DRAG BUFFER USAGE

The drag buffer stores areas of the map image which you have dragged out of the window.  These areas remain available so that they may later be dragged back into the window.  They will remain available until one of two things happen: one, you drag the map far enough that they are pushed beyond the edge of the buffer; or, two, you do an operation that totally makes the old image obsolete, such as zooming or loading a map from another series.

Your choice will affect how this buffer is used, and what you will see while the map is being drawn.  Your choices are:

    Preload drag buffer.

Generally it is nice to have the buffer preloaded while the map is being drawn.  This choice ensures that any areas of the loaded maps which lie just beyond the edges of the window will always be available when you drag the map.  Because the actual drawing will be done in the buffer before being copied to the window, you will not see the drawing in progress.

You may, at times, prefer to see the drawing in progress.  This choice will allow you to do that.  When zooming, or otherwise redrawing the map, this allows you to see each item as soon as it is drawn, rather than waiting until the drawing is complete.  (It may also be more entertaining than staring at the wait cursor.)  However, because the actual drawing will be done in the window before being copied to the drag buffer, surrounding areas of the buffer will not be preloaded.  The only other areas available in the drag buffer will be those which you have previously dragged beyond the edge of the window.

This choice allows you to both preload the drag buffer and watch the drawing in progress -- sort of.  With this choice the drawing is done in the buffer and the window is updated as each theme is completed for each map.  So you will not see each item on the map quite as soon as it is drawn, but soon after.  And because the window is updated once per theme for every map, the drawing will take a bit longer than usual.

Copyright © 2002 by Dapper Mapper