[ADD/WIP] Add test LaTeX support.

LaTeX support isn't complete, it's merely a test.

latex.py

@@ -0,0 +1,35 @@
+# Converts a TeX file into a PNG/SVG file.
+template = r"""
+\documentclass{{standalone}}
+    \usepackage{{amsmath}}
+    % TODO: Add user packages here.
+\begin{{document}}
+    % The user content goes here.
+    {content}
+
+\end{{document}}
+"""
+
+
+def render(user: str, source: str, png: bool = True) -> str:
+    import tempfile
+    import subprocess
+
+    fmt = template.format(content=source)
+
+    tmp = tempfile.NamedTemporaryFile(delete=False)
+    print(tmp.name)
+    tmp.write(bytes(fmt, encoding="utf8"))
+    tmp.close()
+    # Parse our templated file thru' LaTeX and dvipng.
+    # TODO: Allow arbitrary DPI and foreground color.
+    subprocess.run(["latex", tmp.name], cwd="/tmp")
+    if png:
+        print("PNG")
+        subprocess.run(["dvipng", "-D", "1000", tmp.name + ".dvi", "-bg", "Transparent",
+                       "-fg", "rgb .75 .75 .75", "-o", tmp.name + ".png"], cwd="/tmp")
+
+        return tmp.name + ".png"
+
+    # TODO:
+    raise NotImplementedError("SVG support is not currently implemented")