dot: heuristic to switch between circles and ellipses

* src/twaalgos/dotty.cc: Add an option (e) to force elliptic shape, and
a heuristic to choose between circle and ellipse by default.
* src/bin/common_aoutput.cc, src/bin/dstar2tgba.cc: Document 'e'.
* src/taalgos/dotty.cc: Ignore 'e'.
* wrap/python/spot.py (setup): Do not force circular states.  The
default should be fine.
* src/tests/det.test, src/tests/dstar.test, src/tests/monitor.test,
src/tests/neverclaimread.test, src/tests/readsave.test,
src/tests/sccdot.test, src/tests/tgbagraph.test: Adjust expected
results.
* NEWS: Adjust.

NEWS

@@ -187,10 +187,12 @@ New in spot 1.99b (not yet released)
       sugar for [:*1..], and corresponds to the operator ⊕ introduced
       by Dax et al. (ATVA'09).
 
-    - GraphViz output now uses an horizontal layout by default.  The
+    - GraphViz output now uses an horizontal layout by default, and
-      --dot option of the various command-line tools takes an optional
+      also use circular states (unless the automaton has more than 100
-      parameter to fine-tune the GraphViz output (including vertical
+      states, or uses named-states).  The --dot option of the various
-      layout, round states, named automata, SCC informations, ordered
+      command-line tools takes an optional parameter to fine-tune the
+      GraphViz output (including vertical layout, forced circular or
+      elliptic states, named automata, SCC information, ordered
       transitions, and different ways to colorize the acceptance
       sets).  The environment variables SPOT_DOTDEFAULT and
       SPOT_DOTEXTRA can also be used to respectively provide a default

src/bin/common_aoutput.cc

@@ -51,13 +51,14 @@ static const argp_option options[] =
   {
     /**************************************************/
     { 0, 0, 0, 0, "Output format:", 3 },
-    { "dot", OPT_DOT, "1|a|b|B|c|f(FONT)|h|n|N|o|r|R|s|t|v",
+    { "dot", OPT_DOT, "1|a|b|B|c|e|f(FONT)|h|n|N|o|r|R|s|t|v",
       OPTION_ARG_OPTIONAL,
       "GraphViz's format (default).  Add letters for "
       "(1) force numbered states, "
       "(a) acceptance display, (b) acceptance sets as bullets, "
       "(B) bullets except for Büchi/co-Büchi automata, "
-      "(c) circular nodes, (f(FONT)) use FONT, (h) horizontal layout, "
+      "(c) force circular nodes, (e) force elliptic nodes, "
+      "(f(FONT)) use FONT, (h) horizontal layout, "
       "(v) vertical layout, (n) with name, (N) without name, "
       "(o) ordered transitions, "
       "(r) rainbow colors for acceptance sets, "

src/bin/dstar2tgba.cc

@@ -73,13 +73,14 @@ static const argp_option options[] =
       "of the given property)", 0 },
     /**************************************************/
     { 0, 0, 0, 0, "Output format:", 3 },
-    { "dot", OPT_DOT, "1|a|b|B|c|f(FONT)|h|n|N|o|r|R|s|t|v",
+    { "dot", OPT_DOT, "1|a|b|B|c|e|f(FONT)|h|n|N|o|r|R|s|t|v",
       OPTION_ARG_OPTIONAL,
       "GraphViz's format (default).  Add letters for "
       "(1) force numbered states, "
       "(a) acceptance display, (b) acceptance sets as bullets, "
-      "(B) bullets except for Büchi automata, "
+      "(B) bullets except for Büchi/co-Büchi automata, "
-      "(c) circular nodes, (f(FONT)) use FONT, (h) horizontal layout, "
+      "(c) force circular nodes, (e) force elliptic nodes, "
+      "(f(FONT)) use FONT, (h) horizontal layout, "
       "(v) vertical layout, (n) with name, (N) without name, "
       "(o) ordered transitions, "
       "(r) rainbow colors for acceptance sets, "

src/taalgos/dotty.cc

@@ -88,6 +88,7 @@ namespace spot
 	    case 'a':
 	    case 'b':
 	    case 'B':
+	    case 'e':
 	    case 'n':
 	    case 'N':
 	    case 'o':

src/tests/det.test

@@ -118,6 +118,7 @@ run 0 ../ltl2tgba -x -DC 'GFa & XGFb' > out.tgba
 cat >ex.tgba <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]

src/tests/dstar.test

@@ -61,6 +61,7 @@ run 0 ../ltl2tgba -XD dra.dstar | tee stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -82,6 +83,7 @@ run 0 ../ltl2tgba -XDD dra.dstar | tee stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -126,6 +128,7 @@ run 0 ../ltl2tgba -XDB dsa.dstar | tee stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -215,6 +218,7 @@ run 0 ../ltl2tgba -XDD dra.dstar | tee stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -264,6 +268,7 @@ digraph G {
   rankdir=LR
   label="aut.dsa"
   labelloc="t"
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]

src/tests/monitor.test

@@ -34,6 +34,7 @@ expect()
 expect ../../bin/ltl2tgba --monitor a <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 1
   0 [label="0"]

src/tests/neverclaimread.test

@@ -134,6 +134,7 @@ run 0 ../ltl2tgba -XN input > stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0", peripheries=2]

src/tests/readsave.test

@@ -349,6 +349,7 @@ digraph G {
   rankdir=LR
   label="Inf(0)&Inf(1)"
   labelloc="t"
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -367,6 +368,7 @@ digraph G {
   rankdir=LR
   label="G(Fa & Fb)\nInf(⓿)&Inf(❶)"
   labelloc="t"
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -379,7 +381,7 @@ EOF
 diff output expected
 
