Signal Function OPP_SIG_ID_TRAINPATH

Author: Roeterdink

Source/Orts.Formats.Msts/SignalScripts.cs

@@ -78,6 +78,7 @@ public enum SCRExternalFunctions
             NEXT_SIG_ID,
             NEXT_NSIG_ID,
             OPP_SIG_ID,
+            OPP_SIG_ID_TRAINPATH,
             ID_SIG_ENABLED,
             ID_SIG_LR,
             SIG_FEATURE,

Source/Orts.Simulation/Simulation/Signalling/SIGSCRfile.cs

@@ -861,6 +861,43 @@ public int SH_function_value(SignalHead thisHead, SignalScripts.SCRScripts.SCRSt
 
                     break;
 
+                // opp_sig_id_trainpath
+
+                case SignalScripts.SCRExternalFunctions.OPP_SIG_ID_TRAINPATH:
+                    return_value = (int)thisHead.opp_sig_id_trainpath(function1);
+#if DEBUG_PRINT_ENABLED
+                    if (thisHead.mainSignal.enabledTrain != null)
+                    {
+                        File.AppendAllText(dpe_fileLoc + @"printproc.txt",
+                                " OPP_SIG_LR : Located signal : " + return_value + "\n");
+                    }
+#endif
+#if DEBUG_PRINT_PROCESS
+                    if (TDB_debug_ref.Contains(thisHead.TDBIndex) || OBJ_debug_ref.Contains(thisHead.mainSignal.thisRef))
+                    {
+                        var sob = new StringBuilder();
+                        sob.AppendFormat(" OPP_SIG_LR : Located signal : {0}", return_value.ToString());
+
+                        if (return_value > 0)
+                        {
+                            SignalObject otherSignal = thisHead.mainSignal.signalRef.SignalObjects[return_value];
+                            sob.AppendFormat(" (");
+
+                            foreach (SignalHead otherHead in otherSignal.SignalHeads)
+                            {
+                                sob.AppendFormat(" {0} ", otherHead.TDBIndex);
+                            }
+
+                            sob.AppendFormat(") ");
+                        }
+                        sob.AppendFormat("\n");
+
+                        File.AppendAllText(dpr_fileLoc + @"printproc.txt", sob.ToString());
+                    }
+#endif
+
+                    break;
+
                 // id_sig_enabled
 
                 case SignalScripts.SCRExternalFunctions.ID_SIG_ENABLED:

Source/Orts.Simulation/Simulation/Signalling/SignalHead.cs

@@ -242,6 +242,10 @@ public int opp_sig_id(SignalFunction function)
         {
             return mainSignal.opp_sig_id(function);
         }
+        public int opp_sig_id_trainpath(SignalFunction function)
+        {
+            return mainSignal.opp_sig_id_trainpath(function);
+        }
 
         public MstsSignalAspect id_sig_lr(int sigId, SignalFunction function)
         {

Source/Orts.Simulation/Simulation/Signalling/SignalObject.cs

@@ -1005,6 +1005,15 @@ public int opp_sig_id(SignalFunction function)
             return SONextSignalOpp(function);
         }
 
+        /// <summary>
+        /// opp_sig_id : returns ident of next opposite signal of required type
+        /// search using trainpath of enabled train
+        /// </summary>
+        public int opp_sig_id_trainpath(SignalFunction function)
+        {
+            return SONextSignalOppTrainpath(function);
+        }
+
         /// <summary>
         /// this_sig_noSpeedReduction : Returns the setting if speed must be reduced on RESTRICTED or STOP_AND_PROCEED
         /// returns TRUE if speed reduction must be suppressed
@@ -1664,6 +1673,51 @@ public int SONextSignalOpp(SignalFunction function)
             return signalFound;
         }
 
+        /// <summary>
+        /// Find next signal in opp direction using path of enabled train
+        /// </summary>
+        public int SONextSignalOppTrainpath(SignalFunction function)
+        {
+            int signalFound = -1;
+
+            // if enabled train is set
+            if (enabledTrain != null)
+            {
+                var pathposindex = enabledTrain.Train.PresentPosition[1].RouteListIndex;
+
+                // get route index of signal
+                var signalindex = enabledTrain.Train.ValidRoute[enabledTrain.TrainRouteDirectionIndex].GetRouteIndex(TCReference, pathposindex);
+
+                while (signalFound < 0 && signalindex >= 0)
+                {
+                    int tcindex = enabledTrain.Train.ValidRoute[enabledTrain.TrainRouteDirectionIndex][signalindex].TCSectionIndex;
+                    int direction = enabledTrain.Train.ValidRoute[enabledTrain.TrainRouteDirectionIndex][signalindex].Direction;
+                    TrackCircuitSection thisSection = signalRef.TrackCircuitList[tcindex];
+
+                    // check if required type of signal is along this section
+                    if (function == SignalFunction.NORMAL)
+                    {
+                        signalFound = thisSection.EndSignals[direction == 0 ? 1 : 0] != null ? thisSection.EndSignals[direction].thisRef : -1;
+                    }
+                    else
+                    {
+                        TrackCircuitSignalList thisListrev = thisSection.CircuitItems.TrackCircuitSignals[direction == 0 ? 1 : 0][function];
+                        if (thisListrev.TrackCircuitItem.Count > 0)
+                        {
+                            signalFound = thisListrev.TrackCircuitItem[0].SignalRef.thisRef;
+                        }
+                    }
+
+                    if (signalFound < 0)
+                    {
+                        signalindex -= 1;
+                    }
+                }
+            }
+
+            return signalFound;
+        }
+
         /// <summary>
         /// Perform route check and state update
         /// </summary>