Use \graphicspath to search for images

[pgf-tikz-bot]

Migrated from SourceForge
Author: *anonymous
Timestamp: 2008-08-25 17:38:22

It is quite common to use \graphicspath{{../images/}} or similar with \includegraphics. It would be nice to have pgf search in these directories for \pgfdeclareimage just like \includegraphics does.

[pgf-tikz-bot]

Migrated from SourceForge
Author: tantau
Timestamp: 2013-09-30 10:24:41.444000

• status: open --> open-accepted
• Group: --> Future

[sergiud]

I have a working implementation for this feature. The changes are already used in a complex project which also makes heavy use of TikZ externalization.

Currently, the changes are injected into \pgf@declareimage by replacing all \pgf@findfile instances by a modified version of this macro that loops over the \Ginput@path content. I explicitly avoided patching \pgf@findfile because the macro is also used by the external library which is pretty fragile. As such, the search path support is limited to \pgfdeclareimage only.

Please advise how to integrate the changes into TikZ directly.

The changes are currently loaded through a package:

% inputpath.sty
\RequirePackage{etoolbox}

\def\inputpath@pgf@findfile#1:#2+#3{%
  \ifx\Ginput@path\@empty
    % There's nothing we can loop over: pass the arguments to the original
    % command as is.
    \inputpath@old@pgf@findfile{#1}:{#2}+{#3}%
  \else
    \let\inputpath@cur\@secondoftwo
    \expandafter\@tfor\expandafter
      \inputpath@cur\expandafter:\expandafter=\Ginput@path\do{%
      \def\inputpath@filename{\inputpath@cur/#3#1}%
      \pgfutil@IfFileExists{\inputpath@filename}%
      {\xdef\pgf@filename{\inputpath@filename}%
        % Found the file. We're done.
        \@break@tfor
      }%
      {\def\pgf@mightbeempty{#2}%
        \ifx\pgf@mightbeempty\pgfutil@empty\else%
          \inputpath@pgf@findfile#2+{#3}%
        \fi
      }%
    }%
  \fi
}%

\newcommand\inputpath@pgf@declareimage@fail{%
  \PackageWarning{inputpath}{\string\pgf@declareimage\space could not be
    patched\MessageBreak
    to enable graphicx search path support.\MessageBreak
    Using \string\graphicspath\space may not extend the\MessageBreak
    image search path\@gobble}%
}

\AtEndPreamble{%
  \ifx\pgf@findfile\@undefined\else
    % Add search path support to \pgfdeclareimage
    \let\inputpath@old@pgf@findfile=\pgf@findfile
    % Uncomment the following line for debugging purposes:
    % \tracingpatches
    \PackageInfo{inputpath}%
      {Patching two occurrences of \string\pgf@findfile\space in\MessageBreak
      \string\pgf@declareimage\space for enabling\MessageBreak
      graphicx search path support\@gobble}%
    % As of TikZ/PGF 3.1.8b, \pgf@declareimage contains two calls to
    % \pgf@findfile. Both references to the original macro must be replaced.
    % Check pgfcoreimage.code.tex if patching succeeds but \pgfdeclareimage
    % still cannot locate images in the graphicx search path.
    \patchcmd\pgf@declareimage
      {\pgf@findfile}%
      {\inputpath@pgf@findfile}%
      {%
        \PackageInfo{inputpath}{Patched first occurrence of
          \string\pgf@findfile\space in\MessageBreak
          \string\pgf@declareimage\@gobble}%
        \PackageInfo{inputpath}{Patching second occurrence of
          \string\pgf@findfile\space in\MessageBreak
          \string\pgf@declareimage\@gobble}%
        \patchcmd\pgf@declareimage
          {\pgf@findfile}%
          {\inputpath@pgf@findfile}%
          {\PackageInfo{inputpath}{Successfully patched
              \string\pgf@declareimage.\MessageBreak
               It is now possible to use \string\graphicspath\space\MessageBreak
               to extend the image search path\@gobble}}%
          {\inputpath@pgf@declareimage@fail}%
      }%
      {\inputpath@pgf@declareimage@fail}%
  \fi
}

Afterwards, one can simply use

\graphicspath{{./images/ch00/}}

to extend the search path for image declarations.