Perlin noise with Javascript

In Three.js a version of the Perling noise algorithm is used. They called it improved Noise. The noise-function is used in the terrain landscaps.

The Math.random()-Funktion produces other results, that we can't use in dynamic computer graphics.

In our simple example we assume a quite small and simple landscape.
For every point in the landscape we have to calcualte a third value the height.

It starts by gennerating a random number.
var z = Math.random(100);

The noise-function is called with 3 parameters,
var perlin = new ImprovedNoise();
perlin.noise(x,y,z);




69;70;72;73;75;76;77;78;79;80;
69;70;72;73;75;76;77;78;79;80;
69;70;72;73;75;76;78;79;79;80;
69;70;72;73;76;77;78;79;80;80;
69;70;73;74;75;77;78;79;80;80;
69;71;72;74;75;76;77;78;79;80;
68;71;72;73;75;76;77;78;79;79;
68;69;72;73;74;76;77;77;78;77;
68;69;70;73;74;74;75;76;77;77;
68;69;70;71;72;73;75;74;76;76;




   // http://mrl.nyu.edu/~perlin/noise/  
   var ImprovedNoise = function () {  
     var p = [151,160,137,91,90,15,131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,  
       23,190,6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,88,237,149,56,87,  
       174,20,125,136,171,168,68,175,74,165,71,134,139,48,27,166,77,146,158,231,83,111,229,122,60,211,  
       133,230,220,105,92,41,55,46,245,40,244,102,143,54,65,25,63,161,1,216,80,73,209,76,132,187,208,  
       89,18,169,200,196,135,130,116,188,159,86,164,100,109,198,173,186,3,64,52,217,226,250,124,123,5,  
       202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,223,183,170,213,119,  
       248,152,2,44,154,163,70,221,153,101,155,167,43,172,9,129,22,39,253,19,98,108,110,79,113,224,232,  
       178,185,112,104,218,246,97,228,251,34,242,193,238,210,144,12,191,179,162,241,81,51,145,235,249,  
       14,239,107,49,192,214,31,181,199,106,157,184,84,204,176,115,121,50,45,127,4,150,254,138,236,205,  
       93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180];  
     for (var i=0; i < 256 ; i++) {  
       p[256+i] = p[i];  
     }  
     function fade(t) {  
       return t * t * t * (t * (t * 6 - 15) + 10);  
     }  
     function lerp(t, a, b) {  
       return a + t * (b - a);  
     }  
     function grad(hash, x, y, z) {  
       var h = hash & 15;  
       var u = h < 8 ? x : y, v = h < 4 ? y : h == 12 || h == 14 ? x : z;  
       return ((h&1) == 0 ? u : -u) + ((h&2) == 0 ? v : -v);  
     }  
     return {  
       noise: function (x, y, z) {  
         var floorX = ~~x, floorY = ~~y, floorZ = ~~z;  
         var X = floorX & 255, Y = floorY & 255, Z = floorZ & 255;  
         x -= floorX;  
         y -= floorY;  
         z -= floorZ;  
         var xMinus1 = x -1, yMinus1 = y - 1, zMinus1 = z - 1;  
         var u = fade(x), v = fade(y), w = fade(z);  
         var A = p[X]+Y, AA = p[A]+Z, AB = p[A+1]+Z, B = p[X+1]+Y, BA = p[B]+Z, BB = p[B+1]+Z;  
         return lerp(w, lerp(v, lerp(u, grad(p[AA], x, y, z),  
             grad(p[BA], xMinus1, y, z)),  
             lerp(u, grad(p[AB], x, yMinus1, z),  
                 grad(p[BB], xMinus1, yMinus1, z))),  
             lerp(v, lerp(u, grad(p[AA+1], x, y, zMinus1),  
                 grad(p[BA+1], xMinus1, y, z-1)),  
                 lerp(u, grad(p[AB+1], x, yMinus1, zMinus1),  
                     grad(p[BB+1], xMinus1, yMinus1, zMinus1))));  
       }  
     }  
   }  
   function generateHeight( width, height ) {  
     var data = Float32Array ? new Float32Array( width * height ) : [];  
     var perlin = new ImprovedNoise();  
     var size = width * height;  
     var quality = 2;  
     var z = Math.random() * 100;  
     for ( var i = 0; i < size; i ++ ) {  
       data[ i ] = 0  
     }  
     for ( var j = 0; j < 4; j ++ ) {  
       quality = quality * 4;  
       for ( var i = 0; i < size; i ++ ) {  
         var x = i % width;  
         var y = ~~ ( i / width );  
         data[ i ] += Math.floor( Math.abs( perlin.noise( x / quality, y / quality, z ) * 0.5 ) * quality + 10 );  
       }  
     }  
     return data;  
   }  
   var data = generateHeight(10,10);  
   for ( var i = 0; i < 100; i ++ ) {  
     var x = i % 10;  
     var y = ~~ ( i / 10 );  
     document.write(data[i]+";");  
     if (x == 10) {  
       document.writeln("<br>");  
     }  
   }  

