add splitter filters to ui

src/lib/sim/BeltSystem.cpp

@@ -89,6 +89,22 @@ void BeltSystem::setSplitterFilters(QPoint tile,
     it->second.filterB = filterB;
 }
 
+std::optional<BeltSystem::SplitterInfo> BeltSystem::getSplitterInfo(QPoint tile) const
+{
+    const std::map<std::pair<int, int>, SplitterTile>::const_iterator it =
+        m_splitters.find(key(tile));
+    if (it == m_splitters.end())
+    {
+        return std::nullopt;
+    }
+    return SplitterInfo{
+        it->second.outputA,
+        it->second.outputB,
+        it->second.filterA,
+        it->second.filterB
+    };
+}
+
 // ---------------------------------------------------------------------------
 // Port interface
 // ---------------------------------------------------------------------------

src/lib/sim/BeltSystem.h

@@ -52,6 +52,15 @@ public:
                             const std::vector<ItemType>& filterA,
                             const std::vector<ItemType>& filterB);
 
+    struct SplitterInfo
+    {
+        Rotation outputA;
+        Rotation outputB;
+        std::vector<ItemType> filterA;
+        std::vector<ItemType> filterB;
+    };
+    std::optional<SplitterInfo> getSplitterInfo(QPoint tile) const;
+
     // -- Port interface (buildings <-> belts) --------------------------------
     // port.tile      = the belt tile adjacent to the building
     // port.direction = direction items flow on that tile