Hi Heiko,
d not consider the current low level interface of image inclusion as "user friendly". This should be done at macro level: graphicx/pdftex.def for plain/latex and your interface in ConTeXt.
sure (i always do a file existence test) but we're now wrapping up problems in pdftex, and there the low level interface (primitives) shoudl work without problems. I consider a faulty result file as a bug as will most naive users -)
This case is handled by LaTeX's graphics.sty, it calls the LaTeX kernel macro \IfFileExists.
something simlar happens in context
It costs a lot of time to write pi as decimal number ... ;-)
how many nanoseconds -) nothing compared to what pdftex is doing the rest of teh time
Perhaps someone will update the documentation of pdfTeX. 1pt is easier to explain as 3.141592pt: * Why not 3.14159pt: \newdimen\foo \foo=3.141592pt \showthe\foo % 3.14159pt \newdimen\bar \bar=3.14159pt \ifdim\foo=\bar \message{EQUAL} \else \message{NOT EQUAL} \fi % EQUAL * Testing for such a value implicates that then this value is forbidden for pdf page sizes. This complicates the documentation and this limitation is not necessary at all (\pdflastximagepages is much better here).
the pi points was just 'some value' ; in principle any value will do; it's not so much meant for testing but more to have something back instead of something invalid
Behaviour of pdfTeX for pdf image inclusion:
DEFAULT := -1 or 0 (see below) Continue := Continue with empty xform object with dimension 1pt x 1pt.
if PDFFileExists if PageNumber < 1 \pdflastximagepages = DEFAULT Warning "Invalid page number" Continue elsif PageNumber > \pdflastximagepages \pdflastximagepages is set Warning "Page number to large (out of range) Continue else \pdflastximagepages is set image is included fi else Warning "PDF file does not exist" \pdflastximagepages = DEFAULT Continue fi
this sounds ok to me (an option is: -1 does not exist and -2 invalid)
Thus \pdflastximagepages = DEFAULT means: "pdf file is not read" because of: * No \pdfximage command, program start * Invalid page number in previous call of \pdfximage * Call with valid page number, but pdf file does not exist.
The value DEFAULT can be discussed. I have not found in the pdf specification that pdf files with zero pages are forbidden. Therefore I would prefer "-1", but the current default at program start is "0".
A pdf file can indeed contain zero pages (for instance a xfdf file, or a file with only templates), so we should stick to <0 values Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com | www.pragma-pod.nl -----------------------------------------------------------------