BLI: add library to simplify writing dot graph exporters

See D6799 for some examples on how to use the library.

Reviewers: sergey

Differential Revision: https://developer.blender.org/D6799

1 files changed, 305 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/dot_export.cc b/source/blender/blenlib/intern/dot_export.cc
new file mode 100644
index 00000000000..96de4056fc5
--- /dev/null
+++ b/source/blender/blenlib/intern/dot_export.cc
@@ -0,0 +1,305 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <iomanip>
+
+#include "BLI_dot_export.hh"
+
+namespace BLI {
+namespace DotExport {
+
+/* Graph Building
+ ************************************************/
+
+Node &Graph::new_node(StringRef label)
+{
+  Node *node = new Node(*this);
+  m_nodes.append(std::unique_ptr<Node>(node));
+  m_top_level_nodes.add_new(node);
+  node->set_attribute("label", label);
+  return *node;
+}
+
+Cluster &Graph::new_cluster(StringRef label)
+{
+  Cluster *cluster = new Cluster(*this);
+  m_clusters.append(std::unique_ptr<Cluster>(cluster));
+  m_top_level_clusters.add_new(cluster);
+  cluster->set_attribute("label", label);
+  return *cluster;
+}
+
+UndirectedEdge &UndirectedGraph::new_edge(NodePort a, NodePort b)
+{
+  UndirectedEdge *edge = new UndirectedEdge(a, b);
+  m_edges.append(std::unique_ptr<UndirectedEdge>(edge));
+  return *edge;
+}
+
+DirectedEdge &DirectedGraph::new_edge(NodePort from, NodePort to)
+{
+  DirectedEdge *edge = new DirectedEdge(from, to);
+  m_edges.append(std::unique_ptr<DirectedEdge>(edge));
+  return *edge;
+}
+
+void Cluster::set_parent_cluster(Cluster *new_parent)
+{
+  if (m_parent == new_parent) {
+    return;
+  }
+  else if (m_parent == nullptr) {
+    m_graph.m_top_level_clusters.remove(this);
+    new_parent->m_children.add_new(this);
+  }
+  else if (new_parent == nullptr) {
+    m_parent->m_children.remove(this);
+    m_graph.m_top_level_clusters.add_new(this);
+  }
+  else {
+    m_parent->m_children.remove(this);
+    new_parent->m_children.add_new(this);
+  }
+  m_parent = new_parent;
+}
+
+void Node::set_parent_cluster(Cluster *cluster)
+{
+  if (m_cluster == cluster) {
+    return;
+  }
+  else if (m_cluster == nullptr) {
+    m_graph.m_top_level_nodes.remove(this);
+    cluster->m_nodes.add_new(this);
+  }
+  else if (cluster == nullptr) {
+    m_cluster->m_nodes.remove(this);
+    m_graph.m_top_level_nodes.add_new(this);
+  }
+  else {
+    m_cluster->m_nodes.remove(this);
+    cluster->m_nodes.add_new(this);
+  }
+  m_cluster = cluster;
+}
+
+/* Utility methods
+ **********************************************/
+
+void Graph::set_random_cluster_bgcolors()
+{
+  for (Cluster *cluster : m_top_level_clusters) {
+    cluster->set_random_cluster_bgcolors();
+  }
+}
+
+void Cluster::set_random_cluster_bgcolors()
+{
+  float hue = rand() / (float)RAND_MAX;
+  float staturation = 0.3f;
+  float value = 0.8f;
+  this->set_attribute("bgcolor", color_attr_from_hsv(hue, staturation, value));
+
+  for (Cluster *cluster : m_children) {
+    cluster->set_random_cluster_bgcolors();
+  }
+}
+
+/* Dot Generation
+ **********************************************/
+
+std::string DirectedGraph::to_dot_string() const
+{
+  std::stringstream ss;
+  ss << "digraph {\n";
+  this->export__declare_nodes_and_clusters(ss);
+  ss << "\n";
+
+  for (const std::unique_ptr<DirectedEdge> &edge : m_edges) {
+    edge->export__as_edge_statement(ss);
+    ss << "\n";
+  }
+
+  ss << "}\n";
+  return ss.str();
+}
+
+std::string UndirectedGraph::to_dot_string() const
+{
+  std::stringstream ss;
+  ss << "graph {\n";
+  this->export__declare_nodes_and_clusters(ss);
+  ss << "\n";
+
+  for (const std::unique_ptr<UndirectedEdge> &edge : m_edges) {
+    edge->export__as_edge_statement(ss);
+    ss << "\n";
+  }
+
