sin cos LUT in HEX file

I looked at the function and I found this:

TYPE ROM IS ARRAY(0 TO 511) OF UNSIGNED(8 DOWNTO 0);
FUNCTION INIT_ROM RETURN ROM IS
VARIABLE romvar: ROM;
VARIABLE x: REAL;
begin
  for I in 0 TO 511 loop
    x:= SIN(real(i)*MATH_PI/real(511));
    romvar(i):=CONV_UNSIGNED(INTEGER(x*real(511)),9);
  end loop;
  return romvar;
end;

I think I understand how the function works but I don't understand how to interface the ROM.

The ROM I want have the cos/sin value for 0-90 degrees with a resolution of 4096 samples.

So do i set the array size to 0 to 4096 and the function will create a ROM of that size.

But how do I do when I want to read a certain address?