scroll

void scroll(int  x,  int  y,  int  w,  int  h,  int  dx,  int  dy,
       ScrollDrawAreaCallback drawArea =  null,  void *  data =  null)

nothrow @nogc

Scrolls a rectangle by a given amount.

The uncovered areas will need to be redrawn. A callback can be provided to handle drawing these areas.

`x`	X coordinate of rectangle
`y`	Y coordinate of rectangle
`w`	Width of rectangle
`h`	Height of rectangle
`dx`	Horizontal scroll amount (positive = right)
`dy`	Vertical scroll amount (positive = down)
`drawArea`	Optional callback to draw uncovered areas
`data`	User data passed to callback