add falling_block entity

res/content/base/scripts/components/falling_block.lua

@@ -0,0 +1,31 @@
+local tsf = entity.transform
+local body = entity.rigidbody
+local rig = entity.modeltree
+
+ARGS = ARGS or {}
+local blockid = ARGS.block
+if SAVED_DATA.block then
+    blockid = SAVED_DATA.block
+else
+    SAVED_DATA.block = blockid
+end
+
+do -- setup visuals
+    local textures = block.get_textures(block.index(blockid))
+    for i,t in ipairs(textures) do
+        rig:set_texture("$"..tostring(i-1), "blocks:"..textures[i])
+    end
+end
+
+function on_grounded()
+    local pos = tsf:get_pos()
+    local ix = math.floor(pos[1])
+    local iy = math.floor(pos[2])
+    local iz = math.floor(pos[3])
+    if block.is_replaceable_at(ix, iy, iz) then
+        block.set(ix, iy, iz, block.index(blockid))
+    else
+        entities.spawn("base:drop", pos, {item={id=item.index(blockid..".item"), count=1}}) 
+    end
+    entity:despawn()
+end