OpenBve.Game.UpdateSection C# (CSharp) Method

		internal static void UpdateSection(int SectionIndex) {
			// preparations
			int zeroaspect;
			bool settored = false;
			if (Sections[SectionIndex].Type == SectionType.ValueBased) {
				// value-based
				zeroaspect = int.MaxValue;
				for (int i = 0; i < Sections[SectionIndex].Aspects.Length; i++) {
					if (Sections[SectionIndex].Aspects[i].Number < zeroaspect) {
						zeroaspect = Sections[SectionIndex].Aspects[i].Number;
					}
				} 
				if (zeroaspect == int.MaxValue) {
					zeroaspect = -1;
				}
			} else {
				// index-based
				zeroaspect = 0;
			}
			// hold station departure signal at red
			int d = Sections[SectionIndex].StationIndex;
			if (d >= 0) {
				// look for train in previous blocks
				//int l = Sections[SectionIndex].PreviousSection;
				if (Stations[d].StationType != StationType.Normal) {
					settored = true;
				}
			}
			// train in block
			if (Sections[SectionIndex].Trains.Length != 0) {
				settored = true;
			}
			// free sections
			int newaspect = -1;
			if (settored) {
				Sections[SectionIndex].FreeSections = 0;
				newaspect = zeroaspect;
			} else {
				int n = Sections[SectionIndex].NextSection;
				if (n >= 0) {
					if (Sections[n].FreeSections == -1) {
						Sections[SectionIndex].FreeSections = -1;
					} else {
						Sections[SectionIndex].FreeSections = Sections[n].FreeSections + 1;
					}
				} else {
					Sections[SectionIndex].FreeSections = -1;
				}
			}
			// change aspect
			if (newaspect == -1) {
				if (Sections[SectionIndex].Type == SectionType.ValueBased) {
					// value-based
					int n = Sections[SectionIndex].NextSection;
					int a = Sections[SectionIndex].Aspects[Sections[SectionIndex].Aspects.Length - 1].Number;
					if (n >= 0 && Sections[n].CurrentAspect >= 0) {
						a = Sections[n].Aspects[Sections[n].CurrentAspect].Number;
					}
					for (int i = Sections[SectionIndex].Aspects.Length - 1; i >= 0; i--) {
						if (Sections[SectionIndex].Aspects[i].Number > a) {
							newaspect = i;
						}
					} if (newaspect == -1) {
						newaspect = Sections[SectionIndex].Aspects.Length - 1;
					}
				} else {
					// index-based
					if (Sections[SectionIndex].FreeSections >= 0 & Sections[SectionIndex].FreeSections < Sections[SectionIndex].Aspects.Length) {
						newaspect = Sections[SectionIndex].FreeSections;
					} else {
						newaspect = Sections[SectionIndex].Aspects.Length - 1;
					}
				}
			}
			Sections[SectionIndex].CurrentAspect = newaspect;
			// update previous section
			if (Sections[SectionIndex].PreviousSection >= 0) {
				UpdateSection(Sections[SectionIndex].PreviousSection);
			}
		}

 private void UpdateFrontBackward(TrainManager.Train Train, bool UpdateTrain)
 {
     // update sections
     if (this.PreviousSectionIndex >= 0)
     {
         Game.Sections[this.PreviousSectionIndex].Enter(Train);
         Game.UpdateSection(this.PreviousSectionIndex);
     }
     if (this.NextSectionIndex >= 0)
     {
         Game.Sections[this.NextSectionIndex].Leave(Train);
         Game.UpdateSection(this.NextSectionIndex);
     }
     if (UpdateTrain)
     {
         // update train
         if (this.PreviousSectionIndex >= 0)
         {
             if (!Game.Sections[this.PreviousSectionIndex].Invisible)
             {
                 Train.CurrentSectionIndex = this.PreviousSectionIndex;
             }
         }
         else
         {
             Train.CurrentSectionLimit = double.PositiveInfinity;
             Train.CurrentSectionIndex = -1;
         }
     }
 }