Moving over background larger than screen

[bplus]

https://qb64phoenix.com/forum/showthread...4#pid30124
(It's reply #6 if you are dropped to bottom of page on links like I am in this forum.)

If @TempodiBasic can't figure it out then maybe other people could use help too...

Basic setup for playing a game over a very large background. Use arrow keys to move over background in that direction. If you stop, you have gone to edge of background.

Code: (Select All)

_Title "Image bigger than screen" ' b+ 2024-12-02
Randomize Timer
Screen _NewImage(800, 600, 32)
_ScreenMove 100, 20

Dim bg&
bgw = 1600 ' double width and height for demo
bgh = 1200
bg& = _NewImage(bgw, bgh, 32)
_Dest bg&
For i = 1 To 80
    Line (Rnd * bgw, Rnd * bgh)-Step(Rnd * 100 + 50, Rnd * 75 + 25), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), BF
Next
_Dest 0
d = 0: e = 0
While _KeyDown(27) = 0
    Cls
    k = _KeyHit
    If k = 19200 Then d = -1: e = 0 ' left
    If k = 19712 Then d = 1: e = 0 ' right
    If k = 18432 Then e = -1: d = 0 ' up
    If k = 20480 Then e = 1: d = 0 'down

    top = top + e
    If top < 0 Then top = 0
    If top + _Height > bgh Then top = bgh - _Height

    le = le + d
    If le < 0 Then le = 0
    If le + _Width > bgw Then le = bgw - _Width

    _PutImage (0, 0)-(_Width, _Height), bg&, 0, (le, top)-(le + _Width, top + _Height)

    _Display
    _Limit 120
Wend

Of course you can do this step by step too with the arrow keys.

Code: (Select All)

_Title "Step through Image bigger than screen" ' b+ 2024-12-02
Randomize Timer
Screen _NewImage(800, 600, 32)
_ScreenMove 100, 20

Dim bg&
bgw = 1600 ' double area for demo
bgh = 1200
bg& = _NewImage(bgw, bgh, 32)
_Dest bg&
For i = 1 To 80
    Line (Rnd * bgw, Rnd * bgh)-Step(Rnd * 100 + 50, Rnd * 75 + 25), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), BF
Next
_Dest 0
stepper = 5  ' <<< set step size here!!!
While _KeyDown(27) = 0
    Cls
    k = _KeyHit
    If k = 19200 Then ' left
        If le - stepper >= 0 Then le = le - stepper
    End If
    If k = 19712 Then ' right
        If le + stepper <= bgw - _Width - 1 Then le = le + stepper
    End If
    If k = 18432 Then ' up
        If top - stepper >= 0 Then top = top - stepper
    End If
    If k = 20480 Then 'down
        If top + stepper <= bgh - _Height - 1 Then top = top + stepper
    End If

    _PutImage (0, 0)-(_Width, _Height), bg&, 0, (le, top)-(le + _Width, top + _Height)

    _Display
    _Limit 120
Wend