5 Known problems

A number of issues are known concerning the interoperation with various other software. Some of the known problems can be solved by moving to newer versions of the problematic software or by simple patches.

If you find something not mentioned here, please send a bug report using M-x preview-report-bug RET, which will fill in a lot of information interesting to us and send it to the bug-auctex@gnu.org list. Please use the bug reporting commands if at all possible.

5.1 Font problems with Dvips

Some fonts have been reported to produce wrong characters with preview-latex. preview-latex calls Dvips by default with the option -Pwww in order to get scalable fonts for nice results. If you are using antialiasing, however, the results might be sufficiently nice with bitmapped fonts, anyway. You might try -Ppdf for another stab at scalable fonts, or other printer definitions. Use

M-x customize-variable RET preview-fast-dvips-command RET

and

M-x customize-variable RET preview-dvips-command RET

in order to customize this.

One particular problem is that several printer setup files (typically in a file called /usr/share/texmf/dvips/config/config.pdf if you are using the -Ppdf switch) contain the G option for ‘character shifting’. This option will result in ‘fi’ being rendered as ‘£’ (British Pounds sign) in several fonts, unless your version of Dvips has a long-standing bug in its implementation fixed (only very recent versions of Dvips have).

5.2 Too small bounding boxes

The bounding box of a preview is determined by the LaTeX package using the pure TeX bounding boxes. If there is material extending outside of the TeX box, that material will be missing from the preview image. This happens for the label-showing boxes from the showkeys package. This particular problem can be circumvented by using the showlabels option of the preview package.

In general, you should try to fix the problem in the TeX code, like avoiding drawing outside of the picture with PSTricks.

One possible remedy is to set preview-fast-conversion to ‘Off’ (see The Emacs interface). The conversion will take more time, but will then use the bounding boxes from EPS files generated by Dvips.

Dvips generally does not miss things, but it does not understand PostScript constructs like \resizebox or \rotate commands, so will generate rather wrong boxes for those. Dvips can be helped with the psfixbb package option to preview (see The LaTeX style file), which will tag the corners of the included TeX box. This will mostly be convenient for pure PostScript stuff like that created by PSTricks, which Dvips would otherwise reserve no space for.

5.3 x-symbol interoperation

Thanks to the work of Christoph Wedler, starting with version ‘4.0h/beta’ of x-symbol, the line parsing of AUCTeX and preview-latex is fully supported. Earlier versions exhibit problems. However, versions before 4.2.2 will cause a drastic slowdown of preview-latex’s parsing pass, so we don’t recommend to use versions earlier than that.

If you wonder what x-symbol is, it is a package that transforms various tokens and subscripts to a more readable form while editing and offers a few input methods handy especially for dealing with math. Take a look at http://x-symbol.sourceforge.net.

x-symbol versions up to 4.5.1-beta at least require an 8bit-clean TeX implementation (meaning that its terminal output should not use ‘^^’-started escape sequences) for cooperation with preview-latex. Later versions may get along without it, like preview-latex does now.

If you experience problems with circ.tex in connection with both x-symbol and Latin-1 characters, you may need to change your language environment or, as a last resort, customize the variable LaTeX-command-style by replacing the command latex with latex -translate-file=cp8bit.

5.4 Middle-clicks paste instead of toggling

This is probably the fault of your favorite package. isearch.el is known to be affected while searches are in progress, but the code is such a complicated mess that no patch is in sight. Better just end the search with RET before toggling and resume with C-s C-s or similar afterwards. Since previews over the current match will auto-open, anyway, this should not be much of a problem in practice.

5.5 No images are displayed with gs 9.27 and earlier

preview-latex tries to adjust the foreground and background colors of generated images to those of Emacs. Unfortunately, incompatible changes introduced in Ghostscript 9.27 breaks the traditional method partially, and preview-latex can display no images under certain circumstances.

A new method implemented alternatively works only with Ghostscript > 9.27. If you are using Ghostscript 9.27 or earlier, customize the option preview-pdf-adjust-color-method.

User Option: preview-pdf-adjust-color-method

Method to adjust colors of images generated from PDF. It is not consulted when the LaTeX command produces DVI files.

When the option is t (default), preview-latex adjusts the FG and BG colors of the generated images by the new method. This method requires that Ghostscript has working DELAYBIND feature, thus is invalid with gs 9.27 (and possibly < 9.27).

When it is compatible, preview-latex uses traditional method. This option is provided for backward compatibility with older gs. See the below explanation for detail.

When nil, no adjustment is done and “black on white” image is generated regardless of Emacs color. This is provided for fallback for gs 9.27 users with customized foreground color. See the below explanation for detail.

When the LaTeX command produces PDF rather than DVI and Emacs has non-trivial foreground color, the traditional method (compatible) makes gs >= 9.27 to stop with error. Here, “non-trivial foreground color” includes customized themes.

If you use such non-trivial foreground color and the version of Ghostscript equals to 9.27, you have two options:

1. Choose the value compatible and customize preview-reference-face to have default (black) foreground color. This makes the generated image almost non-readable on dark background, so the next option would be your only choice in that case.
2. Choose the value nil, which forces plain “black on white” appearance for the generated image. You can at least read what are written in the image although they may not match with your Emacs color well.

The default value used to be compatible for short period before Ghostscript 9.50 was released but now is t.