add collisions and sliding for player movement

1 files changed, 10 insertions, 0 deletions

diff --git a/common/coords.lua b/common/coords.lua
index 49c2bf2..420b287 100644
--- a/common/coords.lua
+++ b/common/coords.lua
@@ -75,6 +75,16 @@ function Hex.offset_in_chunk(self)
 	local cp,offs = self:chunk_and_offset()
 	return offs
 end
+function Hex.iter_neighbours(self,radius)
+	assert(radius > 0,"radius must be at least 1")
+	return coroutine.wrap(function()
+		for q = -radius,radius do
+			for r = math.max(-radius,-q-radius), math.min(radius,-q+radius) do
+				coroutine.yield(self+Hex:make(q,r))
+			end
+		end
+	end)
+end
 function Hex.__add(self,other) return Hex:make(self.q+other.q, self.r+other.r, self.s+other.s) end
 function Hex.__sub(self,other) return Hex:make(self.q-other.q, self.r-other.r, self.s-other.s) end
 function Hex.__tostring(self) return string.format("H(%.2f,%.2f)",self.q,self.r) end