Index: 03_drawing.html
===================================================================
--- 03_drawing.html	(revision 1747)
+++ 03_drawing.html	(revision 1748)
@@ -111,6 +111,7 @@
 <tr><td> font_family  <td> no        <td> hint: font family name for text objects (string)
 <tr><td> font_style   <td> no        <td> hint: font style for text objects (string; e.g. bold, italic)
 <tr><td> dash         <td> no        <td> dash pattern
+<tr><td> dash_period  <td> no        <td> length in coords a full dash pattern cycle
 </table>
 
 <p>{des3:17} When using a pen, the base geomerty is specified as the single, 0
@@ -121,7 +122,9 @@
 line is 2+10+2=14 units.
 
 <p>{des3:18} Dash pattern: an unsigned 16 bit integer, a bit pattern, each
-bit represents a tip sized unit in length. TODO: specify corner cases
+bit represents 1/16 dash_period long stroke, 1 means draw, 0 means invisible.
+If dash value is 0x00 or 0xFF or dash is not specified, solid stroke is drawn.
+If dash_period is not specified, it is (tip size)*128.
 
 <p id="des3:74">{des3:74} Pens are defined per group. When an object refers to a pen,
 it uses the <i>name</i> of the pen. The pen is searched first in the group of