minecraft.js/lib/region.js

Minecraft data serialization/deserialization and networking

var constants = require(__dirname + '/constants.js');

/** @constructor */
var Region = module.exports = function() {
    this.chunks = [];
    for(var i = 0; i < constants.REGION_SIZE; i++) {
        this.chunks[i] = [];
    }
};

Region.prototype.getChunk = function(x, z) {        
    return this.chunks[x & constants.REGION_SIZE - 1][z & constants.REGION_SIZE - 1];
};

Region.prototype.setChunk = function(x, z, chunk) {
    if(x >= 0 && x < constants.REGION_SIZE && z >= 0 && z < constants.REGION_SIZE) {
        this.chunks[x][z] = chunk;
        return this;
    } else {
        throw new Error('Chunk coordinates out of bounds');
    }
};

Region.prototype.toText = function(callback) {
	var locations = [],
		timestamps = [],
		data = [],
		completed = 0,
		offset = 0,
		output = '';
			
	//for each chunk, build deflated binary data, add to chunk data
	var processChunks = function(region) {
		for(var i = 0; i < constants.REGION_SIZE; i++) {
			for(var j = 0; j < constants.REGION_SIZE; j++) {
				if(typeof region.chunks[i][j] != 'undefined') {
					var chunk = region.chunks[i][j];
					var id = i * constants.REGION_SIZE + j;
					
					data[id] = RawDeflate.deflate(chunk.toTag().toText()); 
					var sectorCount = Math.ceil((data[id].length + 5) / 4096);
						
					//add chunk info to header
					locations[id] = ((offset / 4096) << 24) + sectorCount;
					timestamps[id] = 0; //TODO: figure this out
					
					//create chunk metadata
					data[id].length; //size of chunk (in bytes) 
					 //Zlib compression (we just use DEFLATE)
					
					//add 4 bytes to the end for Zlib
					var footer = '\0\0\0\0';
					
					offset += sectorCount * 4096;
					completed++;
				} else completed++;
			}
		}
	};
	setTimeout(processChunks, 0, this);
	
	var waitForEnd = function() {
		if(completed >= constants.REGION_SIZE * constants.REGION_SIZE - 1) {
			callback(output);
		} else setTimeout(waitForEnd, 40);
	};
	waitForEnd();
};