Тест на перпендикулярность

Canvas.cpp

@@ -136,6 +136,11 @@ bool Canvas::areAlreadyParallel(Line* l1, Line* l2)
     return parallelPairs.count(makeOrderedPair<LinePair>(l1, l2));
 }
 
+bool Canvas::areAlreadyPerpendicular(Line* line1, Line* line2)
+{
+    return perpendicularPairs.count(makeOrderedPair<LinePair>(line1, line2));
+}
+
 // ===================================================================
 // Методы работы с ограничениями
 // ===================================================================
@@ -443,6 +448,52 @@ void Canvas::mousePressEvent(QMouseEvent* event)
         update();
         return;
     }
+
+    else if (mode == Mode::Perpendicular) {
+        Line* found = findAt(scene);
+
+        if (!found) {
+            current_line = nullptr;
+            update();
+            return;
+        }
+
+        // Первый клик: выбираем первую линию
+        if (!current_line) {
+            current_line = found;
+            update();
+            return;
+        }
+
+        // Повторный клик на ту же линию: сброс выбора
+        if (found == current_line) {
+            current_line = nullptr;
+            update();
+            return;
+        }
+
+        if (!areAlreadyPerpendicular(found, current_line)) {
+            auto pair = makeOrderedPair<LinePair>(found, current_line);
+            sys.addConstraintPerpendicular(*found, *current_line, constraints_count++);
+            perpendicularPairs.insert(pair);
+
+            current_line = nullptr;
+            mode = Mode::None;
+            after_constraint = true;
+            update();
+        }
+        else {
+
+            QMessageBox::warning(this,
+                QString("Wrong"),
+                QString("Perpendicular lines can not be more perpendicular!"),
+                QMessageBox::Ok
+            );
+            current_line = nullptr;
+            update();
+            return;
+        }
+    }
 }
 
 void Canvas::mouseMoveEvent(QMouseEvent* event)