* fix integer overflow in mapgen
Some calculations involving the magic seed had overflow because the result of an intermediate arithmetic step could not fit in an s32. By making the magic seed unsigned, the other operand in the equation will be cast to unsigned, and possibly other operands or intermediate operands. This will result in unexpected behavior if an operand is negative, which is technically possible, but logically should not happen.
* comment noise2d bitshift
While working through the code I was momentarily concerned that the right bitshift in noise2d could fill ones in some cases. It turns out that with signed integers, this is indeed true, but this one is shifting an unsigned integer, so the behavior is as expected. I put a comment here to clarify this, in case someone else wonders the same thing down the line.
* noise2d and noise3d unittests
I have added 3 tests each for noise2d and noise3d, testing all zero inputs, a very large seed (case which caused UB in the old implementation) and some fun primes I picked for no particular reason. This should be sufficient to demonstrate that the behavior of the new implementation has not changed. I used uniform initialization because it is a good feature of C++11. Please do not explode.
* uncomment the noise2d bitshift
This reverts commit 583b77ee9f1ad6bb77340ebb5ba51eb9a88ff51c. It's a
well-defined language semantic; it doesn't need to be commented.
* code cleanliness
fixes:
* Switching between games does not immediately hide creative mode / damage buttons if so specified
* World creation menu has a game selection list even though the menu already provides a gamebar
* Showing gameid in world list is unnecessary
* Choice of mapgen parameters in menu persists between games (and was half-broken)
This fixes an out-of-bounds index access when the node resolver was already applied to the schematic (i.e. biome decoration).
Also improves the handling of the two cases: prior node resolving (m_nodenames), and after node resolving (manual lookup)
All terrain generation now occurs in one loop, instead of rivers being
carved afterwards in a separate loop.
Fixes the removal of nodes added by mods in 'register on generated'.
Avoids other problems and reduces the chance of future bugs.
Mapchunk generation time is reduced.
Also fixes a code mistake which resulted in river channel generation
being disabled at floatland altitudes even when floatlands were disabled.
Run unused functions reported by cppcheck
This change removes a few (but not all) unused functions.
Some unused helper functions were not removed due to their complexity and potential of future use.
This commit clarifies the maximal length of the serialized strings.
It will avoid accidental use of serializeString() when a larger string can be expected.
Removes unused Wide String serialization functions
Games often and increasingly do not use this mapgen alias, as it
is only required for Mapgen V6. Such games were triggering the
recently added error message.
Even if this mapgen alias was defined, dirt nodes placed under a
wide trunk were inconsistent with biomes that do not use dirt
surface nodes.
Place trunk nodes below a wide trunk instead of 'mapgen_dirt'.
On sloping ground, the trunk then extends down to the surface,
instead of the surface rising up to meet the trunk. This looks
more natural and does not alter the terrain.
Floatland structure is vertically-compressed 3D noise.
Uses a lacunarity of 1.618 (the golden ratio) for high quality
noise.
Floatlands appear between user-settable Y limits, with smooth
tapering at each limit.
Simple user-settable density adjustment.
Shadow propagation is disabled in and just below floatlands, no
shadows are cast on the world surface.
Can be reconfigured to create a solid upper world layer between
the Y limits, lakes/seas can be optionally added to this.
