{ return schunk_read[12*(cy/chunks_per_schunk) + cx/chunks_per_schunk]; }
{ return schunk_read[12*(cy/c_chunks_per_schunk) + cx/c_chunks_per_schunk]; }
	bool is_chunk_read(int cx, int cy)		{ return schunk_read[12*(cy/chunks_per_schunk) +						cx/chunks_per_schunk]; }