improved perfs and event management

src/waveform.cpp

@@ -272,7 +272,11 @@ bool load_waveform_into_model(ScopeModel& model, const std::string& path,
   }
   model.set_target_span(reader.rows() * (dt > 0.0 ? dt : 0.001));
   model.set_signals(std::move(signals));
-  for (std::size_t i = 0; i < reader.names().size(); ++i) model.set_signal_enabled(i, true);
+  // All of them in one call: one re-plan, hence one allocation of the buffer, where a loop
+  // of single enables planned it once per column (see `set_signals_enabled`).
+  std::vector<std::size_t> all(reader.names().size());
+  for (std::size_t i = 0; i < all.size(); ++i) all[i] = i;
+  model.set_signals_enabled(all, true);
 
   const std::size_t channels = model.channels().size();
   if (channels == 0) {