Can deal with pickup measure based on 'metcon' in MEI (limitation: mu…

…st be the beginning measure and no ties leading to the first measure)

main/ScoreParser.cpp

@@ -69,7 +69,7 @@ ScoreParser::generateScoreFiles(string dir, string scoreName, string meiFile)
     generatedFiles.push_back(timemapFilePath);
     timemap.parse(toolkit.RenderToTimemap(option));
 
-    std::vector<string> meters; // starting from measure 1
+    std::vector<string> meters; // could start from measure 1 or 0 (pickup)
     for (int i = 0; i < int(timemap.size()); i++) {
         auto event = timemap.get<jsonxx::Object>(i);
         if (event.has<jsonxx::String>("meterSig")) {
@@ -79,12 +79,13 @@ ScoreParser::generateScoreFiles(string dir, string scoreName, string meiFile)
         }
     }
     // Writing to the .meter file
-    vector<std::pair<int, string>> meterChanges;
+    // vector<std::pair<int, string>> meterChanges;
     string outputString;
+    int offset = abs(1 - toolkit.HasPickupMeasure()); // start from measure 0 if there's pickup
     for (int m = 0; m + 1 < int(meters.size()); m++) {
         if ((m == 0) || (meters.at(m) != meters.at(m-1))) {
-            outputString += std::to_string(m+1) + "\t" + meters.at(m) + "\n";
-            meterChanges.push_back(std::pair<int, std::string>(m+1, meters.at(m)));
+            outputString += std::to_string(m+offset) + "\t" + meters.at(m) + "\n";
+            // meterChanges.push_back(std::pair<int, std::string>(m+offset, meters.at(m)));
         }
     }
     string outfile(dir + "/" + scoreName + ".meter");
@@ -100,7 +101,7 @@ ScoreParser::generateScoreFiles(string dir, string scoreName, string meiFile)
     }
 
     // Calculating cumulative fraction for the beginning of each measure
-    vector<vrv::Fraction> cumulativeMeasureFraction;
+    vector<vrv::Fraction> cumulativeMeasureFraction; // note that this is updated later if there is a pickup measure
     if (meters.size() > 0)  cumulativeMeasureFraction.push_back(vrv::Fraction(0, 1));
     for (int m = 1; m < int(meters.size()); m++) {
         cumulativeMeasureFraction.push_back(cumulativeMeasureFraction.back() + vrv::Fraction::fromString(meters.at(m-1)));
@@ -170,9 +171,37 @@ ScoreParser::generateScoreFiles(string dir, string scoreName, string meiFile)
         if (b.on < a.on)    return false;
         if (a.pitch < b.pitch)  return true;
         if (b.pitch < a.pitch)  return false;
-        return false; // not sure why "return trule" wouldn't also work here.
+        return false; // not sure why "return true" would not also work here.
     });
 
+    // Dealing with possible pickup measure by adjusting the initial measure and shifting other meaasures
+    // Note that cumulative fractions also need adjustments, but lines do not need to be resorted.
+    if (toolkit.HasPickupMeasure() && int(meters.size()) > 1) {
+        vrv::Fraction M = vrv::Fraction::fromString(meters.at(0));
+        vrv::Fraction L; // the actual length of the pickup measure. (TODO: not accurate if tied across the first measure)
+        for (const auto &line : lines) {
+            if (line.measureIndex == 1) {
+                L = line.cumulative;
+            }
+        }
+        for (int m = 1; m < int(meters.size()); m++) // adjusting cumulativeMeasureFraction
+            cumulativeMeasureFraction.at(m) = cumulativeMeasureFraction.at(m) - (M-L);
+
+        for (auto &line : lines) {
+            if (line.measureIndex > 1) {
+                line.measureIndex--;
+                line.cumulative = line.cumulative - (M-L);
+            } else { // line.measureIndex == 1
+                line.measureIndex = 0;
+                line.beat = (M-L) + line.cumulative;
+                if (line.cumulative == L) { // (TODO: might not be accurate if tied across the first measure)
+                    line.beat = vrv::Fraction(0, 1);
+                    line.measureIndex = 1;
+                }
+            }
+        }
+    }
+
     // Writing to the .solo file
     string content;
     for (const auto &line : lines) {

verovio-replace/include/vrv/toolkit.h

@@ -716,6 +716,8 @@ class Toolkit {
 
 
     // Yucong Jiang
+
+    bool HasPickupMeasure();
 
     Fraction GetClosestFraction(float num);
 

verovio-replace/src/toolkit.cpp

@@ -1950,6 +1950,26 @@ std::string Toolkit::GetMIDIValuesForElement(const std::string &xmlId)
 
 // Yucong Jiang
 
+bool Toolkit::HasPickupMeasure() {
+    jsonxx::Object elements;
+    elements.parse(GetElementsAtTime(0)); // beginning measure
+    if (elements.has<jsonxx::String>("measure")) {
+        std::string measureID = elements.get<jsonxx::String>("measure");
+        jsonxx::Object attributes;
+        attributes.parse(GetElementAttr(measureID));
+        if (attributes.has<jsonxx::String>("metcon")) {
+            if (attributes.get<jsonxx::String>("metcon") == "false") {
+                return true; // has pickup measure
+            }
+        } else {
+            return false; // no pickup measure
+        }
+    }
+
+    return false;
+}
+
+
 Fraction Toolkit::GetClosestFraction(float num) {
     int numerator, denominator;
     if ((num-0) < 1e-6) {
@@ -1966,7 +1986,7 @@ Fraction Toolkit::GetClosestFraction(float num) {
 Fraction Toolkit::GetCumulativeFraction(int measure, Fraction pos, const std::vector<std::pair<int, std::string>> meterChanges) {
     // meterChanges[stoppingIndex] is the largest meter that's not later than measure
     int i = 0, stoppingIndex = 0;
-    while (i < meterChanges.size()) {
+    while (i < int(meterChanges.size())) {
         if (meterChanges.at(i).first > measure) {
             stoppingIndex = i - 1;
             break;
@@ -1977,7 +1997,7 @@ Fraction Toolkit::GetCumulativeFraction(int measure, Fraction pos, const std::ve
             i++;
         }
     }
-    if (i == meterChanges.size()) {
+    if (i == int(meterChanges.size())) {
         stoppingIndex = i - 1;
     }