Merge pull request #769 from Csantucci/partial-turntables

Partial turntables https://blueprints.launchpad.net/or/+spec/partial-turntable

Author: cjakeman

Source/Documentation/Manual/features-route.rst

@@ -208,6 +208,18 @@ TrackShape block within the tsection.dat file. You only have to insert the diame
 the turntable and the degree step. Of course you have to take only the lines up to the 
 one preceding the one with degrees = 180.
 
+Also turntables which may rotate less than 360 degrees can be implemented, like the one in 
+the picture here below:
+
+.. image:: images/features-partial-turntable.png
+
+In this case following line has to be added at the end of the ``Turntable()`` block 
+in file ``turntables.dat`` for a turntable that can rotate only between 0 and 40 degrees::
+
+  MaxAngle ( 40 )
+
+Angles increase clockwise.
+
 Already many existing turntables have been successfully animated and many new other
 have been created. More can be read 
 `in this forum thread <http://www.elvastower.com/forums/index.php?/topic/28591-operational-turntable/>`_ .

Source/Documentation/Manual/images/features-partial-turntable.png

@@ -352,6 +352,7 @@ public class Turntable : MovingTable
         public List<float> Angles = new List<float>();
         public float StartingY = 0; // starting yaw angle
         public float ThresholdForTarget; // Threshold to check if we can now go to the target
+        public float MaxAngle = -1; // max angle extension for partial turntables (in radians)
         // Dynamic data
         public bool Clockwise; // clockwise motion on
         public bool Counterclockwise; // counterclockwise motion on
@@ -392,6 +393,7 @@ public Turntable(STFReader stf, Simulator simulator)
                     TrackShapeIndex = stf.ReadIntBlock(-1);
                     InitializeAnglesAndTrackNodes();
                 }),
+                new STFReader.TokenProcessor("maxangle", ()=>{ MaxAngle = MathHelper.ToRadians(stf.ReadFloatBlock(STFReader.UNITS.None , null));}),
              });
         }
 
@@ -636,6 +638,18 @@ public override void StartContinuous(bool isClockwise)
 
         public void GeneralStartContinuous(bool isClockwise)
         {
+            if (MaxAngle > 0)
+            {
+                var positiveYAngle = YAngle >= 0 ? YAngle : YAngle + 2 * (float)Math.PI;
+                if (!isClockwise && positiveYAngle < 0.2 || isClockwise && positiveYAngle <= 2 * (float)Math.PI - MaxAngle && positiveYAngle > 0.2)
+                {
+                    Clockwise = false;
+                    Counterclockwise = false;
+                    Continuous = false;
+                    if (SendNotifications) Simulator.Confirmer.Warning(Simulator.Catalog.GetStringFmt("Turntable is at its bound, can't rotate"));
+                    return;
+                }
+            }
             if (TrainsOnMovingTable.Count > 1 || (TrainsOnMovingTable.Count == 1 && TrainsOnMovingTable[0].FrontOnBoard ^ TrainsOnMovingTable[0].BackOnBoard))
             {
                 Clockwise = false;

Source/Orts.Simulation/Simulation/Turntables.cs

@@ -1594,6 +1594,17 @@ public override void PrepareFrame(RenderFrame frame, ElapsedTime elapsedTime)
                 AnimationKey = nextKey % animation.FrameCount;
                 if (AnimationKey < 0)
                     AnimationKey += animation.FrameCount;
+                // used if Turntable cannot turn 360 degrees
+                if (Turntable.MaxAngle > 0 && AnimationKey != 0)
+                {
+                    if (AnimationKey < -SharedShape.Animations[0].FrameCount * Turntable.MaxAngle / (2 * Math.PI) + animation.FrameCount)
+                    {
+                        if (AnimationKey > 20)
+                            AnimationKey = -SharedShape.Animations[0].FrameCount * Turntable.MaxAngle / (float)(2 * Math.PI) + animation.FrameCount;
+                        else
+                            AnimationKey = 0;
+                    }
+                }
                 Turntable.YAngle = MathHelper.WrapAngle(nextKey / animation.FrameCount * 2 * (float)Math.PI);
 
                 if ((Turntable.Clockwise || Turntable.Counterclockwise || Turntable.AutoClockwise || Turntable.AutoCounterclockwise) && !Rotating)