Provide integer to SignalFunction conversion

Author: cesarBLG

Source/Orts.Formats.Msts/SignalScripts.cs

@@ -2513,6 +2513,33 @@ public SCRParameterType(SCRTermType TypeIn, int IntIn)
                 {
                     PartType = TypeIn;
                     PartParameter = IntIn;
+                    switch(IntIn)
+                    {
+                        case 0:
+                            SignalFunction = SignalFunction.NORMAL;
+                            break;
+                        case 1:
+                            SignalFunction = SignalFunction.DISTANCE;
+                            break;
+                        case 2:
+                            SignalFunction = SignalFunction.REPEATER;
+                            break;
+                        case 3:
+                            SignalFunction = SignalFunction.SHUNTING;
+                            break;
+                        case 4:
+                            SignalFunction = SignalFunction.INFO;
+                            break;
+                        case 5:
+                            SignalFunction = SignalFunction.SPEED;
+                            break;
+                        case 6:
+                            SignalFunction = SignalFunction.ALERT;
+                            break;
+                        default:
+                            SignalFunction = SignalFunction.UNKNOWN;
+                            break;
+                    }
                 }
 
                 // <summary>

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

@@ -529,10 +529,7 @@ public int SH_function_value(SignalHead thisHead, SignalScripts.SCRScripts.SCRSt
                     parameter1_value = SH_termvalue(thisHead, thisParameter,
                         localFloats, sigscr);
 
-                    if (thisParameter.SignalFunction != null)
-                    {
-                        function1 = thisParameter.SignalFunction;
-                    }
+                    function1 = thisParameter.SignalFunction;
                 }
 
                 if (thisTerm.PartParameter.Length >= 2)
@@ -541,10 +538,7 @@ public int SH_function_value(SignalHead thisHead, SignalScripts.SCRScripts.SCRSt
                     parameter2_value = SH_termvalue(thisHead, thisParameter,
                         localFloats, sigscr);
 
-                    if (thisParameter.SignalFunction != null)
-                    {
-                        function2 = thisParameter.SignalFunction;
-                    }
+                    function2 = thisParameter.SignalFunction;
                 }
             }