Trouble with glVertexArray and glDrawElements

Hi.

My first Jogl testes by manually drawing polygons (via glBegin, glVertex3f and so on) work fine. :-)
However using the faster glVertexPointer() and then glDrawElements() doesn't do anything, except to throw exceptions to me after a while. :-(
From my former Gl4java tests I got the vertex array and the connection array. However moving this code to Jogl fails for me so far.
What am I doing wrong? Any hints appreciated. :-)

Here's the relevant part:

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// SIZE_FLOAT = 4
// SIZE_SHORT = 2

/** In some initialisation method */

// float mypoints[]   : holds each vertex (x, y, z)
ByteBuffer bbuffer = ByteBuffer.allocateDirect(mypoints.length * SIZE_FLOAT);
for (short i = 0; i < mypoints.length; i++) {
  bbuffer.putFloat(mypoints[i]);
}
bbuffer.rewind();
bufPoints = bbuffer.asFloatBuffer();

// short conns[]   : holds (0, 1, 2), (1, 2, 3) and so on.
ByteBuffer bbuffer = ByteBuffer.allocateDirect(conns.length * SIZE_SHORT);
for (short i = 0; i < conns.length; i++) {
  bbuffer.putShort(conns[i]);
}
bbuffer.rewind();
bufConns = bbuffer.asShortBuffer();

// and so on for colours, etc. The Buffers should be OK.


/** Now in the diplay() method */


gl.glEnableClientState(gl.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, gl.GL_FLOAT, 0, bufPoints);
// similar to colours, etc.
gl.glDrawElements(gl.GL_TRIANGLES, bufConns.limit(), gl.GL_SHORT, bufConns);

Do I have to use "gl.GL_UNSIGNED_SHORT" or "gl.GL_SHORT" in the DrawElements-call? None of them work for me. ;-)

By the way: do I really have to specify the Float_Size (4 Bytes on many machines) and Short_Size (2 bytes on many machines) ? However: if my Java application is to run on a platform where I don't know its Float_Size?

Greetings and thank you.

-ric

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