public boolean chunkExists(int cx, int cy) {
return cx >= 0
&& cy >= 0
&& cx < sizeChunks
&& cy < sizeChunks
&& chunks.keys.contains(Chunk.getChunkIndex(cx, cy));
}
public Chunk getChunk(int cx, int cy) {
return chunks.get(Chunk.getChunkIndex(cx, cy));
}