Some more text...

ANSI and UTF-8 without BOM

Java expects that textfiles doesn't have any BOMs.

From Wikipedia, the byte order mark (BOM) is a Unicode character used to signal the endianness (byte order) of a text file or stream. Its code point is U+FEFF. BOM use is optional, and, if used, should appear at the start of the text stream. Beyond its specific use as a byte-order indicator, the BOM character may also indicate which of the several Unicode representations the text is encoded in.


// FEFF because this is the Unicode char represented by the UTF-8 byte order mark (EF BB BF). Java-Representation of a BOOM

public static final String UTF8_BOM = "\uFEFF";

IF the file right in front of you doesn't containt any special characters, there is no difference between a ANSI-Version of the file.

If you want to read a File with a BOM in Java have a look at
http://www.rgagnon.com/javadetails/java-handle-utf8-file-with-bom.html

Reading Userdata from ADS in Javascript

Reading data of a user The following snipped can be used on Windows-OS (not in browsers).
Simply execute it in a console.

 function einlesenAnwenderDaten (pUserID) {  
  //Verbindung mit ADS aufnehmen  
  var objDSE = GetObject("LDAP://rootDSE")  
  var objConnection = new ActiveXObject("ADODB.Connection");  
  objConnection.Provider = "ADsDSOObject"  
  objConnection.Open();  
  var objCommand = new ActiveXObject("ADODB.Command")  
  objCommand.ActiveConnection = objConnection  
  //Directory nach userid durchsuchen  
  var strSQL = "SELECT cn, sn, givenname, title, telephoneNumber, mail,department,company " +   
       "FROM 'LDAP://" + objDSE.Get("defaultNamingContext") + "' " +   
       "WHERE objectCategory='person' and cn = '" + pUserID + "' ";  
  objCommand.CommandText = strSQL;  
  var adodbRecordSet = objCommand.Execute();  
  WScript.Echo(adodbRecordSet.RecordCount + " Datensätze gefunden.");  
  while (!adodbRecordSet.EOF) {  
      WScript.Echo("Noch kein EOF");  
      if (adodbRecordSet.Fields("cn")!=null) {  
           WScript.Echo("cn: "+adodbRecordSet.Fields("cn"));  
      }  
      if (adodbRecordSet.Fields("Company")!=null) {  
           WScript.Echo("Company: "+adodbRecordSet.Fields("Company"));  
      }  
      if (adodbRecordSet.Fields("department")!=null) {  
           WScript.Echo("department: "+adodbRecordSet.Fields("department"));  
      }  
      if (adodbRecordSet.Fields("givenname")!=null) {  
           WScript.Echo("givenname: "+adodbRecordSet.Fields("givenname"));  
      }  
      if (adodbRecordSet.Fields("mail")!=null) {  
           WScript.Echo("mail: "+adodbRecordSet.Fields("mail"));  
      }  
      adodbRecordSet.MoveNext();  
  }  
 }  
 einlesenAnwenderDaten("UGVNUM");  

PATH manipulation via VBS or JavaScript

Sometimes it is not possible to edit the PATH variable on your Computer. - In my case the admin blocked the panel - but my user has sufficient rights to do so.
Be carefull. Do save your Environment variable somewhere in a textfile.
It is possible to damage your system.

You can call the script with the cscript scripting host.
Don't forget to reopen a new Shell to see the result of your effort.
The current Command-Shell does not show any differece

the following script is in VBScript. But you can translate it easily to Javascript.

'************************************************************
'* Modifying The System Path With New Entries *
'************************************************************
Dim ExistingPath, NewPath
Set oShell = WScript.CreateObject("WScript.Shell")
Set oEnv = oShell.Environment("SYSTEM")

'************************************************************
'* Add your Path Entry Here *
'************************************************************
ExistingPath = oEnv("PATH")
NewPath = ExistingPath & ";" & "C:\ADD SOME PATH HERE"
oEnv("PATH") = NewPath 'WRITE NEW PATH, INCLUDING OLD ONE

Sending email via Javascript

If you want to automaticly be notified by a script sending emails is a good way.
This is a sample script where you can see how this is accomplished.
It is assumed that not authentification is required.

 var msg = new ActiveXObject("CDO.Message");   
 var config = new ActiveXObject("CDO.Configuration");  
 config.Fields.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2;   
 config.Fields.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "wwsmtp01.ww-intern.de";   
 config.Fields.Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25;   
 config.Fields.Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 0;   
 config.Fields.Update();  
 msg.Configuration=config;   
 msg.From="andreas.knees@ww-informatik.de";   
 msg.To="martin.niedenzu@ww-informatik.de";   
 msg.Subject="Enter Subject Here";   
 msg.TextBody = meinMailInhalt;   
 msg.Send();;  
 msg=null;   
 config=null;  

convert ANSI to UTF-8 using JavaScript

 var adTypeBinary = 1;  
 var adTypeText  = 2;  
 var bOverwrite = true;  
 var bAsASCII = false;  
 var oFS = new ActiveXObject("Scripting.FileSystemObject");  
 var sFiNa = "OPM_Mitarbeiter.csv";  
 var sFrom = "Windows-1252";  
 var sFFSpec = oFS.GetAbsolutePathName( sFiNa);  
 var oTo = new ActiveXObject( "ADODB.Stream" );  
 var sTo = "utf-8";  
 var sTFSpec = oFS.GetAbsolutePathName( sFiNa + "-utf8.txt" );  
 WScript.Echo("File name:"+sTFSpec);  
 if (oFS.FileExists( sTFSpec )) {oFS.DeleteFile(sTFSpec);};  
 var oFrom = new ActiveXObject( "ADODB.Stream" );  
 oFrom.Type = adTypeText;  
 oFrom.Charset = sFrom;  
 oFrom.Open();  
 oFrom.LoadFromFile(sFFSpec);  
 WScript.Echo(oFrom.Size + " Bytes in " + sFFSpec);  
 var oTo = new ActiveXObject( "ADODB.Stream" );  
 oTo.Type  = adTypeText;  
 oTo.Charset = sTo;  
 oTo.Open();  
 oTo.WriteText(oFrom.ReadText());  
 WScript.Echo(oTo.Size + " Bytes in " + sTFSpec);  
 var adSaveCreateNotExist = 1;  
 WScript.Echo(sTFSpec);  
 oTo.SaveToFile(sTFSpec , adSaveCreateNotExist);  
 oFrom.Close();  
 oTo.Close();  
 WScript.Echo("Das Programm ist nicht abgestürzt");  

Remove BOM in Javascript

Sometimes you need to remove the BOM from a UTF-8 File. E.g. because Java can't deal with it. So if you use Windows as your OS you can use the follwing JavaScript.
Simple execute it in a console.

 // Removes the Byte Order Mark - BOM from a text file with UTF-8 encoding  
 // The BOM defines that the file was stored with an UTF-8 encoding.  
 function RemoveBOM(filePath) {  
     // Create a reader and a writer  
         var writer,reader, fileSize;  
         var writer = new ActiveXObject("Adodb.Stream");  
         var reader = new ActiveXObject("Adodb.Stream");  
     // Load from the text file we just wrote  
         reader.Open();  
         reader.LoadFromFile( filePath);  
     // Copy all data from reader to writer, except the BOM  
         writer.Mode=3;  
         writer.Type=1;  
         writer.Open();  
         reader.position=5;  
         reader.copyto(writer,-1);  
     // Overwrite file  
         writer.SaveToFile(filePath,2);  
     // Return file name  
         RemoveBOM = filePath;  
     // Kill objects  
         var writer = null;  
         var reader = null;  
 }  
 RemoveBOM("OPM_Mitarbeiter.csv-utf8.txt");  

cscript bomremover.js