Comping

src/vamp_zero/notation.cpp

@@ -109,9 +109,21 @@ auto vamp_zero::parse_notation_document(std::string_view json, std::string sourc
       return invalid("invalid performance duration or count-in");
     }
     document.duration = *duration;
+    auto sustain = performance.if_contains("sustain_start") ? vamp_zero::parse_beat(performance.at("sustain_start")) : duration;
+    if (!sustain || std::find(times.begin(), times.end(), rational(*sustain)) == times.end()) {
+      return invalid("invalid held-ending boundary");
+    }
+    document.sustain_start = *sustain;
+    for (auto i = std::size_t{}; i < measures->size(); ++i) {
+      auto marker = (*measures)[i].as_object().if_contains("ending_sustain");
+      auto ending = marker && marker->is_bool() && marker->as_bool();
+      if (ending != (times[i] >= rational(*sustain))) {
+        return invalid("held-ending measures disagree with performance timing");
+      }
+    }
     auto const &clicks = performance.at("clicks").as_array();
     auto click = std::size_t{};
-    for (auto measure = std::size_t{}; measure + 1 < times.size(); ++measure) {
+    for (auto measure = std::size_t{}; measure + 1 < times.size() && times[measure] < rational(*sustain); ++measure) {
       for (auto beat = times[measure]; beat < times[measure + 1]; ++beat) {
         if (click >= clicks.size()) {
           return invalid("missing metronome beat");