Port wood gathering and fix 26.3 swing animation

mosfet/world.py

@@ -81,9 +81,14 @@ class World:
                 return result
 
     def find_trees(self, center, distance):
-        found_trees = []
-        for log in self.find_blocks_3d(center, blocks.LOG_IDS, distance, 15):
-            # crawl to the bottom log
+        found_trees = set()
+        # 26.3 block-state caches keep an index of tree logs. Searching a
+        # three-dimensional radius voxel-by-voxel is prohibitively expensive
+        # and can walk through unloaded space, so use loaded indexed states.
+        for candidate in self.find_blocks_indexed(
+                center, blocks.LOG_IDS, distance):
+            # Crawl to the bottom log of this trunk.
+            log = candidate
             while self.block_at(*utils.padd(log, path.BLOCK_BELOW)) in blocks.LOG_IDS:
                 log = utils.padd(log, path.BLOCK_BELOW)
             base = log
@@ -91,27 +96,25 @@ class World:
             if base in found_trees:
                 continue
 
-            # make sure we are on the ground
-            if self.block_at(*utils.padd(base, path.BLOCK_BELOW)) in blocks.NON_SOLID_IDS:
+            # Only classify trees when their supporting block is known.
+            support = self.block_at(*utils.padd(base, path.BLOCK_BELOW))
+            if support is None or support in blocks.NON_SOLID_IDS:
                 continue
 
-            # crawl to the top log to count and check leaves
+            # Crawl to the top log to count trunk blocks and check for leaves.
             log_count = 1
             good_leaves = False
             while self.block_at(*utils.padd(log, path.BLOCK_ABOVE)) in blocks.LOG_IDS:
                 log = utils.padd(log, path.BLOCK_ABOVE)
                 log_count += 1
-
                 for offset in path.CHECK_DIRECTIONS:
                     if self.block_at(*utils.padd(log, offset)) in blocks.LEAF_IDS:
                         good_leaves = True
 
-            # make sure it's a good tree
             if not good_leaves or log_count < 3:
                 continue
 
-            found_trees.append(base)
-
+            found_trees.add(base)
             yield base
 
     def find_tree_openings(self, tree):