aa_shift
int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
return (cover * master_alpha + aa_mask) >> aa_shift;
aa_scale = 1 << aa_shift,
aa_scale = 1 << aa_shift,
int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
aa_scale = 1 << aa_shift,
int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
aa_scale = 1 << aa_shift,