== surface(area) ==
This is the constructor. It recieves the area the terrain references.
== setTerrain(terrain) ==
This method defines the main terrain to apply or change within the area.
== addTerrainLayer(terrain, percent) ==
This method adds a new terrain layer which borders the area. For example, going from shallow to deep water.
== replaceTerrain(old, new) ==
This method is used when you want a certain terrain type to be replaced with another in the case of overlapping areas.
== setForestType(type, percent) ==
This method is used to set a forest type and a percentage of how much of the land it takes up.
== setElevation(min, max) ==
This method defines the variable height of the area.
== setDepth(min, max) ==
This method defines the variable depth of the water area.
== modifyElevation(int, blendRadius) ==
This method raises/lowers the elevation of each tile by the specified int.
== modifyDepth(int, blendRadius) ==
This method raises/lowers the depth of each tile by the specified int.
== clearDepth() ==
This method clears depth of area.
== clearElevation() ==
This method clears elevation of area.