added math signals

src/layout_store.hpp

@@ -6,6 +6,9 @@
 #include <string>
 #include <vector>
 
+#include "math_channel.hpp"
+#include "measure.hpp"
+
 namespace udpscope {
 
 /// The user-arranged part of a session, persisted per data source in
@@ -28,8 +31,28 @@ struct LayoutState {
     double offset = 0.0;
   };
   std::vector<Calibration> calibration;
+
+  /// Signals the session had enabled. Enabling is what starts acquisition, so this is what makes a
+  /// reopened scope look like the one that was closed -- and it is saved by *name*, like every other
+  /// identity here, because a CONFIG renumbers the channels.
+  std::vector<std::string> enabled;
+
+  /// The derived channels, graphs and all: the editor's work is part of the session, not of the
+  /// process. A graph is stored as one string per node so the file stays in this store's TOML
+  /// subset (tables, string arrays, scalars) rather than growing a nested-table parser for it; see
+  /// `math_node_text()` for the field order.
+  std::vector<MathChannel> math;
+
+  /// The measurements pane, by signal *name* and with the type and options a row was built with.
+  std::vector<Measure> measures;
 };
 
+/// One `MathNode` as `kind|source|in_a|in_b|gain|offset|fc|q|lo|hi|x|y`, and back. The kind is the
+/// op's *index* into `math_op_at()`, which is why the enum's order is a stored format and not just
+/// an implementation detail: reordering it renames every saved graph's operations.
+std::string math_node_text(const MathNode& node);
+bool math_node_from_text(const std::string& text, MathNode& out);
+
 /// `~/.config/udpscope/<host>_<port>.toml`, with the directory created.
 /// Characters unsafe in a filename are replaced in the host part.
 std::string layout_path(const std::string& host, std::uint16_t port);