question: public ccQuad3 tile ( ccGridSize pos ) { int idx = ( gridSize_ . y * pos . x + pos . y ) * 4 * 3 ; float [ ] vertArray = new float [ ccQuad3 . size ] ; for ( int i = 0 ; i < ccQuad3 . size ; i ++ ) { vertArray [ i ] = vertices . get ( idx + i ) ; } return new ccQuad3 ( vertArray ) ; }
target:  returns the tile at the given position 