clientside chunk unloading when not near. also refactor coordinate things slightly

1 files changed, 15 insertions, 0 deletions

diff --git a/common/coords.lua b/common/coords.lua
index 111429a..49c2bf2 100644
--- a/common/coords.lua
+++ b/common/coords.lua
@@ -136,6 +136,21 @@ function ChunkPos.extents(self)
 	local brq,brr = (self.u+1)*CHUNK_SIZE -1, (self.v+1)*CHUNK_SIZE -1
 	return Hex:make(tlq,tlr), Hex:make(brq,brr)
 end
+function ChunkPos.neighborhood(self)
+	-- return all chunkposes within the 3x3 square centered on self, including self
+	local out = {}
+	for du=-1,1 do
+		for dv = -1,1 do
+			table.insert(out,ChunkPos:make(du,dv) + self)
+		end
+	end
+	return out
+end
+function ChunkPos.orth_dist(self,other)
+	local du = math.abs(self.u-other.u)
+	local dv = math.abs(self.v-other.v)
+	return math.max(du,dv)
+end
 function ChunkPos.filename(self)
 	-- filename of chunk with that cp
 	return "world/c_"..self.u.."_"..self.v..".dat"