunlock 'allow display of the screen
  sleep 30 'waits 30ms... making roughly 30fps

  'draw frames until ESC is pressed
loop until multikey(fb.SC_ESCAPE)