[formats] add page

site-src/computation.wtn

@@ -9,3 +9,5 @@ There are several mathematical models for expressing computation, like the {lamb
 languages.
 
 {phone-computing} — Notes on computing with a smartphone.
+
+{formats} — Notes on file formats.

site-src/formats.wtn

@@ -0,0 +1,5 @@
+* Various formats
+
+{netbpm} — The Netbpm image formats
+
+{obj} — The OBJ model format

site-src/links.wtn

@@ -0,0 +1,35 @@
+* Links
+
+** Programming
+
+{https://esoteric.codes/ Esoteric.Codes}
+{https://esolangs.org/wiki/Main_Page Esolang}
+{http://evincarofautumn.blogspot.com/2012/02/why-concatenative-programming-matters.html Why Concatenative Programming Matters}
+
+** Operating systems
+
+{https://archives.loomcom.com/genera/genera-install.html Genera}
+{https://serenityos.org/ SerenityOS}
+
+** Communities
+
+{https://tildeverse.org Tildeverse}
+{https://tilde.town/ tilde.town}
+{https://merveilles.town Merveilles}
+
+** People
+
+{https://okmij.org/ftp/ Oleg Kiselyov}
+{https://pbat.ch/ Paul Batchelor}
+{https://wiki.xxiivv.com/site/home.html XXIIVV (Devine Lu Linvega)}
+{https://susam.net/ Susam Pal}
+
+** Resources
+
+{https://learnopengl.com/ Learn OpenGL}
+{http://www.heimskringla.no/wiki/Main_Page Heimskringla}
+
+** Other
+
+{http://n-gate.com/ n-gate.com}
+{https://principiadiscordia.com/ The Principia Discordia}

site-src/obj.wtn

@@ -0,0 +1,29 @@
+* The OBJ file format
+
+OBJ is a file format for 3D models. It is line based with every line
+starting with an identifier for what the line describes. A file looks like this:
+
+``
+# comment
+o name of object
+
+# list of vertices
+v 1.000000 1.000000 -1.000000
+...
+
+# list of texture coordinates (0.0 to 1.0)
+vt 0.875000 0.500000
+...
+
+# list of vertex normals
+vn 0.0000 1.0000 0.0000
+...
+
+# face elements. these consist of indices of the previous groups. this face
+# element consists of the fifth, third, and first vertex (first number), and
+# these vertices are coupled with the first, second, and third texture
+# coordinate (second number) as well as the first vertex normal (third
+# number). note that these indices start on 1, not 0.
+f 5/1/1 3/2/1 1/3/1
+...
+``