Re: GSoC 2022: Alternative Rendering Engines

[Alexei Podtelezhnikov]

On Tue, Apr 12, 2022 at 9:57 AM Matsumura, George <gm960420@ohio.edu> wrote:
> The blog post mentions "a large constant factor because it’s doing
> complicated exact-area calculations for each pixel" as a performance
> impediment when drawing into the accumulation buffer. If one were
> willing to settle for fewer gray levels in the resulting image, could
> something like multisampling be used to eliminate the need for these
> area calculations entirely, especially given that SIMD is already being
> used to exploit parallelism? I'm sure there's a reason why this isn't
> done, but if someone could enlighten me as to exactly why I would highly
> appreciate it.

There are basically two approaches to rendering: Windows does
multisampling, the rest of the world integrates. I do not want to make
any claims about the speed of the either approach. There are claims
out there that other renderers beat FreeType using parallelism by the
expected factor equal to the number of CPUs, maybe more, maybe less.So
we want to see if we can borrow some of those approaches. The main
reason why FreeType is very careful about adopting alternative
approaches is ultra-portability of FreeType to pretty much anything
under the Sun because of pure C89 or C99. The performance non-parallel
rendering is not bad. Also, you can do parallelism on levels above
FreeType and outside of its control.

Alexei