[luatex] LuaTeX file almost 2.5x bigger

[Hartmut Henkel]

On Sun, 8 Aug 2010, Reinhard Kotucha wrote:

> There is probably some room for improvements.  The TJ operator
> supports kerning already quite similar to dvips, which is very
> efficient.
>
> Example (from the PDF reference manual):
>
>   [(A) 120 (W) 120 (A) 95 (Y)] TJ

that's already being used, as long as no expand change is needed. The
reason for repeated Tm is that different glyphs in a line may have
different efcode tagged to them, so that several expand switches are
needed in the same line.

> And the Th operator supports horizontal scaling.
>
> I think that a lot of space can be saved if these operators are used
> instead of the TextMatrix.

yes, one could try this. I refrained from using Th as it's not entirely
clear yet how the absolute horizontal PDF position is incrementally
updated when using Th []TJ Th []TJ sequences, in particular with mixed
horizontal and vertical typesetting. This would need some experimenting.
With the absolute position reset done be Tm it's rather safe.

Regards, Hartmut