Optionally disable a mapping's surjective check (#14)

* Add a button to the additional settings

* Add convenience function

* Opionally do NOT check mapping surjectivity

Author: alxvth

src/AdditionalSettings.cpp

@@ -99,6 +99,7 @@ AdditionalSettingsDialog::AdditionalSettingsDialog(const mv::Dataset<Points>& cu
     mv::util::Serializable("AdditionalSettingsDialog"),
     _okButton(this, "Ok"),
     _selectionMappingSourcePicker(this, "Selection mapping source"),
+    _checkMappingSurjective(this, "Check mapping surjectivity", true),
     _currentDataGUID(this, "currentDataGUID")
 {
     setWindowTitle("Additional DE Viewer settings");
@@ -107,6 +108,8 @@ AdditionalSettingsDialog::AdditionalSettingsDialog(const mv::Dataset<Points>& cu
 
     setCurrentData(currentData);
 
+    _checkMappingSurjective.setToolTip("Only un-check this if you really know what you are doing.");
+
     connect(&_okButton, &mv::gui::TriggerAction::triggered, this, &QDialog::accept);
 
     auto* layout = new QGridLayout(this);
@@ -115,6 +118,7 @@ AdditionalSettingsDialog::AdditionalSettingsDialog(const mv::Dataset<Points>& cu
 
     layout->addWidget(_selectionMappingSourcePicker.createLabelWidget(this), ++row, 0, 1, 1);
     layout->addWidget(_selectionMappingSourcePicker.createWidget(this), row, 1, 1, -1);
+    layout->addWidget(_checkMappingSurjective.createWidget(this), ++row, 1, 1, -1);
 
     layout->addWidget(_okButton.createWidget(this), ++row, 0, 1, -1, Qt::AlignRight);
 

src/AdditionalSettings.h

@@ -63,6 +63,19 @@ bool checkSurjectiveMapping(const mv::LinkedData* linkedData, const std::uint32_
 // checks whether the mapping covers all elements in the target
 bool checkSelectionMapping(const mv::Dataset<Points>& other, const mv::Dataset<Points>& current);
 
+inline bool isMappingValid(const mv::LinkedData* selectionMapping, unsigned int numPointsTarget, const mv::Dataset<Points>& testData, bool checkSurjective = true) {
+    if (!selectionMapping)
+        return false;
+    
+    if (numPointsTarget != testData->getNumPoints())
+        return false;
+
+    if (checkSurjective)
+        return checkSurjectiveMapping(selectionMapping, numPointsTarget);
+
+    return true;
+}
+
 // 
 // AdditionalSettingsDialog
 //
@@ -87,6 +100,8 @@ class AdditionalSettingsDialog : public QDialog, public mv::util::Serializable
 
     mv::gui::DatasetPickerAction& getSelectionMappingSourcePicker() { return _selectionMappingSourcePicker; }
 
+    bool checkMappingSurjective() const { return _checkMappingSurjective.isChecked(); }
+
     std::vector<uint32_t>& getSelection(const QString& selectionName) {
         if (selectionName == "A")
             return _selectionA;
@@ -105,6 +120,7 @@ class AdditionalSettingsDialog : public QDialog, public mv::util::Serializable
 private:
     mv::gui::TriggerAction          _okButton;
     mv::gui::DatasetPickerAction    _selectionMappingSourcePicker;
+    mv::gui::ToggleAction           _checkMappingSurjective;
 
     mv::Dataset<Points>             _currentData = {};
     mv::gui::StringAction           _currentDataGUID;      // internal for serialization

src/DifferentialExpressionPlugin.cpp

@@ -398,10 +398,7 @@ void DifferentialExpressionPlugin::init()
 
             // Check if the selection mapping makes sense
             const auto [selectionMapping, numPointsTarget] = getSelectionMappingOtherToCurrent(otherData, _points);
-            const bool useOtherSelection =
-                selectionMapping != nullptr &&
-                numPointsTarget == _points->getNumPoints() &&
-                checkSurjectiveMapping(selectionMapping, numPointsTarget);
+            const bool useOtherSelection = isMappingValid(selectionMapping, numPointsTarget, _points, _additionalSettingsDialog.checkMappingSurjective());
 
             otherData->getSelection<Points>()->indices = useOtherSelection ? _additionalSettingsDialog.getSelection(selectionName) : std::vector<uint32_t>{};