What is the 'right' way to move an image blit'd onto another?

Mar 4, 2014 at 2:26 PM
I have a large bitmap of a map that I am dropping objects onto. When the user drops the object, I pull the small bitmap (icon) associated with the object and blit it onto the map. Works fine.

Later if the user wants to move the icon, I detect that the user has clicked in the icons's Rect and as the mouse moves I want the icon to go with it until the user releases the mouse.

What is the 'right' way to make the icon move across the map? My instinct is to keep an undisturbed copy of the map in memory and then blit icon-sized patches from it over the old icon before blit'ing the icon again in the new location. I know that technique is straight out of the 80's... that is why I am asking if WriteableBitmapEx has a more sophisticated plan for this.