Am Donnerstag, den 11.06.2009, 23:31 +0200 schrieb Vladimir 'phcoder' Serbinenko: > On Thu, Jun 11, 2009 at 12:28 PM, Felix Zielcke<fziel...@z-51.de> wrote: > > Am Montag, den 09.02.2009, 08:24 -0800 schrieb Colin D Bennett: > >> On Mon, 9 Feb 2009 15:11:16 +0100 > >> Robert Millan <r...@aybabtu.com> wrote: > >> > >> > On Sun, Feb 08, 2009 at 01:49:53PM -0800, Colin D Bennett wrote: > >> > > This patch greatly—*tremendously*, even, if higher-numbered Unicode > >> > > characters are used—speeds up retrieving a glyph for a particular > >> > > Unicode character. This makes text rendering in general much faster. > >> > > > >> > > My text benchmark shows the new text rendering speed is somewhere from > >> > > 2.6x to 31x of the previous speed. Basically, PFF2 font files are now > >> > > required to have the character index ordered in ascending order of code > >> > > point. > >> > > > >> > > Fonts created by 'grub-mkfont' already satisfy this requirement. Fonts > >> > > created by my old Java 'fonttool' do not, and cannot be used any > >> > > longer. > >> > > > >> > > The font loader verifies that fonts fulfill the character ordering > >> > > requirement, refusing to load invalid fonts, but the primary change is > >> > > in the 'find_glyph()' function, which now uses a binary search rather > >> > > than a linear search to find the glyph. > >> > > >> > Very nice! > >> > > >> > With this patch, how does retrieving glyphs from the complete unicode > >> > font > >> > compare to retrieving glyphs (without the patch) from the ascii ascii > >> > one? > >> > >> Here is the result of my benchmark with two kinds of text: > >> (1) 104 characters of ASCII English text, and > >> (2) 104 Unicode characters randomly selected from the characters in > >> unifont, uniformly distributed over all 61050 characters in the > >> font. > >> > >> Also, I ran the tests with both the 'ascii.pf2' and 'unicode.pf2' font > >> files generated by GRUB's Makefile. Here are the results: > >> > >> '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' > >> 9 February 2009 videotest bench, text rendering > >> benchmark 640x480 resolution > >> ASCII Text Unicode Text > >> Algorithm Unifont used (Chars/s) (Chars/s) > >> --------------- ------------- ---------- ------------ > >> Linear search ASCII Font 255113 12098 [1] > >> Linear search Unicode Font 250874 23068 [2] > >> Binary search ASCII Font 255746 96231 [1] > >> Binary search Unicode Font 255113 194741 [2] > >> > >> [1] Note that using the ASCII font for Unicode text results in a > >> performance hit because the grub_font_draw_string() function will > >> use font fallback to search for the missing glyphs in another > >> font. I had other fonts loaded while running the benchmark, so > >> GRUB had to scan them for the missing characters. > >> > >> [2] These numbers, for full Unicode text with the full unifont, show > >> the improvement in worst-case performance when using the binary > >> search versus linear search. > >> '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' > >> > >> Note that most of the time is now spent actually rendering the bitmaps > >> on screen (instead of retrieving glyphs from the font), which actually > >> takes longer for the Unicode text because many of the glyphs are wider > >> than the English ASCII characters. > >> > >> (BTW, is there any way to run GRUB in a profiler? I'd like to know > >> where the graphics performance bottlenecks are.) > >> > >> > Can we make unicode font the default now? > >> > >> I think so. Using the full Unicode font does not seem to have a > >> significant effect on rendering speed now. I will commit the patch if > >> it looks OK to you. > >> > > > > Now that Vladimir finally commited this, should we make it now the > > default or not? > I think we can make unicode fonts default now. Don't get too > overexcited though: we still lack ligatures. I don't know if composing > accents work and no bidi.But this subset is already enough to support > all European languages, Chinese, Korean and Japanese as long > characters are precomposed
So if there still won't come up objections against this, then I'll do the change, then at least an Ubuntu bug report can be closed. -- Felix Zielcke _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
