amsmathfontsmath-mode
For some reasons of compatibility and interactivity I need to create my own simple system for drawing the formulas. (So I need standard math sybols and something like \mathcal{N}.)
I think that Unicode contains all of those symbols, but I need to draw them using some kind of pictures of symbols.
I will use it with SDL2 and OpenGL.
I'm a bit surprised that Will Robertson hasn't dropped by and mentioned the STIX fonts as these have the lowercase calligraphic (and lowercase blackboard bold) glyphs.
There doesn't yet seem to be a simple LaTeX package available mapping all the glyphs to particular commands, though. The stix package on CTAN at present seems to be just a copy of the fonts themselves (reorganised into correct texmf tree layout) but no style files as yet. I recall reading on the STIX website that LaTeX-related stuff was intended, but given how long it took the fonts to be released, I'm not holding my breath!
As of 2018, this is now quite easy using luatex or xetex:
\documentclass{article}
%\url{https://tex.stackexchange.com/q/479/86}
\usepackage{amsmath}
\usepackage{fontspec}
\usepackage{unicode-math}
\setmainfont{TeX Gyre Pagella}
% Any of the following work, and probably many more
%\setmathfont{TeX Gyre Pagella Math}
%\setmathfont{TeX Gyre Termes Math}
%\setmathfont{STIX}
\setmathfont{Asana Math}
\begin{document}
\begin{gather*}
{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
{abcdefghijklmnopqrstuvwxyz} \\
\mathcal{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathcal{abcdefghijklmnopqrstuvwxyz} \\
\mathscr{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathscr{abcdefghijklmnopqrstuvwxyz} \\
\mathbb{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathbb{abcdefghijklmnopqrstuvwxyz} \\
\end{gather*}
\end{document}
As pointed out in the comments, you need to use \mathscr (or \let\mathcal=\mathscr).
You can't use non-latin alphabets in math formulas for font reasons, even XeTeX use traditional Type1/MetaFont math fonts by default.
You can, however, use unicode-math package with OpenType math fonts:
\documentclass{article}
\usepackage{unicode-math}
\setmathfont{Latin Modern Math}
\begin{document}
$α + β + γ + δ = ε$
\[
∫f(x)dx = ∑_k Λ_k
\]
\end{document}
Best Answer
I think the font LaTeX uses depends on the
documentclassand other settings, but by default, it should be using the Computer Modern family of fonts. These can be downloaded from http://www.ctan.org/tex-archive/fonts/amsfonts/. I thinkcmsy-name like fonts contain math symbols,cmbsy-name like fonts contain bold math symbols,cmex-name like fonts even more symbols, etc. Just download the fonts and look at them in the font editor. I am no expert for fonts, but I think they are not unicode and all just support a limited set of characters. They are under the SIL Open Fonts Licencse, which should make them free for non-commercial usage (but better check this by yourself and don't quote me on that ^_^). They are not truetype, but pfb, which can be loaded in Java, for instance, but seemingly cannot be opened natively under Windows.However, unless you need your text to look exactly like LaTeX' output and/or you need to distribute the fonts with your package, I would rather recommend using unicode fonts like, e.g., Arial Unicode. Using tools like
charmap, you can find the right unicode code point for the maths symbol you like and then use that symbol. This way, you can always replace the font with another unicode font supporting the symbols.