blockdata.js

'use strict';

module.exports = function(game, opts) {
  return new BlockData(game, opts);
};

function BlockData(game, opts) {
  this.game = game;

  this.enable();
}

BlockData.prototype.enable = function() {
  var self = this;

  this.game.on('setBlock', this.onSetBlock = function(target) {
    // clear blockdata when blocks change
    self.clear.apply(self, target);
  });
};

BlockData.prototype.disable = function() {
  this.game.removeListener('setBlock', this.onSetBlock);
};


// API

// Get the blockdataMap for the chunk at given world coordinates
// Returns undefined if the chunk doesn't exist
// Initializes blockdataMap to {} if it doesn't exist (but the chunk does), _unless_ noCreate true
BlockData.prototype.getForChunk = function(x, y, z, noCreate) {
  var chunkIndex = this.game.voxels.chunkAtCoordinates(x, y, z).join('|');
  var chunk = this.game.voxels.chunks[chunkIndex];

  if (!chunk)
    return undefined;
  
  if (chunk.blockdata === undefined && !noCreate)
    chunk.blockdata = {};

  return chunk.blockdata;
};

BlockData.prototype.coordsToKey = function(x, y, z) {
  // TODO: should we translate global world coords to local chunk coords?
  return [x, y, z].join(',');
};

BlockData.prototype.get = function(x, y, z) {
  var blockdataMap = this.getForChunk(x, y, z);
  if (blockdataMap === undefined) return undefined;

  return blockdataMap[this.coordsToKey(x, y, z)];
};

BlockData.prototype.set = function(x, y, z, data) {
  var blockdataMap = this.getForChunk(x, y, z);
  if (blockdataMap === undefined) return undefined;

  blockdataMap[this.coordsToKey(x, y, z)] = data;
};

BlockData.prototype.clear = function(x, y, z) {
  var blockdataMap = this.getForChunk(x, y, z, true); // don't create for chunk if doesn't exist (read-only)
  if (blockdataMap === undefined) return undefined;

  delete blockdataMap[this.coordsToKey(x, y,z)];
};