problem with glMapBuffer()

OpenGL Development JOGL Development
#1

hello,

this is my code for loading a texture into a pbo. The call to glMapBuffer returns null. Just wandering if anyone can see my error.

init


gl.glBindBuffer(GL.GL_PIXEL_UNPACK_BUFFER_ARB, 0);
gl.glTexImage2D(GL.GL_TEXTURE_2D, 0, GL.GL_RGB, tileWidth, tileHeight, 0,
	        		GL.GL_BGRA, GL.GL_UNSIGNED_BYTE, null);

gl.glGenBuffersARB(TILE_COUNT_Y * TILE_COUNT_X, texturePixelId, 0);

gl.glBindBufferARB(GL.GL_PIXEL_UNPACK_BUFFER_ARB, texturePixelId[count]);
gl.glBufferDataARB(GL.GL_PIXEL_UNPACK_BUFFER_ARB, texture.getPixels().capacity(), texture.getPixels(),
					GL.GL_STREAM_DRAW_ARB);
ByteBuffer bufferster = gl.glMapBuffer(GL.GL_PIXEL_UNPACK_BUFFER_ARB, GL.GL_WRITE_ONLY_ARB);
bufferster.put((ByteBuffer)texture.getPixels());
gl.glUnmapBuffer(GL.GL_PIXEL_UNPACK_BUFFER_ARB);

thanks for any help