Issue 39 LaTeX math support

[dakusui]

This is a pull request that offers an implementation of Issue-#39 (LaTeX math mode support)

README

Usage and syntax

Command line

(snip)

 -e,--encoding <ENCODING>       The encoding of the input file.
 -h,--html                      In this case the input is an HTML file.
                                The contents of the <pre
                                class="textdiagram"> tags are rendered as
                                diagrams and saved in the images directory
                                and a new HTML file is produced with the
                                appropriate <img> tags.
    --help                      Prints usage help.
-L,--latex-math                 Enable LaTeX math mode.

(snip)

Syntax

(snip)

LaTeX mode.

If you place LaTeX formulae inside 2 $s, it will be rendered using jlatexmath. That is, if you have a following input files.

$Box_1$                    $Box^2$
+---------------------+    +------+   /---------\
|$\sum_{i=0}^{n}x^i$  |    |$cBLU$|   |         |
|                     +--->|cRED  +-=-+cGRE$C_k$|
|{io}                 |    |cXYZ  |   |{o}      |
+----------+----------+    +---+--+   \---------/
           |                   |
           |                   :
           |                   V
           |           +-------------------+
           +---------->*$A_i$ hello $B^i$  |
                       |              +----+
                       |              |c8FA|
                       +--------------+----+

$|Set| = o-*-Freunde-*-nicht=*=diese-=-*- * töne$

o Quick brown fox jumps over
* a lazy dog.

$Q_u^i$, $C_k$, $B_r^{own}$, $F_{ox}$ jumps

over a lazy $d\cdot\frac{o}{g}$.


$\forall x \in X, \quad \exists y \leq \epsilon$


$\sin A \cos B =$

    $ \frac{1}{2}\left[ \sin(A-B)+\sin(A+B) \right]$


$\frac{d}{dx}\left( \int_{0}^{x} f(u)\,du\right)=f(x).$


 $v \sim \mathcal{N} (m,\sigma^2)$

This will be rendered as follows.

Limitations

This feature is only available when you are generating .png files.

Discussions

• This enhancement introduces a new semantics to a certain character in a text and it means potentially hurts a compatibility. And for this product, we need keep the backward compatibility because there are quite a few users who use ditaa as automatic document generation backend. Thus, this feature must be disabled by default.
• .svg support is discussed separately in Issue-44.

Tasks

• Implement tests
• Fix a bug where * is rendered as a bullet point (or a connector?) even if it is placed inside $ and $.
• Remove pom.xml
  • Backport chages made in pom.xml to project.clj
• Provide a documentation.
• Implement an option to enable this feature. This must be disabled by default.
• Make tests work under leiningen.

[dakusui]

This change was intended to run JUnit based tests with lein test.

[dakusui]

After introducing lein-junit, which executes JUnit based tests under test/java directory, I realized existing tests are not passing since we do not have resources under tests directory but in test-resources directory.
These changes will make those tests work again.

[dakusui]

@stathissideris , I believe this pull request is ready to merge.
Please feel free to ask me if anything unclear.

[torbsorb]

Hi, I would very much welcome a merge of this PR!

[dakusui]

Seems like we need to resolve the conflict.
Let me take a look.

[dakusui]

I resolved the conflict by moving the modification made by Toni Dietze Flupp@users.noreply.github.com in SVGBuilder.java to DiagramText.java.
The change is found here. : f2e613a?diff=unified&w=1
(Please note that my IDE formatted the file. If you don't prefer it, please let me know.)

[dakusui]

I could figure out a way to remove unnecessary changes introduced by my IDE.
I think the PR is now ready for merge.
In case you find anything, please let me know.