Auto-Scale or KeepSize ?

[tavinus]

I merged the auto-scaling code into a new branch and tested it.
It is interesting and it works. But I think it is a bit confusing and some use cases are problematic.

If you are not resizing, --scale auto will change nothing (in theory).
It will use the default 0.95 scale factor.

If you are resizing, -s auto will make the contents maintain its size while the paper increases.
If the paper is shrinking, it will actually shrink the contents more than without the -s option.

I think it is confusing because the actual default/automatic behavior is different than when someone uses -s auto.

I also like the automatic behavior being that pdfScale tries to keep the file looking the same when changing the paper size.

I think this is more like a -s keepsize (keeps content size), but then this only works when increasing the paper size, obviously. I am also not sure I like the behavior when using shrinking the paper and using -s auto. Seems off. I am thinking about renaming it from auto to keepsize or something else (suggestions welcome). I also think we can tweak this for when shrinking the paper.

Here is a sequence of files I modified with the new version. This file is a bit problematic for resizing, specially the first page. A5 decreased its paper size and A3 increased it.

$ ./pdfScale.sh ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A3 ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A3 -s auto ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A3 -s 0.95 ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A5 ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A5 -s auto ../starship_users_guide_v1.pdf
$ ./pdfScale.sh -r A5 -s 0.95 ../starship_users_guide_v1.pdf

I renamed the scaled files so we could keep both

starship_users_guide_v1.pdf
starship_users_guide_v1.SCALED.pdf
starship_users_guide_v1.A3.pdf
starship_users_guide_v1.A3.SCALED-auto.pdf
starship_users_guide_v1.A3.SCALED-095.pdf
starship_users_guide_v1.A5.pdf
starship_users_guide_v1.A5.SCALED-auto.pdf
starship_users_guide_v1.A5.SCALED-095.pdf

What do you guys think?
@boillodmanuel @yarrouye