add dia to the supported figure generation tools for the tutorial; clean up

doc/tutorial/Makefile

@@ -7,15 +7,16 @@ CONVERT = convert
 CSS = --css-include=tutorial.css
 SPLIT = --split section
 
+DIA_SOURCES = buffer.dia pp.dia dumbbell.dia star.dia
 TGIF_SOURCES = packet.obj helpers.obj 
-DIA_SOURCES = buffer.dia 
+
+DIA_EPS = ${DIA_SOURCES:.dia=.eps}
+DIA_PNG = ${DIA_SOURCES:.dia=.png}
+DIA_PDF = ${DIA_SOURCES:.dia=.pdf}
 
 TGIF_EPS = ${TGIF_SOURCES:.obj=.eps}
 TGIF_PNG = ${TGIF_SOURCES:.obj=.png}
 TGIF_PDF = ${TGIF_SOURCES:.obj=.pdf}
-DIA_EPS = ${DIA_SOURCES:.dia=.eps}
-DIA_PNG = ${DIA_SOURCES:.dia=.png}
-DIA_PDF = ${DIA_SOURCES:.dia=.pdf}
 
 all:  images html split-html pdf
 
@@ -24,12 +25,12 @@ all:  images html split-html pdf
 #        buffer may be needed (xorg-x11-server-Xvfb) to provide a "fake"
 #        display
 images:
-	cd figures/; $(TGIF) -print -png $(TGIF_SOURCES) 
-	cd figures/; $(TGIF) -print -eps $(TGIF_SOURCES) 
-	cd figures/; $(foreach FILE,$(TGIF_EPS),$(EPSTOPDF) $(FILE);)
 	cd figures/; $(DIA) -t png $(DIA_SOURCES) 
 	cd figures/; $(DIA) -t eps $(DIA_SOURCES) 
 	cd figures/; $(foreach FILE,$(DIA_EPS),$(EPSTOPDF) $(FILE);)
+	cd figures/; $(TGIF) -print -png $(TGIF_SOURCES) 
+	cd figures/; $(TGIF) -print -eps $(TGIF_SOURCES) 
+	cd figures/; $(foreach FILE,$(TGIF_EPS),$(EPSTOPDF) $(FILE);)
 
 html: images
 	$(TEXI2HTML) ${CSS} tutorial.texi

doc/tutorial/figures/README

@@ -1,10 +1,14 @@
 Please write image files in a vector graphics format, when possible, and
 generate the .png and .pdf versions on the fly (see ../Makefile).  
 
-Recommended tools are dia, tgif, and xfig.  Store the .dia, .obj, or .fig 
-versions in mercurial, but not the .png or .pdfs.  If the figure is
-not available in a vector graphics format, store a .png and a .pdf version
-here.
+Currently supported tools are dia and tgif.  xfig could be added similarly
+if someone wants to add it.  The main requirement for adding another format
+is that the tool to edit it is freely available and that a cron script can 
+autogenerate the pdf and png from the figure source.
+
+Store the .dia, or .obj versions in mercurial, but not the .png or .pdfs.  
+If the figure is not available in a vector graphics format, store both
+a .png and a .pdf version in this directory.
 
 If you add a source (.dia, .obj) file here, remember to add it to
 the list of figure sources in the Makefile in the directory above

doc/tutorial/other.texi

@@ -34,7 +34,7 @@ see this point-to-point network, you can think of an RS-422 (or RS-232 for
 you old-timers) cable.  This topology is shown below.
 
 @sp 1
-@center @image{pp,,,,png}
+@center @image{figures/pp,,,,png}
 
 @cindex CreateObject
 @cindex InternetNode
@@ -173,7 +173,7 @@ a file for you in the @code{tutorial} directory called @code{tutorial-star.cc}
 that implements a simple star network as seen below.
 
 @sp 1
-@center @image{star,,,,png}
+@center @image{figures/star,,,,png}
 
 In order to create a star network, we need to be able to instantiate some
 number (greater than one) of net devices on a node.  In the name of simplicity
@@ -506,7 +506,7 @@ configured with a lower bandwidth than the bus elements to provide a
 The following is a representation of the topology.
 
 @sp 1
-@center @image{dumbbell,,,,png}
+@center @image{figures/dumbbell,,,,png}
 
 We have provided a file that constructs this dumbbell network and creates 
 enough data flowing across the choke point that some packets will be dropped.