[Gzz-commits] gzz/doc/pegboard/chug_shear_twirl--benja peg.rst

[Benja Fallenstein]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Benja Fallenstein <address@hidden>      02/11/08 13:34:28

Modified files:
        doc/pegboard/chug_shear_twirl--benja: peg.rst 

Log message:
        Define Twirl, add issue: which keybindings should be used?

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst.diff?tr1=1.2&tr2=1.3&r1=text&r2=text

Patches:
Index: gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst
diff -u gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst:1.2 
gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst:1.3
--- gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst:1.2        Wed Nov  6 
06:38:45 2002
+++ gzz/doc/pegboard/chug_shear_twirl--benja/peg.rst    Fri Nov  8 13:34:28 2002
@@ -4,8 +4,8 @@
 
 :Author:       Benja Fallenstein
 :Date-Created: 2002-11-03
-:Date:         $Date: 2002/11/06 11:38:45 $
-:Revision:     $Revision: 1.2 $
+:Date:         $Date: 2002/11/08 18:34:28 $
+:Revision:     $Revision: 1.3 $
 :Status:       Incomplete
 
 
@@ -14,6 +14,17 @@
 gives (hopefully) unambiguous specifications for them and
 assigns them key bindings.
 
+As usual, these will be optional at first; they will be activated
+by calling Gzz.py with ``--chug-shear-twirl``.
+
+
+Issues
+======
+
+- What should the key bindings be? Ctrl-C for chug could be nice,
+  and Ctrl-T for twirl could also work, but Ctrl-S is already
+  taken for saving. (Ctrl-H?)
+
 
 Chug
 ====
@@ -136,5 +147,49 @@
                               |
                               E
 
+XXX
+
+
+
+Twirl
+=====
+
+Twirl rotates a set of connections into another dimension.
+For example, with ``A`` and ``B`` marked, 'Twirl Right Down'
+works as follows::
+
+
+     Before                 After
+     ------                 -----
+
+  A - B - C - D                      A
+                             |
+                             B
+                             |
+                             C - D
+
+
+I.e., the *rightward* connections of ``A`` and ``B`` are made
+into *downward* connections. Twirl does not move the cursor.
+    
+Twirl operates on two dimensions D1 and D2, which may be equal.
+It also operates on two directions d1 and d2 (each posward
+or negward). If D1 = D2 and d1 = d2, Twirl is a no-op.
+
+The specification of Twirl on a set of cells (S) is:
+
+    - Let C be the set of connections on D1, in direction d1.
+      Each of the connections is a pair (negside, posside).
+    - Unmake all connections in C, along D1.
+    - If d1 != d2, reverse all pairs in C (exchange the first
+      and second element).
+    - Make all connections in C, this time along D2.
+
+The following precondition must be satisfied (otherwise,
+nothing is done, and an apology is rendered):
+
+    - If a cell in S has a connection on D1 in direction d1,
+      it has no connection on D2 in direction d2.
 
 
+- Benja
\ No newline at end of file