+  ss << "}\n";
+  return ss.str();
+}
+
+void Graph::export__declare_nodes_and_clusters(std::stringstream &ss) const
+{
+  ss << "graph ";
+  m_attributes.export__as_bracket_list(ss);
+  ss << "\n\n";
+
+  for (Node *node : m_top_level_nodes) {
+    node->export__as_declaration(ss);
+  }
+
+  for (Cluster *cluster : m_top_level_clusters) {
+    cluster->export__declare_nodes_and_clusters(ss);
+  }
+}
+
+void Cluster::export__declare_nodes_and_clusters(std::stringstream &ss) const
+{
+  ss << "subgraph cluster_" << (uintptr_t)this << " {\n";
+
+  ss << "graph ";
+  m_attributes.export__as_bracket_list(ss);
+  ss << "\n\n";
+
+  for (Node *node : m_nodes) {
+    node->export__as_declaration(ss);
+  }
+
+  for (Cluster *cluster : m_children) {
+    cluster->export__declare_nodes_and_clusters(ss);
+  }
+
+  ss << "}\n";
+}
+
+void DirectedEdge::export__as_edge_statement(std::stringstream &ss) const
+{
+  m_a.to_dot_string(ss);
+  ss << " -> ";
+  m_b.to_dot_string(ss);
+  ss << " ";
+  m_attributes.export__as_bracket_list(ss);
+}
+
+void UndirectedEdge::export__as_edge_statement(std::stringstream &ss) const
+{
+  m_a.to_dot_string(ss);
+  ss << " -- ";
+  m_b.to_dot_string(ss);
+  ss << " ";
+  m_attributes.export__as_bracket_list(ss);
+}
+
+void AttributeList::export__as_bracket_list(std::stringstream &ss) const
+{
+  ss << "[";
+  m_attributes.foreach_item([&](StringRef key, StringRef value) {
+    if (StringRef(value).startswith("<")) {
+      /* Don't draw the quotes, this is an html-like value. */
+      ss << key << "=" << value << ", ";
+    }
+    else {
+      ss << key << "=\"" << value << "\", ";
+    }
+  });
+  ss << "]";
+}
+
+void Node::export__as_id(std::stringstream &ss) const
+{
+  ss << '"' << (uintptr_t)this << '"';
+}
+
+void Node::export__as_declaration(std::stringstream &ss) const
+{
+  this->export__as_id(ss);
+  ss << " ";
+  m_attributes.export__as_bracket_list(ss);
+  ss << "\n";
+}
+
+void NodePort::to_dot_string(std::stringstream &ss) const
+{
+  m_node->export__as_id(ss);
+  if (m_port_name.has_value()) {
+    ss << ":" << m_port_name.value();
+  }
+}
+
+std::string color_attr_from_hsv(float h, float s, float v)
+{
+  std::stringstream ss;
+  ss << std::setprecision(4) << h << ' ' << s << ' ' << v;
+  return ss.str();
+}
+
+NodeWithSocketsRef::NodeWithSocketsRef(Node &node,
+                                       StringRef name,
+                                       ArrayRef<std::string> input_names,
+                                       ArrayRef<std::string> output_names)
+    : m_node(&node)
+{
+  std::stringstream ss;
+
+  ss << "<<table border=\"0\" cellspacing=\"3\">";
+
+  /* Header */
+  ss << "<tr><td colspan=\"3\" align=\"center\"><b>";
+  ss << ((name.size() == 0) ? "No Name" : name);
+  ss << "</b></td></tr>";
+
+  /* Sockets */
+  uint socket_max_amount = std::max(input_names.size(), output_names.size());
+  for (uint i = 0; i < socket_max_amount; i++) {
+    ss << "<tr>";
+    if (i < input_names.size()) {
+      StringRef name = input_names[i];
+      if (name.size() == 0) {
+        name = "No Name";
+      }
+      ss << "<td align=\"left\" port=\"in" << i << "\">";
+      ss << name;
+      ss << "</td>";
+    }
+    else {
+      ss << "<td></td>";
+    }
+    ss << "<td></td>";
+    if (i < output_names.size()) {
+      StringRef name = output_names[i];
+      if (name.size() == 0) {
+        name = "No Name";
+      }
+      ss << "<td align=\"right\" port=\"out" << i << "\">";
+      ss << name;
+      ss << "</td>";
+    }
+    else {
+      ss << "<td></td>";
+    }
+    ss << "</tr>";
+  }
+
+  ss << "</table>>";
+
+  m_node->set_attribute("label", ss.str());
+  m_node->set_shape(Attr_shape::Rectangle);
+}
+
+}  // namespace DotExport
+}  // namespace BLI