This introduction was missing in the previous commit:

For the new measurements, we need more flexible canvas markup options. This
  includes the thicker circle for hovering.

  To generalize hovering, we can't rely on redrawing alone but need to use a
  pixmap to store the background as well. This creates a complex interaction
  with dragging, which the existing code cannot handle cleanly. 
  Therefore, ...

This commit changes:

- README: documented use of label in new-style measurements



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5406 99fdad57-331a-0410-800a-d7fa5415bdb3

README

@@ -445,7 +445,7 @@ Known issues:
 
 Syntax:
 
-<type> <from> <op> <to> <offset>
+<type> [<label>] <from> <op> <to> <offset>
 
 Types:
 - measxy: measure diagonally
@@ -468,3 +468,11 @@ the name of the frame followed by a dot.
 Example:
 
 measx pad.sw -> pad.se 1mm
+
+The optional label is printed directly before the distance. Example:
+
+a: vec @(0mm, 0mm)
+b: vec @(1mm, 0mm)
+measx "width = " a >> b 0mm
+
+would print "width = 1mm"