As with 'large_cave_depth', lava depth was previously a fixed y value and
therefore incompatible with the ability to shift terrain vertically.
Add 'lava_depth' mapgen parameter to mgflat, mgfractal, mgv5, mgv7.
Add to MapgenBasic for use by multiple mapgens.
Add to mgv5 and mgv7, enabled by default.
Similar to mgvalleys caverns but half the scale.
Parameters for upper y limit, distance caverns taper to full size, and
noise threshold (full cavern size).
As with mgvalleys caverns are generated first and classic caves are
disabled in any mapchunk containing a cavern, to avoid excessive
spreading volumes of liquids.
This also avoids floating blobs of liquid where a large classic cave
has overgenerated out into a neighbouring previously-generated mapchunk.
- Convert instances of numeric literal doubles to floats
- Move dswitchint to a local variable now that being a member is unnecessary
- Improve const correctness
- Indentation fixes
When tunnels entirely above ground were avoided, the
missing pseudorandom calls changed the allowed caves.
Now, above ground tunnels are not placed while
still running all previous pseudorandom calls.
