Re: Using Pango for text rendering on Android

[Behdad Esfahbod <behdad behdad org>]

On 14-07-09 08:29 AM, György Kövesdi wrote:
> Hi,
>
> I have a multi-platform project which needs software rendering of
> graphical primitives (lines, circles, etc) and international text into
> memory pixmaps.
> Pango seems to be a good choice for this purpose, and it works perfectly
> for me on some different Linux platforms, including embedded devices.
> Recently I ported it to Android (based on
> http://dev.laptop.org/git/users/cscott/android-libs ) and it works fine,
> except that the initialization time is 2 minutes (!) on my fastest
> device (1.7 GHz CPU). According to debug results, the fontconfig
> initialization is guilty. It makes the application completely unusable,
> however, the rendering speed is perfect (after the initialization has
> been completed).
>
> Any ideas would be appreciated to resolve this problem.

Try fontconfig from master.  It should be significantly faster.  I also have
an experimental patch that is not good enough for merging, but should be good
enough for you to use.  Please report your findings.  Patch attached here:

  https://bugs.freedesktop.org/show_bug.cgi?id=64766#c31

Also, if you can configure fontconfig to cache the fonts on the device, that
should make it fast to start up subsequently.

> My questions are:
>
> - Is it possible to use the Android built-in Java-based font rendering?
> IMHO it would be the better solution. I found some articles about it on
> the net, but could not find real solution.

Using Android text rendering from an Android app?  Yes, I'm sure it's possible
:).  From a native app?  I don't know.


> - Can I use other font-render backends for Pango?

You can't use CoreText and Win32, so you are left with fontconfig one, unless
you are willing to write a new one.


> - Is there any similar solution other than Pango?

There's no other full solution that I know of.


-- 
behdad
http://behdad.org/