Correct comment on extended width and explain condensed ones too

diff --git a/bedstead.c b/bedstead.c
index 29467d59dcc7575fc875411ffb2e58d123d396ce..de3155cdb36bc01f44b619fb465f2acd5e44bf1a 100644 (file)
--- a/bedstead.c
+++ b/bedstead.c
@@ -123,8 +123,14 @@
  * and 122.9 respectively.
  *
  * 102.3 is close enough to 100 that we may as well just use square
- * pixels, which will work better on modern displays.  We round 122.9
- * to 124 so that XQTR will be precisely an integer.
+ * pixels, which will work better on modern displays.  Similarly,
+ * 122.9 is close to 125 and keeping the widths as simple fractions
+ * makes the fonts easier to work with.
+ *
+ * Double-height mode requires fonts half the usual width, hence the
+ * existence of ultra condensed and extra condensed forms.  The other
+ * two widths just fill in the gap with the obvious fractions of the
+ * normal width.
  */
 
 static struct width {