svg2latex

Producing diagrams for incorporation into LaTeX documents is... difficult. There are many partial solutions, and this is mine.

Basic Use

This tool is not standalone, and has been written only to fit into my own workflow. It places a heavy burden on the user.

1. Install the textext Inkscape extension.
2. Create a figure. Use textext for any text you want to include. You should be able to place the text in the correct location in Inkscape, and expect it to appear in the same place in the final output. (Note: currently, transforming the textext element with anything other than a translation is not supported).
3. Save the file (as an Inkscape SVG).
4. Run svg2latex on the file to produce a PDF and a LaTeX file.
5. In your document, use the \input command to include the LaTeX file (you don't need to directly include the PDF file; it's referenced from the LaTeX file).

If you want to use non-textext text in your figure, then:

1. Install the cm-unicode fonts, and use them in your document.
2. Be careful about text size -- if you want to adjust the size of text, use the font size, don't just scale the text element.
3. Be careful about text alignment -- svg2latex should respect the left/center/right alignment setting of text, so if you need things to line up along an edge or line up with a connecting arrow, then you should be careful to choose the appropriate text alignment. If you have the correct alignment, then you should be able to edit the text without it moving to a stupid position.
4. Be careful about text size and space. The final rendered output won't be exactly the same size as what you see in Inkscape, so you'll need to check the output and make adjustments.
5. You can rotate normal text elements, and they should be correctly rotated in the final output.

You can have both textext elements and normal SVG text in the same document, and they will all be extracted (put into the LaTeX output and excluded from the PDF output). Unfortunately, textext output is scaled, so the font sizes won't match normal SVG text.

To Do

• Add some kind of support for rotations and scaling of textext text.
• Use a proper matrix decomposition on the accumulated transform matrix (or at least the top left 2x2 corner of it) to determine scale factor(s) and rotation angle. This should allow more strangely transformed text (e.g., skewed text) to be supported.
• Investigate an alternate approach, which is to render the textext elements separately (so that they are rendered in the same context used by textext itself) and then perform some kind of PDF merge operation to combine them with the (text-free) PDF exported by Inkscape.

Why I made this tool

I create my diagrams in Inkscape. Inkscape is pretty bad, but it's still nicer to use than xfig, and it's nicer (for me, for some tasks) than creating diagrams in text using tikz.

Inkscape includes various export methods, one of which is PDF+LaTeX. When you export to PDF, there is a checkbox you can tick to tell it to exclude text from the PDF and create a matching tex file that uses a LaTeX picture environment to embed the PDF (with \includegraphics) and overlay nice LaTeX-typeset text.

Unfortunately, if you're using Inkscape's PDF+LaTeX export, then you can't see at design time how the text is going to be typeset. For some placements this doesn't matter, because you can still get the text's anchor point into the right position quite easily and a bit of stretch or shrink in the final output compared to what you see in Inkscape is not a big deal. However, if your text includes a lot of mathematical notation (even including lone references to variables, which I find is quite common when I'm putting labels on things), then the text you see in Inkscape will be very different from the final rendered text, because the text in Inkscape will have (La)TeX math-mode code in it. This makes it harder than it should be to lay out the figure neatly, because a) you don't know how big your text is going to be, and b) all the math mode stuff gets in the way and often extends over other parts of your figure because it's significantly longer than the actual typeset maths.

But then I found an Inkscape extension called textext:

[textext](http://pav.iki.fi/software/textext/) ([textext on bitbucket](https://bitbucket.org/pv/textext))

textext approaches the problem from the opposite direction. Instead of taking Inkscape text and turning it into LaTeX code to be typset, it takes LaTeX code and renders it with pdflatex, immediately embedding the result back into your Inkscape document (and retaining the original LaTeX code in a custom attribute so that you can edit it).

This is fantastic, because instead of seeing your LaTeX code in the Inkscape window, you see the exact correct rendered LaTeX output, and you can move it around and place it as a block. The LaTeX code itself is edited through a simple dialog window created by the extension.

But... although it's great when you're creating the figure, it's still not good for the final final PDF output, because the conversion from LaTeX to PDF to SVG (Inkscape) and then (presumably) back to PDF to be embedded into a LaTeX document as a figure means that the text is no longer treated as text, but instead decays into plain old filled outline shapes, which are meaningless as far as the computer or a PDF viewing application is concerned. I would imagine that process also results in an increase in data size and probably also a reduction in rendering efficiency, but I don't know for sure.

My solution is to add yet another step to the process, which is to make a custom SVG to PDF+LaTeX converter. This does the same job as the built in Inkscape PDF+LaTeX export method, but is extended so that it understands the custom attributes used by the textext extension.

The result is that both normal Inkscape text, and rendered LaTeX text that has been embedded using textext are excluded from the PDF part and included in the LaTeX picture environment part. Those parts will then all be re-rendered by LaTeX when the two pieces are combined during final document rendering. This means that all the text is kept in text form in the PDF, so it can be selected and copied and so on.

What's more, since LaTeX's typesetting is (reasonably) stable, the rendered text that you see in Inkscape matches extremely closely with the final output, which means that you can properly design and lay out your figures in Inkscape!