Codegen paths from python for the arm and build the graph

We now have a bunch of really cool paths in C++.  They look pretty good.

Change-Id: I9590d771cebc64cd520ceed2617aca8a82f78362
diff --git a/y2018/control_loops/python/graph_codegen.py b/y2018/control_loops/python/graph_codegen.py
new file mode 100644
index 0000000..2df9a33
--- /dev/null
+++ b/y2018/control_loops/python/graph_codegen.py
@@ -0,0 +1,175 @@
+from __future__ import print_function
+import sys
+import numpy
+import graph_generate
+
+
+def index_function_name(name):
+    return "%sIndex" % name
+
+
+def path_function_name(name):
+    return "Make%sPath" % name
+
+
+def add_edge(cc_file, name, segment, index, reverse):
+    cc_file.append("  // Adding edge %d" % index)
+    if reverse:
+        cc_file.append(
+            "  trajectories->emplace_back(Path::Reversed(%s()), 0.005);" %
+            (path_function_name(str(name))))
+    else:
+        cc_file.append(
+            "  trajectories->emplace_back(%s(), 0.005);" %
+            (path_function_name(str(name))))
+
+    start_index = None
+    end_index = None
+    for point, name in graph_generate.points:
+        if (point == segment.start).all():
+            start_index = name
+        if (point == segment.end).all():
+            end_index = name
+
+    if reverse:
+        start_index, end_index = end_index, start_index
+
+    cc_file.append("  edges.push_back(SearchGraph::Edge{%s(), %s()," %
+                   (index_function_name(start_index),
+                    index_function_name(end_index)))
+    cc_file.append(
+        "                     trajectories->back().path().length()});"
+    )
+
+    # TODO(austin): Allow different vmaxes for different paths.
+    cc_file.append(
+        "  trajectories->back().OptimizeTrajectory(alpha_unitizer, vmax);"
+    )
+    cc_file.append("")
+
+
+def main(argv):
+    cc_file = []
+    cc_file.append(
+        "#include \"y2018/control_loops/superstructure/arm/generated_graph.h\""
+    )
+    cc_file.append("")
+    cc_file.append("#include <memory>")
+    cc_file.append("")
+    cc_file.append(
+        "#include \"y2018/control_loops/superstructure/arm/trajectory.h\"")
+    cc_file.append(
+        "#include \"y2018/control_loops/superstructure/arm/graph.h\"")
+    cc_file.append("")
+    cc_file.append("namespace y2018 {")
+    cc_file.append("namespace control_loops {")
+    cc_file.append("namespace superstructure {")
+    cc_file.append("namespace arm {")
+
+    h_file = []
+    h_file.append(
+        "#ifndef Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_ARM_GENERATED_GRAPH_H_")
+    h_file.append(
+        "#define Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_ARM_GENERATED_GRAPH_H_")
+    h_file.append("")
+    h_file.append("#include <memory>")
+    h_file.append("")
+    h_file.append(
+        "#include \"y2018/control_loops/superstructure/arm/trajectory.h\"")
+    h_file.append(
+        "#include \"y2018/control_loops/superstructure/arm/graph.h\"")
+    h_file.append("")
+    h_file.append("namespace y2018 {")
+    h_file.append("namespace control_loops {")
+    h_file.append("namespace superstructure {")
+    h_file.append("namespace arm {")
+
+    # Now dump out the vertices and associated constexpr vertex name functions.
+    for index, point in enumerate(graph_generate.points):
+        h_file.append("")
+        h_file.append("constexpr uint32_t %s() { return %d; }" %
+                      (index_function_name(point[1]), index))
+        h_file.append(
+            "inline ::Eigen::Matrix<double, 2, 1> %sPoint() {" % point[1])
+        h_file.append(
+            "  return (::Eigen::Matrix<double, 2, 1>() << %f, %f).finished();"
+            % (numpy.pi / 2.0 - point[0][0], numpy.pi / 2.0 - point[0][1]))
+        h_file.append("}")
+
+    # Add the Make*Path functions.
+    h_file.append("")
+    cc_file.append("")
+    for name, segment in list(enumerate(graph_generate.unnamed_segments)) + [
+        (x.name, x) for x in graph_generate.named_segments
+    ]:
+        h_file.append(
+            "::std::unique_ptr<Path> %s();" % path_function_name(name))
+        cc_file.append(
+            "::std::unique_ptr<Path> %s() {" % path_function_name(name))
+        cc_file.append("  return ::std::unique_ptr<Path>(new Path({")
+        for point in segment.ToThetaPoints():
+            cc_file.append("      {{%.12f, %.12f, %.12f," %
+                           (numpy.pi / 2.0 - point[0],
+                            numpy.pi / 2.0 - point[1], -point[2]))
+            cc_file.append("        %.12f, %.12f, %.12f}}," %
+                           (-point[3], -point[4], -point[5]))
+        cc_file.append("  }));")
+        cc_file.append("}")
+
+    # Now create the MakeSearchGraph function.
+    h_file.append("")
+    h_file.append("// Builds a search graph.")
+    h_file.append("SearchGraph MakeSearchGraph("
+                  "::std::vector<Trajectory> *trajectories,")
+    h_file.append("                            "
+                  "const ::Eigen::Matrix<double, 2, 2> &alpha_unitizer,")
+    h_file.append("                            double vmax);")
+    cc_file.append("SearchGraph MakeSearchGraph("
+                   "::std::vector<Trajectory> *trajectories,")
+    cc_file.append("                            "
+                   "const ::Eigen::Matrix<double, 2, 2> &alpha_unitizer,")
+    cc_file.append("                            " "double vmax) {")
+    cc_file.append("  ::std::vector<SearchGraph::Edge> edges;")
+
+    index = 0
+    segments_and_names = list(enumerate(graph_generate.unnamed_segments)) + [
+        (x.name, x) for x in graph_generate.named_segments
+    ]
+
+    for name, segment in segments_and_names:
+        add_edge(cc_file, name, segment, index, False)
+        index += 1
+        add_edge(cc_file, name, segment, index, True)
+        index += 1
+
+    cc_file.append("  return SearchGraph(%d, ::std::move(edges));" % len(
+        graph_generate.points))
+    cc_file.append("}")
+
+    h_file.append("")
+    h_file.append("}  // namespace arm")
+    h_file.append("}  // namespace superstructure")
+    h_file.append("}  // namespace control_loops")
+    h_file.append("}  // namespace y2018")
+    h_file.append("")
+    h_file.append(
+        "#endif  // Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_ARM_GENERATED_GRAPH_H_")
+
+    cc_file.append("}  // namespace arm")
+    cc_file.append("}  // namespace superstructure")
+    cc_file.append("}  // namespace control_loops")
+    cc_file.append("}  // namespace y2018")
+
+    if len(argv) == 3:
+        with open(argv[1], "w") as hfd:
+            hfd.write("\n".join(h_file))
+
+        with open(argv[2], "w") as ccfd:
+            ccfd.write("\n".join(cc_file))
+    else:
+        print("\n".join(h_file))
+        print("\n".join(cc_file))
+
+
+if __name__ == '__main__':
+    main(sys.argv)