local class = require"common.class"
local chunk = require"common.chunk"
local Chunk = require"common.chunk".Chunk
local CHUNK_SIZE = require"common.constants".CHUNK_SIZE

local ChunkC = class.extend(chunk.Chunk)
function ChunkC.make(cls,...)
	local self = chunk.Chunk.make(cls,...)
	self.imesh = cls.imesh_from_chunk_data(self)
	return self
end
local function tile_to_vattr(tile)
	-- for now tiles are always numbers
	-- so this just returns the input
	-- this function might move to drawing.lua
	-- once it does something less trivial
	assert(type(tile) == "number",
		"can't send non-numerical tile to gpu")
	return tile
end
function ChunkC.imesh_from_chunk_data(the_chunk)
	local mesh_data = {}
	for q=0,CHUNK_SIZE-1 do
		for r =0,CHUNK_SIZE-1 do
			local t = the_chunk:_atqr(q,r)
			table.insert(mesh_data,{tile_to_vattr(t)})
		end
	end

	local imesh = love.graphics.newMesh({
		{"tile_type","float",1}
	}, mesh_data, nil, "dynamic")

	return imesh
end

function ChunkC.set_at(self,hoffs,tile)
	Chunk.set_at(self,hoffs,tile)

	local idx = chunk.index(hoffs.q,hoffs.r)
	self.imesh:setVertexAttribute(idx, 1, tile_to_vattr(tile))
end

return {ChunkC=ChunkC}