 
-SPOT_DOTDEFAULT=bra $ltl2tgba --dot='c.f(Lato)' 'GFa & GFb' >output
+SPOT_DOTDEFAULT=bra $ltl2tgba --dot='e.f(Lato)' 'GFa & GFb' >output
 cat output
 
 zero='<font color="#5DA5DA">⓿</font>'
@@ -389,7 +391,6 @@ digraph G {
   rankdir=LR
   label=<Inf($zero)&amp;Inf($one)>
   labelloc="t"
-  node [shape="circle"]
   fontname="Lato"
   node [fontname="Lato"]
   edge [fontname="Lato"]
@@ -515,6 +516,7 @@ digraph G {
   rankdir=LR
   label="Fin(⓿) | (Fin(❶) & Inf(❷)) | Fin(❸)"
   labelloc="t"
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   0 [label="0"]
   1 [label="1\n⓿❸"]
@@ -529,7 +531,8 @@ digraph G {
 }
 EOF
 
-# This should remove the state names
+# This should remove the state names, and automatically use circled
+# states.
 $autfilt --dot=bao1 in | grep -v '>' >out
 diff out expected2
 

src/tests/sccdot.test

@@ -76,6 +76,7 @@ digraph G {
   rankdir=LR
   label="Fin(2) & (Inf(0)&Inf(1))"
   labelloc="t"
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 1
   subgraph cluster_0 {

src/tests/tgbagraph.test

@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2014 Laboratoire de Recherche et Développement de
+# Copyright (C) 2014, 2015 Laboratoire de Recherche et Développement
-# l'Epita (LRDE).
+# de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -35,6 +35,7 @@ run 0 ../tgbagraph | tee stdout
 cat >expected <<EOF
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -50,6 +51,7 @@ digraph G {
 }
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -63,6 +65,7 @@ digraph G {
 }
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -75,6 +78,7 @@ digraph G {
 }
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]
@@ -90,6 +94,7 @@ digraph G {
 }
 digraph G {
   rankdir=LR
+  node [shape="circle"]
   I [label="", style=invis, width=0]
   I -> 0
   0 [label="0"]

src/twaalgos/dotty.cc

@@ -47,7 +47,8 @@ namespace spot
       bool opt_force_acc_trans_ = false;
       bool opt_horizontal_ = true;
       bool opt_name_ = false;
-      bool opt_circles_ = false;
+      enum { ShapeAuto = 0, ShapeCircle, ShapeEllipse }
+	opt_shape_ = ShapeAuto;
       bool opt_show_acc_ = false;
       bool mark_states_ = false;
       bool opt_scc_ = false;
@@ -123,10 +124,10 @@ namespace spot
 	      opt_bullet_but_buchi = true;
 	      break;
 	    case 'c':
-	      opt_circles_ = true;
+	      opt_shape_ = ShapeCircle;
 	      break;
-	    case 'h':
+	    case 'e':
-	      opt_horizontal_ = true;
+	      opt_shape_ = ShapeEllipse;
 	      break;
 	    case 'f':
 	      if (*options != '(')
@@ -141,6 +142,9 @@ namespace spot
 		options = end + 1;
 	      }
 	      break;
+	    case 'h':
+	      opt_horizontal_ = true;
+	      break;
 	    case 'n':
 	      opt_name_ = true;
 	      break;
@@ -275,7 +279,6 @@ namespace spot
 	    aut_->get_acceptance().used_inf_fin_sets();
 	if (opt_bullet && aut_->acc().num_sets() <= MAX_BULLET)
 	  opt_all_bullets = true;
-
 	os_ << "digraph G {\n";
 	if (opt_horizontal_)
 	  os_ << "  rankdir=LR\n";
@@ -317,8 +320,18 @@ namespace spot
 	      }
 	    os_ << "  labelloc=\"t\"\n";
 	  }
-	if (opt_circles_)
+	switch (opt_shape_)
-	  os_ << "  node [shape=\"circle\"]\n";
+	  {
+	  case ShapeCircle:
+	    os_ << "  node [shape=\"circle\"]\n";
+	    break;
+	  case ShapeEllipse:
+	    // Do not print anything.  Ellipse is
+	    // the default shape used by GraphViz.
+	    break;
+	  case ShapeAuto:
+	    SPOT_UNREACHABLE();
+	  }
 	if (!opt_font_.empty())
 	  os_ << "  fontname=\"" << opt_font_
 	      << "\"\n  node [fontname=\"" << opt_font_
@@ -452,8 +465,16 @@ namespace spot
 	if (opt_name_)
 	  name_ = aut_->get_named_prop<std::string>("automaton-name");
 	mark_states_ = !opt_force_acc_trans_ && aut_->has_state_based_acc();
+	if (opt_shape_ == ShapeAuto)
+	  {
+	    if (sn_ || aut->num_states() > 100)
+	      opt_shape_ = ShapeEllipse;
+	    else
+	      opt_shape_ = ShapeCircle;
+	  }
 	auto si =
 	  std::unique_ptr<scc_info>(opt_scc_ ? new scc_info(aut) : nullptr);
+
 	start();
 	if (si)
 	  {

wrap/python/spot.py

@@ -48,7 +48,7 @@ def setup(**kwargs):
                                            kwargs.get('fillcolor', '#ffffaa'))
 
     bullets = 'B' if kwargs.get('bullets', True) else ''
-    d = 'rcf({})'.format(kwargs.get('font', 'Lato')) + bullets
+    d = 'rf({})'.format(kwargs.get('font', 'Lato')) + bullets
     os.environ['SPOT_DOTDEFAULT'] = d
 
 # Global BDD dict so that we do not have to create one in user code.