Tile improved

Tonight I am very tired, but very happy because I think the project does what I had hoped from its beginning.
Today I have modified the classes responsible to render WMS layers. Now the variable used to request more precise images depends on two factor:

• The distance of the camera to the earth surface, and
• the longitude of the diagonal arc of the tile.

v = altitude / arclong

It seems that a proportion until 0.5 is good, then when the value is less than 0.5 it is time to request more little tiles