Start work on algorithm document

docs/ALGORITHM.adoc

@@ -10,7 +10,75 @@
 
 = Algorithm
 
+== Data format
+
+[source]
+----
+Example: Face 2, level 23
+
+# Most significant 3 bits are for the face
+face_number = 0b010
+
+# This algorithm is always level 23
+data_bits = level * 2 = 23 * 2 = 46
+
+# The bit after the data bits is always 1
+# All subsequent bits are always 0
+
+Bit                     :  64              48               32              16             1
+                        :  |               |                |               |              |
+                        :  01001011101010001011100010010011 1001001100100l001100000000000000
+Face number             :  ^^^
+Data bits               :     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^
+Bit after data bits (1) :                                                    ^
+All remaining bits (0)  :                                                     ^^^^^^^^^^^^^^
+----
+
+[source]
+----
+All remaining bits (0)  :                                                     vvvvvvvvvvvvvv
+Bit after data bits (1) :                                                    v
+Data bits               :     vvvvvvvvvvvvvvvvvvvvvvvvvvvvv vvvvvvvvvvvvvvvvv
+Face number             :  vvv
+Bit                     :  64              48               32              16             1
+                        :  |               |                |               |              |
+                        :  01001011101010001011100010010011 1001001100100l001100000000000000
+Not represented         :                                                    ^^^^^^^^^^^^^^^
+0000 (10 bits)          :                                          ^^^^^^^^^^
+WORD1 (13 bits)         :                            ^^^^^^ ^^^^^^^
+WORD2 (13 bits)         :               ^^^^^^^^^^^^^
+WORD3 (13 bits)         :  ^^^^^^^^^^^^^
+----
+
+Alternative format (generated using link:https://github.com/luismartingarcia/protocol[protocol^])
+
+[source]
+----
+./protocol 'Face:3,Data:46,1:1,0:14?bits=32'
+ 0                   1                   2                   3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| Face|                           Data                          |
++-+-+-+                           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+|                                 |1|             0             |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+----
+
+[source]
+----
+./protocol 'WORD3:13,WORD2:13,WORD1:13,Number:10?bits=32'
+ 0                   1                   2                   3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+|          WORD3          |          WORD2          |           |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+|    WORD1    |       Number      |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+----
+
+
 == Encoding
+
 [%header,cols="2m,5a"]
 |===
 |Step |Code
@@ -193,6 +261,8 @@ fn fij_to_cellid(f: u8, s: u32, t: u32) -> u64 {
 
 |===
 
+== Wordlist
+
 ++++
 <style>
 #header, #content, #footnotes, #footer {