Moving over background larger than screen

[SMcNeill]

Since you guys are all having fun with this, here's a Steve Simple version of screen scrolling at work.   Just use the mouse and watch what happens!

Code: (Select All)

Screen _NewImage(800, 600, 32) 'the screen that the user is going to see

Background = _NewImage(800 * 3, 600 * 3, 32) 'my background which is 3 times larger than my screen

_Dest Background

_PrintMode _KeepBackground



'Create a background which we can scroll and view via the mouse

For x = 0 To 2

    For y = 0 To 2

        Line (x * 800, y * 600)-Step(800, 600), _RGB(x * 127.5, y * 127.5, Rnd * 256), BF 'draw each quadrent a different color

        For i = 0 To 37

            text$ = "QUADRENT" + Str$(y * 3 + x + 1) + ": LINE #" + Str$(i)

            _PrintString (x * 800, y * 600 + i * _FontHeight), text$

        Next

    Next

Next



StartX = 800: StartY = 600

_MouseMove 400, 300 'center the mouse before we start scrolling like crazy

_Delay .2 'give the mouse time to move to the proper position for starting

Do

    While _MouseInput: Wend

    'If the mouse is near an edge, then change the starting points to reflect the scrolling

    If _MouseX < 20 Then StartX = StartX - (20 - _MouseX): If StartX < 0 Then StartX = 0

    If _MouseX > 779 Then StartX = StartX + (_MouseX - 779): If StartX > 1600 Then StartX = 1600

    If _MouseY < 20 Then StartY = StartY - (20 - _MouseY): If StartY < 0 Then StartY = 0

    If _MouseY > 579 Then StartY = StartY + (_MouseY - 579): If StartY > 1200 Then StartY = 1200

    _PutImage (0, 0)-Step(800, 600), Background, 0, (StartX, StartY)-Step(800, 600)

    _Display

    _Limit 60

Loop Until _MouseButton(1) Or _MouseButton(2) 'press a mouse button to end

System

Note: The closer your mouse gets to the edge, the faster the scrolling. Advance your pointer slowly towards the edge and watch as the scroll speed increases and decreases as you approach the edge more.