Alexei, I don't know about others on the list. But I find the linear algebra / bezier discussion very interesting and I'm happy to discuss those.
The new algorithm is pretty simple, yes. BTW, I wonder if the 1/8th of pixel tolerance is what's causing this: https://lists.cairographics.org/archives/cairo/2008-May/014149.html 1/8th of a pixel sounds too large of an error for a 256-level rasterizer. b On Fri, May 24, 2019 at 9:42 AM Alexei Podtelezhnikov <apodt...@gmail.com> wrote: > > Similarly, if FreeType had performance tracking bots it would be easy to > follow the benefits of a performance improvement and such decisions would > be come more data driven. > > Dominik, > > You point is well taken, but benchmarking FreeType is hard even > considering that rendering is the bottleneck. This is because there is > often too many moving parts, too many simple and incredibly complex > fonts to choose from, too many use cases. No single number is probably > sufficient, instead I look at each individual components: flattening a > single Bezier segment (cubic and conic separately), rendering a line, > composing the image, etc. I actually use 'perf to see how the shares > of a function of interest changes. This is incredibly tedious work. I > do use "ftbench -b c" too to get an integral number (it is not like we > do not have anything, we do have ftbench). You are welcome to hit me > over the head if "ftbench -b c" deteriorates, so that your complains > are also data driven. > > Case in point: Bezier bisections have not been touched in more than 10 > years. I myself could not imagine that I would improve them by 20-30%. > Then I spent an evening tweaking them and probably (just probably) > found something that makes sense in C and performs well. Do you think > I would find somebody to talk to meanwhile? Do you think this is more > interesting than discussing SVG? I doubt. This is quite boring. I only > like to work on FreeType rendering because it is so reach in linear > algebra, not because I enjoy programming. Bezier flattening is about > linear algebra. Shall we go into the weeds? Most algorithms that you > can find are all correct subject to a certain threshold condition. I > think what I committed is incredibly simple computationally, so that > it will be hard to beat in performance. It is again my gut feeling > with a couple of percents in performance improvement. > > The previous algorithms survived for 6-10 years. I don't think this is > too frequent to rebase your incredibly useful testing framework. > > Alexei > > _______________________________________________ > Freetype-devel mailing list > Freetype-devel@nongnu.org > https://lists.nongnu.org/mailman/listinfo/freetype-devel > -- behdad http://behdad.org/
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