Re: [ft-devel] how to compute maxp.maxStackElements?

[Cosimo Lupo]

Hi Werner,

thanks for your reply.

Yes I do run it on a range of PPEM sizes, but I always get a value somewhat less than the one from VTT, although the difference is not always the same.

I actually haven't tried to run it with different rasterizer modes though.

I'm using the default TT interpreter (40) from 2.7.0, and I simply load the each glyph for a number of PPEM sizes with the FT_LOAD_NO_BITMAP flag.

I'll see if I get different results with different rasterization modes.

Thanks again,

Cosimo

On 8 October 2016 at 17:28, Werner LEMBERG <address@hidden> wrote:

> I noticed however that the value as computed by VTT seems to be
> always a bit greater than the one I get from the code above, usually
> around 80-90 bytes greater (it varies from font to font).  I don't
> know why that is the case, and I wonder if someone else in this list
> could shed some light on this?

The stack size might depend on the used PPEM value if there is
conditional code – do you run the loop for all PPEM values from, say,
6ppem to 72ppem?  Similarly, it might depend on the used rasterizer
mode (ClearType, B/W rendering, etc.) and a lot of other things, so I
can imagine that VTT adds some bytes just to be on the safe side.


    Werner