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Diffstat (limited to 'doc/context/sources/general/manuals/luatex/luatex-modifications.tex')
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diff --git a/doc/context/sources/general/manuals/luatex/luatex-modifications.tex b/doc/context/sources/general/manuals/luatex/luatex-modifications.tex index 9d3bd957e..28431fe29 100644 --- a/doc/context/sources/general/manuals/luatex/luatex-modifications.tex +++ b/doc/context/sources/general/manuals/luatex/luatex-modifications.tex @@ -257,6 +257,32 @@ which in turn triggered renaming primitives. \stopitemize +One change involves the so called xforms and ximages. In \PDFTEX\ these are +implemented as so called whatsits. But contrary to other whatsits they have +dimensions that need to be taken into account when for instance calculating +optimal linebreaks. In \LUATEX\ these are now promoted to normal nodes, which +simplifies code that needs those dimensions. + +Another reason for promotion is that these are useful concepts. Backends can +provide the ability to use content that has been rendered in several places, +and images are also common. For that reason we also changed the names: + +\starttabulate[|l|l|] +\NC \bf new name \NC \bf old name \NC \NR +\NC \type {\saveboxresource} \NC \type {\pdfxform} \NC \NR +\NC \type {\saveimageresource} \NC \type {\pdfximage} \NC \NR +\NC \type {\useboxresource} \NC \type {\pdfrefxform} \NC \NR +\NC \type {\useimageresource} \NC \type {\pdfrefximage} \NC \NR +\NC \type {\lastsavedboxresourceindex} \NC \type {\pdflastxform} \NC \NR +\NC \type {\lastsavedimageresourceindex} \NC \type {\pdflastximage} \NC \NR +\NC \type {\lastsavedimageresourcepages} \NC \type {\pdflastximagepages} \NC \NR +\stoptabulate + +There are a few \type {\pdf...} primitives that relate to this but these are +typical backend specific ones. The index that gets returned is to be considered +as \quote {just a number} and although it still has the same meaning (object +related) as before, you should not depend on that. + \stopsubsection \startsubsection[title=Changes from \ALEPH\ RC4] |