Hi Alex, thanks, this is very usefull. Can you tell which one of these measures is the closest to the effective length of a string morph? Number 4?
Thierry 2015-10-27 12:02 GMT+01:00 Aliaksei Syrel <[email protected]>: > Hi > > I'm sending it here so that it doesn't get lost. > > > There are multiple ways to measure string width. In the following examples > performance will be tested measuring 10`000 times the width of the > following string: > > *string := 'abcdefghijklmnopqrstuvwxyz 0123456789!@#$%^&*()_+'.* > > 1) The most straightforward way is to send #widthOfString: to the font. > Time to run gives around 250ms. > http://ws.stfx.eu/2Q5YA9DFTRDR > Resulting value is rounded to integer and seems to be not absolutely > correct and precise. > > 2) More complex way is to go deeper on the level of glyphs and manually > summarise the width of each character in the string sending > #getGlyphWidth: character to the font. Time to run gives around 750ms. > http://ws.stfx.eu/ETBEW1EHAAZ8 > Resulting value is float and looks like correct and precise value. > > 3) Even more complex is to use CairoFontMetricsProvider instead of font's > methods. The same as in 2nd case we measure each character. Time to run > around 350ms. > http://ws.stfx.eu/7I89DMD0ZLM3 > Resulting value is exactly the same as in the 2nd case. With almost equal > performance to 1st it is nice alternative. > > 4) One more way is to let native cairo to calculate everything for us. > Calls happen through nativeboost. Time to run around 120ms. > http://ws.stfx.eu/HYD76OMIOM7L <http://ws.stfx.eu/HYD76OMIOM7L> > As result it returns *CairoTextExtents* which allows to calculate width > and height with one call. > > Cheers, > Alex >
