glRotatef(angle, 0, 0, 1.0f);
ByteBuffer new_mapped_buffer = glMapBufferARB(GL_ARRAY_BUFFER_ARB,
GL_WRITE_ONLY_ARB,
mapped_buffer);
if ( new_mapped_buffer != mapped_buffer )
mapped_float_buffer = new_mapped_buffer.order(ByteOrder.nativeOrder()).asFloatBuffer();
mapped_buffer = new_mapped_buffer;
mapped_float_buffer.rewind();
vertices.rewind();
mapped_float_buffer.put(vertices);
if ( glUnmapBufferARB(GL_ARRAY_BUFFER_ARB) )