+# An htb file is a zip file containing the .htm, .gif, .hhp, .hhc and .hhk
+# files, renamed to htb.
+# This can then be used with e.g. helpview.
+# Optionally, a cached version of the .hhp file can be generated with hhp2cached.
+$(DOCDIR)\htb\ogl.htb: $(DOCDIR)\html\ogl\ogl.htm
+ cd $(DOCDIR)\html\ogl
+ -erase ogl.zip ogl.htb
+ zip ogl.zip *.htm *.gif *.hhp *.hhc *.hhk
+ -mkdir $(DOCDIR)\htb
+ -erase $(DOCDIR)\htb\ogl.htb
+ -erase $(DOCDIR)\htb\ogl.htb
+ move ogl.zip $(DOCDIR)\htb\ogl.htb
+ cd $(THISDIR)