On Fri, 28 Jan 2011, cyrille henry wrote:
for AA in a FB, i also have good result rendering 4 time the same pimitive with alpha and displaced by 1/2 pixel in each direction.
Proper AA would render 4 times the same primitive displaced by (0 0), (0 1/2), (1/2 0), and (1/2 1/2), instead, so that the 4 points form a square aligned with the pixel grid, instead of at 45°.
Also, care must be taken to ensure 25 % contribution of each layer (and not some other percentage sequence if you use a normal [alpha] with 75 % opacity in all four layers). Thus you use opacity 100 %, 50 %, 33,333 %, 25 %, from the bottom up (that's 1/n).
But in any case, it's a good idea.
_______________________________________________________________________ | Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC