I am trying to copy data within same buffer using glCopyBufferSubData().

array[24];

glCopyBufferSubData(GL_ARRAY_BUFFER,GL_ARRAY_BUFFE R,sizeof(array)/2,0,sizeof(array)) ;

glVertexAttribPointer(index,3, GL_FLOAT, GL_FALSE, 0,&array[12]);

glDrawElements();


Above code doesn't seem to work.

Any suggestions ?