Resize window is broken

[WizzerWorks]

When the window is re-sized, the world coordinate mapping is sometimes mapped to the wrong extent. This is more noticeable when zoomed into the viewport, where the world coordinates don't map directly to the window's device coordinates.

[WizzerWorks]

Simplified setting the world coordinate extent so that the existing extent will be mapped to the new device coordinates. This may look strange when the user is rapidly changing the size of the window; however, the arithmetic is accurate.