Sugar's fonts

[Yuan Chao]

On 9/30/07, Bert Freudenberg <bert at freudenbergs.de> wrote:
> On Sep 30, 2007, at 16:23 , Yuan Chao wrote:
>
> > On 9/30/07, Walter Bender <walter.bender at gmail.com> wrote:
> >>>> The problem with serifs is that they often should be smaller
> >>>> than a pixel for typical screen and font sizes. Well, that is
> >>> Sure. But only in reflective mono mode.
> >> Anti-aliasing, which Linux/Pango/Cairo (hence the XO) readily
> >> supports, lets you do "sub-pixel" positioning of elements; I made a
> > Sub-pixel anti-alias rendering is provided by freetype w/o Pango/Cairo
> > since at least Redhat 8 if I remember correctly. However, it won't
> > increase the vertical resolution which is more important on serif
> > fonts that have thinner horizontal strokes than vertical ones.

> The XO display does not have sub-pixels. Vertical resolution is the
> same as horizontal, 200 dpi.
Sorry my description is confusing. Increasing horizontal resolution
with sub-pixel rendering is for normal LCD screen. XO display has
sub-pixel rendering on both direction. But in my experience, the
resolution of color mode is a bit lower due to color swizzling.
mono reflective mode:
http://picasaweb.google.com/yuanchao/OLPC/photo#5097821500215590738
mono with backlit: (set /sys/devices/platform/dcon/output to 1)
http://picasaweb.google.com/yuanchao/OLPC/photo#5098213261362528386
(I think this mode is quite useful if a hot-key can trigger it in ebook reader)
color with backlit:
http://picasaweb.google.com/yuanchao/OLPC/photo#5097821504510558050

Also according to http://wiki.laptop.org/go/Display , color mode has
slightly lower resolution.
"So a resolution rule of thumb is: 1200x900 gray (sunlit, or room with
backlight off), ~1024x768 color (room with backlight on); ~800x600
closet (total darkness). But note, even in total darkness, you have
better than 100 dpi. So when writing an activity, you basically don't
care."

On 10/1/07, Walter Bender <walter.bender at gmail.com> wrote:
> > However, it won't increase the vertical resolution
> Anti-aliasing, at least as far as I understood it from 30 years ago,
> does not impact resolution, just the positioning of elements. In any
> case, as Bert points out, there shouldn't be any difference between
> the XO's ability to render vertically vs horizontally.
I didn't mean anti-aliasing impact resolution. Just it may cause faint
strokes if they are too thin or not on grid. A higher resolution or
better hinting may solve this problem.


-- 
Best regards,
Yuan Chao