Passed down tile for carve to avoid lock hits when grabbing the tile …

[qf200011]

When doing the carve step of the cave layer, the tile used to be grabbed from the dimension

final int terrainHeight = dimension.getIntHeightAt(x, y);

This is problematic because within getIntHeightAt, we would get the tile by calling getTile

public int getIntHeightAt(int x, int y, int defaultHeight) { Tile tile = getTile(x >> TILE_SIZE_BITS, y >> TILE_SIZE_BITS); if (tile != null) { return tile.getIntHeight(x & TILE_SIZE_MASK, y & TILE_SIZE_MASK); } else { return defaultHeight; } }

getTile will return the tile properly but it first has to get a lock before doing so.

public Tile getTile(final int x, final int y) { readLock.lock(); try { return tiles.get(new Point(x, y)); } finally { readLock.unlock(); } }

Because getting a lock and releasing it is relativly intensive when being done frequently, a large amount CPU time was spent just getting and releasing the lock.

After the changes which passes the tile down a few steps, the carve step of cave was reduced in cpu time by 57%.