Operations of the Tilda (~) key

[avivlewis10]

The Tilda key should paint the part of the map/picture in green.

1. after one press on the Tilda key (and making the screen green), second press will cancel the green screen.
2. after zoom in into the green screen and pressing on the Tilda key again (only if all the screen is in green after the zoom in), the current screen won't be painted anymore.
3. after zoom out when only part of the screen is painted and pressing again on the Tilda key, the hole current screen will be green.