Initial implementation of NewGRF custom signal styles

src/bridge_map.cpp

@@ -12,6 +12,7 @@
 #include "tunnelbridge_map.h"
 #include "bridge_signal_map.h"
 #include "debug.h"
+#include "newgrf_newsignals.h"
 
 #include "safeguards.h"
 
@@ -169,3 +170,36 @@ void ClearBridgeSimulatedSignalMapping()
 {
 	_long_bridge_signal_sim_map.clear();
 }
+
+btree::btree_set<uint32> _bridge_signal_style_map;
+static_assert(MAX_MAP_TILES_BITS + 4 <= 32);
+static_assert(1 << 4 <= MAX_NEW_SIGNAL_STYLES + 1);
+
+void SetBridgeSignalStyle(TileIndex t, uint8 style)
+{
+	if (style == 0) {
+		/* No style allocated before */
+		if (!HasBit(_m[t].m3, 7)) return;
+
+		auto iter = _bridge_signal_style_map.lower_bound(t << 4);
+		if (iter != _bridge_signal_style_map.end() && *iter >> 4 == t) _bridge_signal_style_map.erase(iter);
+		ClrBit(_m[t].m3, 7);
+	} else {
+		auto iter = _bridge_signal_style_map.lower_bound(t << 4);
+		if (iter != _bridge_signal_style_map.end() && *iter >> 4 == t) iter = _bridge_signal_style_map.erase(iter);
+		_bridge_signal_style_map.insert(iter, (t << 4) | style);
+		SetBit(_m[t].m3, 7);
+	}
+}
+
+uint8 GetBridgeSignalStyleExtended(TileIndex t)
+{
+	auto iter = _bridge_signal_style_map.lower_bound(t << 4);
+	if (iter != _bridge_signal_style_map.end() && *iter >> 4 == t) return (*iter) & 0xF;
+	return 0;
+}
+
+void ClearBridgeSignalStyleMapping()
+{
+	_bridge_signal_style_map.clear();
+}