Update dot option definitions to latest (2015)

README.md

@@ -227,6 +227,47 @@ This graph shows all loaded RGL modules:
 Look for more in
 [examples](https://github.com/monora/rgl/tree/master/examples) directory.
 
+## (Optional) Configuring DOT output options
+
+The default graph will use standard DOT output visuals.
+
+If you wish to configure the styling of the diagram we provide the methods `set_edge_options` and `set_vertex_options` for this purpose. You can use any options from the `NODE_OPTS` and `EDGE_OPTS` constants in `lib/rgl/rdot.rb`. Simply use the exact option name as an argument in your method call.
+
+You can also configure the overall appearance of the graph by passing a hash of options from `GRAPH_OPTS` to the output method. The example below shows an example of styling vertices, edges and setting some basic graph options.
+
+![colored diagram](images/styled_graph.png "Colored DOT graph")
+
+```ruby
+require 'rgl/adjacency'
+require 'rgl/dot'
+
+graph = RGL::DirectedAdjacencyGraph['a', 'b', 'b', 'c']
+
+graph.add_edge('a', 'b')
+graph.add_edge('a', 'c')
+
+# Vertex Settings
+graph.set_vertex_options('a', label: 'This is A', shape: 'box3d', fontcolor: 'green', fontsize: 16)
+graph.set_vertex_options('b', label: 'This is B', shape: 'tab', fontcolor: 'red', fontsize: 14)
+graph.set_vertex_options('c', shape: 'tab', fontcolor: 'blue')
+
+# Edge Settings
+graph.set_edge_options('a', 'b', label: 'NotCapitalEdge', style: 'dotted', direction: 'back', color: 'magenta')
+graph.set_edge_options('a', 'c', weight: 5, color: 'blue')
+
+# This hash contains the configuration for the overall graph
+# Applicable values are listed in lib/rgl/rdot.rb GRAPH_OPTS
+# The values for edge and vertex will make use of the hashes above
+graph_options = {
+    "rankdir"  => "LR",
+    "labelloc" => "t",
+    "label"    => "Graph\n (generated #{Time.now.utc})"
+}
+
+graph.write_to_graphic_file('png', 'graph', graph_options)
+
+```
+
 ## Credits
 
 Many thanks to Robert Feldt which also worked on a graph library
@@ -249,14 +290,14 @@ the module {RGL::DOT} which is used instead of Roberts module to visualize
 graphs.
 
 Jeremy Bopp, John Carter, Sascha Doerdelmann, Shawn Garbett, Andreas
-Schörk, Dan Čermák and Kirill Lashuk for contributing additions, test
+Schörk, Dan Čermák, Kirill Lashuk and Markus Napp for contributing additions, test
 cases and bugfixes.
 
 See also: https://github.com/monora/rgl/contributors
 
 ## Copying
 
-RGL is Copyright (c) 2002,2004,2005,2008,2013,2015,2019,2020,2022 by Horst
+RGL is Copyright (c) 2002,2004,2005,2008,2013,2015,2019,2020,2022,2023 by Horst
 Duchene. It is free software, and may be redistributed under the [Ruby
 license](https://en.wikipedia.org/wiki/Ruby_License) and terms specified in
 the LICENSE file.

lib/rgl/dot.rb

@@ -52,55 +52,42 @@ def to_dot_graph(params = {})
       fontsize       = params['fontsize'] ? params['fontsize'] : '8'
       graph          = (directed? ? DOT::Digraph : DOT::Graph).new(params)
       edge_class     = directed? ? DOT::DirectedEdge : DOT::Edge
-      vertex_options = params['vertex'] || {}
-      edge_options   = params['edge'] || {}
 
       each_vertex do |v|
         default_vertex_options = {
           'name'     => vertex_id(v),
           'fontsize' => fontsize,
           'label'    => vertex_label(v)
         }
-        each_vertex_options = default_vertex_options.merge(vertex_options)
-
-
-
-        vertex_options.each do |option, val|
-          each_vertex_options[option] = if val.is_a?(Proc)
-                                          if val.call(v).nil?
-                                            nil
-                                          elsif val.call(v).key?(:"#{option}")
-                                            val.call(v)[:"#{option}"]
-                                          end
-                                        else
-                                          val
-                                        end
-        end
-
-          graph << DOT::Node.new(each_vertex_options)
+        each_vertex_options = default_vertex_options
+
+        if @vertex_options && @vertex_options[v]
+          RGL::DOT::NODE_OPTS.each do |opt|
+            if @vertex_options[v].key?(:"#{opt}")
+              each_vertex_options["#{opt}"] = @vertex_options[v].fetch(:"#{opt}")
+            end
+          end
         end
+        graph << DOT::Node.new(each_vertex_options)
+      end
 
-      each_edge do |u, v|
+      edges.each do |edge|
         default_edge_options = {
-          'from'     => vertex_id(u),
-          'to'       => vertex_id(v),
+          'from'     => edge.source,
+          'to'       => edge.target,
           'fontsize' => fontsize
         }
-        each_edge_options = default_edge_options.merge(edge_options)
-
-        edge_options.each do |option, val|
-          each_edge_options[option] = if val.is_a?(Proc)
-                                        if val.call(u, v).nil?
-                                          nil
-                                        elsif val.call(u, v).key?(:"#{option}")
-                                          val.call(u, v)[:"#{option}"]
-                                        end
-                                      else
-                                        val
-                                      end
-        end
 
-            graph << edge_class.new(each_edge_options)
+        each_edge_options = default_edge_options
+
+        if @edge_options && @edge_options[edge]
+          RGL::DOT::EDGE_OPTS.each do |opt|
+            if @edge_options[edge].key?(:"#{opt}")
+              each_edge_options["#{opt}"] = @edge_options[edge].fetch(:"#{opt}")
+            end
+          end
+        end
+        graph << edge_class.new(each_edge_options)
         end
 
       graph