Commit a1994a53438612405c1d00d7bd9b3ef78ae477ef

Authored by Jay Berkenbilt
1 parent 88b8f8ec

Fix/clarify documentation on --rotate option (fixes #470)

Make clear that you almost always want + or - before an angle when
specifying rotation.
@@ -2,7 +2,6 @@ Candidates for upcoming release @@ -2,7 +2,6 @@ Candidates for upcoming release
2 =============================== 2 ===============================
3 3
4 * Trivial fixes: 4 * Trivial fixes:
5 - * #470: odd/even -- doc bug  
6 * #468: doc typo 5 * #468: doc typo
7 * Remove travisci 6 * Remove travisci
8 * Update manual to clearly state qpdf's exit codes including mention 7 * Update manual to clearly state qpdf's exit codes including mention
manual/qpdf-manual.xml
@@ -936,14 +936,16 @@ make @@ -936,14 +936,16 @@ make
936 <option>angle</option> portion of the parameter may be either 936 <option>angle</option> portion of the parameter may be either
937 90, 180, or 270. If preceded by <option>+</option> or 937 90, 180, or 270. If preceded by <option>+</option> or
938 <option>-</option>, the angle is added to or subtracted from 938 <option>-</option>, the angle is added to or subtracted from
939 - the specified pages' original rotations. Otherwise the pages'  
940 - rotations are set to the exact value. For example, the command  
941 - <command>qpdf in.pdf out.pdf --rotate=+90:2,4,6 939 + the specified pages' original rotations. This is almost always
  940 + what you want. Otherwise the pages' rotations are set to the
  941 + exact value, which may cause the appearances of the pages to
  942 + be inconsistent, especially for scans. For example, the
  943 + command <command>qpdf in.pdf out.pdf --rotate=+90:2,4,6
942 --rotate=180:7-8</command> would rotate pages 2, 4, and 6 90 944 --rotate=180:7-8</command> would rotate pages 2, 4, and 6 90
943 degrees clockwise from their original rotation and force the 945 degrees clockwise from their original rotation and force the
944 rotation of pages 7 through 9 to 180 degrees regardless of 946 rotation of pages 7 through 9 to 180 degrees regardless of
945 their original rotation, and the command <command>qpdf in.pdf 947 their original rotation, and the command <command>qpdf in.pdf
946 - out.pdf --rotate=180</command> would rotate all pages by 180 948 + out.pdf --rotate=+180</command> would rotate all pages by 180
947 degrees. 949 degrees.
948 </para> 950 </para>
949 </listitem> 951 </listitem>
qpdf/qpdf.cc
@@ -1276,7 +1276,9 @@ ArgParser::argHelp() @@ -1276,7 +1276,9 @@ ArgParser::argHelp()
1276 << "format as with the --pages option, described below. Repeat the option\n" 1276 << "format as with the --pages option, described below. Repeat the option\n"
1277 << "to rotate multiple groups of pages. If the angle is preceded by + or -,\n" 1277 << "to rotate multiple groups of pages. If the angle is preceded by + or -,\n"
1278 << "it is added to or subtracted from the original rotation. Otherwise, the\n" 1278 << "it is added to or subtracted from the original rotation. Otherwise, the\n"
1279 - << "rotation angle is set explicitly to the given value.\n" 1279 + << "rotation angle is set explicitly to the given value. You almost always\n"
  1280 + << "want to use + or - unless you are certain about the internals of the PDF\n"
  1281 + << "you are working with.\n"
1280 << "\n" 1282 << "\n"
1281 << "If --split-pages is specified, each page is written to a separate output\n" 1283 << "If --split-pages is specified, each page is written to a separate output\n"
1282 << "file. File names are generated as follows:\n" 1284 << "file. File names are generated as follows:\n"