Add chunk wrapping

zchunk.lua

@@ -4,6 +4,7 @@ local zprite = require("zprite.zprite")
 ---@field private _chunks {integer: {z: zprite, x: integer, y: integer}}
 ---@field private _chunk_size integer
 ---@field private _chunk_height integer
+---@field private _chunk_wrap integer
 ---@field private _texture love.Image
 ---@field private _height_scale number
 local zchunk = {}
@@ -12,7 +13,8 @@ zchunk.__index = zchunk
 ---@param texture love.Image
 ---@param chunk_size integer?
 ---@param chunk_height integer?
-function zchunk.new(texture, chunk_size, chunk_height)
+---@param chunk_wrap integer?
+function zchunk.new(texture, chunk_size, chunk_height, chunk_wrap)
 	chunk_size = chunk_size or 16
 	chunk_height = chunk_height or 32
 	if chunk_size < 1 then
@@ -21,6 +23,9 @@ function zchunk.new(texture, chunk_size, chunk_height)
 	if chunk_height < 1 then
 		error("chunk height must be at least 1")
 	end
+	if chunk_wrap and chunk_wrap < 1 then
+		error("chunk wrap must be at least 1")
+	end
 	if not texture then
 		error("must have a texture")
 	end
@@ -30,6 +35,7 @@ function zchunk.new(texture, chunk_size, chunk_height)
 	obj._chunks = {}
 	obj._chunk_size = chunk_size
 	obj._chunk_height = chunk_height
+	obj._chunk_wrap = chunk_wrap
 
 	obj._texture = texture
 
@@ -42,7 +48,14 @@ end
 ---@param y integer
 ---@return integer
 function zchunk:_chunk_index(x, y)
-	return math.floor(x / self._chunk_size) + math.floor(y / self._chunk_size) * 1e7
+	local cx = math.floor(x / self._chunk_size)
+	local cy = math.floor(y / self._chunk_size)
+	if self._chunk_wrap then
+		cx = cx % self._chunk_wrap
+		cy = cy % self._chunk_wrap
+	end
+
+	return cx + cy * 1e7
 end
 
 ---@param x integer?
@@ -52,10 +65,7 @@ function zchunk:remove(x, y)
 		self._chunks = {}
 	else
 		local index = self:_chunk_index(x, y)
-		if not self._chunks[index] then
-			return
-		end
-		self._chunks[index] = {}
+		self._chunks[index] = nil
 	end
 end
 
@@ -80,19 +90,19 @@ end
 ---@param y number
 ---@param quad love.Quad
 ---@param layer_count integer
----@param color_map fun(integer): number, number, number, number?
+---@param color_map fun(layer: integer): number, number, number
 ---@param base_layer integer?
 function zchunk:put(x, y, quad, layer_count, color_map, base_layer)
 	local index = self:_chunk_index(x, y)
 	if not self._chunks[index] then
 		self._chunks[index] = {
 			z = zprite.new(self._texture, self._chunk_size * self._chunk_size * self._chunk_height),
-			x = math.floor(x / self._chunk_size),
-			y = math.floor(y / self._chunk_size),
 		}
 		self._chunks[index].z._height_scale = self._height_scale
 	end
 	self._chunks[index].z:put(x, y, quad, layer_count, color_map, base_layer)
+	self._chunks[index].x = math.floor(x / self._chunk_size)
+	self._chunks[index].y = math.floor(y / self._chunk_size)
 end
 
 local transform = love.math.newTransform()