Re: [ft-devel] different output from 32-bit and 64bit version of gray_render_scanline

[Werner LEMBERG]

> I've found that when I compile my code for i586 or x86_64, I get
> different slightly different bitmaps using freetype.

Interesting.

> I eventually got to gray_render_scanline in src/smooth/ftgrays.c and
> noticed that we have a different implementation of
> gray_render_scanline for FT_LONG64 and !FT_LONG64.  I've been using
> v2.9, but see the same behavior on 2.9.1, 2.10, and master.  [...]
>
> So, is this a surprise to anyone?  Should the two versions behave
> identically in the absence of overflow or other extreme cases?

The behaviour should be identical, yes.  Reason for two code paths is
velocity.

> I'd be happy to continue my investigation and provide a trace or
> anything else useful to show that they behave differently.

Thank you in advance!


    Werner