On Thu, Apr 14, 2022 at 4:23 AM Alexei Podtelezhnikov
<[email protected]> wrote:
>
> On Tue, Apr 12, 2022 at 9:57 AM Matsumura, George <[email protected]> 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.

A note about threads on Window: even if the mingw-w64 project provides
a pthread implementation (called winpthread) which could be useful for
multiplatform code, it is known that winpthread is a bit slower than
native Win32 threads. So I would avoid winpthread on Windows.

Vincent Torri

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