Changes

The following bit of code is a skeleton which you can use as an aid to help you write your own parserfor XB PointStream.

/** XBPS will create an instance of your parser and pass in an object with three named properties:

start - must occur exactly once. Has one argumentWhen you call this function, the pass in a reference to your parser itself end - must occur exactly once. Has When you call this function, pass in a reference to your parser parse - may occur one or many times. When you call this function, pass in a reference to your parser as the first argument, and an object as the parser itselfsecond argument.

Everytime your parser calls the parse function, it This second object must send in an object withhave variables referencing typed single-dimensional arrays which contain named arraysthe parsed values. In the following For example, vertexArray is a if vertsArray and colsArray were Float32Array which containarrays, you would call the vertices which have already been read and parsed.parse function like this:

attributes["ps_Vertex"] = vertexArrayvertsArray; attributes["ps_Color"] = colorsArraycolsArray; parse(thisParser, attributes);  PointStream will create buffers using these values and start rendering them using the built-in shaders. Notice the variable names have been qualified with "ps_". If you are using the XB PointStream built-in shaders, you will need to use these exact variable names.

parse These are the only two variables the built- may occur one or many timesin shaders read. Has two argumentsIf your parser reads in vertex normal data, the parser itself and a Your parser is responsible for calling these functions at the appropriate timesyou will need to write your own shaders to handle lighting.

this.__defineGetter__("version", function(){ return /*!!*/; });

this.__defineGetter__("numParsedPoints", function(){ return /*!!*/; });

this.__defineGetter__("numTotalPoints", function(){ return /*!!*/; });

this.__defineGetter__("progress", function(){ return /*!!*/; });

this.__defineGetter__("fileSize", function(){ return /*!!*/;}); /*Path = path to the resource */ this.load = function(path){/*!!*/}; } return Your_Parser_Name;}());</pre> == Putting Everything Together == === Sample Parser ===Here is a very simple parser which only reads in vertex data from a file.<pre>/*The following is a very simple parser written only to be used as an example of how a user could write a parser for XB PointStream.*/var FOO_Parser = (function() {  function FOO_Parser(config) {

var start = config.start || function(){}; var parse = config.parse || function(){}; var end = config.end || function(){}; var fileSizeInBytes = 0; var numParsedPoints = 0; var numTotalPoints = 0; var progress = 0; // keep track if onprogress event handler was called to // handle Chrome/WebKit vs. Minefield differences. // Minefield will call onprogress zero or many times // Chrome/WebKit will call onprogress one or many times var onProgressCalled = false; var AJAX = null; /* Returns the version of this parser. */ this.__defineGetter__("version", function(){return 0.1;}); /*Get the number of parsed points so far. */ this.__defineGetter__("numParsedPoints", function(){return numParsedPoints;}); @param path Path /* Get the total number of points in the point cloud. */ this.__defineGetter__("numTotalPoints", function(){ return numTotalPoints;}); /* Get the progress of downloading the point cloud (zero to one or -1 if unknown) */ this.__defineGetter__("progress", function(){ return progress;}); /* Returns the file size of the resourcein bytes. */ this.__defineGetter__("fileSize", function(){return fileSizeInBytes;});  /**/

  AJAX = new XMLHttpRequest(); AJAX.parser = this;  /*occurs exactly once, when the resource begins to be downloaded */ AJAX.onloadstart = function(evt){ start(AJAX.parser); }; /*occurs exactly once, when the file is done being downloaded */ AJAX.onload = function(evt){ var ascData = AJAX.responseText; var chunk = null;  // if the onprogress event didn't get called--we simply got // the file in one go, we can parse from start to finish. if(onProgressCalled === false){ chunk = ascData; } // otherwise the onprogress event was called at least once, // that means we need to get the data from a specific point to the end. else if(ascData.length - AJAX.lastNewLineIndex > 1){ chunk = ascData.substring(AJAX.lastNewLineIndex, ascData.length); }  AJAX.parseChunk(chunk);  numTotalPoints = numParsedPoints; progress = 1; end(AJAX.parser); }  AJAX.parseChunk = function(chunk){ // this occurs over network connections, but not locally. if(chunk !!== ""){ // trim leading and trailing spaces chunk = chunk.replace(/\s+$/,""); chunk = chunk.replace(/^\s+/,""); // split on white space chunk = chunk.split(/\s+/); var numVerts = chunk.length/3; numParsedPoints += numVerts; var verts = new Float32Array(numVerts * 3);  for(var i = 0, j = 0, len = chunk.length; i < len; i += 3, j += 3){ verts[j] = parseFloat(chunk[i]); verts[j+1] = parseFloat(chunk[i+1]); verts[j+2] = parseFloat(chunk[i+2]); } // XB PointStream expects an object with named/value pairs // which contain the attribute arrays. These must match attribute // names found in the shader parse(AJAX.parser, {"ps_Vertex":verts}); } }; /*On Minefield, this will occur zero or many times On Chrome/WebKit this will occur one or many times */ AJAX.onprogress = function(evt){ if(evt.lengthComputable){ fileSizeInBytes = evt.total; progress = evt.loaded/evt.total; }  onProgressCalled = true;  // if we have something to actually parse if(AJAX.responseText){ var ascData = AJAX.responseText;  // likely stopped getting data in the middle of a line in the file: // 1.079 1.296 9.360 0 0 0 4.307 1.181 5.208\n // 3.163 2.225 6.139 0 0 0 0.6<-- stopped here // So find the last known newline. Everything from the last // request to this last newline can be placed in a buffer. var lastNewLineIndex = ascData.lastIndexOf("\n"); AJAX.lastNewLineIndex = lastNewLineIndex; // if the status just changed and we finished downloading the // file, grab everyting until the end. If there is only a bunch // of whitespace, make a note of that and don't bother parsing. if(AJAX.readyState === 4){ var chunk = ascData.substring(AJAX.startOfNextChunk, ascData.length); AJAX.parseChunk(chunk); } // if we still have more data to go else{ // Start of the next chunk starts after the newline. var chunk = ascData.substring(AJAX.startOfNextChunk, lastNewLineIndex + 1); AJAX.startOfNextChunk = lastNewLineIndex + 1; AJAX.parseChunk(chunk); } } }; AJAX.open("GET", path, true); AJAX.send(null);

return Your_Parser_NameFOO_Parser;