fix issue #242.

VadereSimulator/src/org/vadere/simulator/models/osm/OSMBehaviorController.java

@@ -46,11 +46,13 @@ public class OSMBehaviorController {
         VPoint currentPosition = pedestrian.getPosition();
         VPoint nextPosition = pedestrian.getNextPosition();
 
-        // start time
-        double timeOfNextStep = pedestrian.getTimeOfNextStep();
-
         // end time
-        double entTimeOfStep = pedestrian.getTimeOfNextStep() + pedestrian.getDurationNextStep();
+        double endTimeOfStep = pedestrian.getTimeOfNextStep();
+
+	    // start time
+	    double timeOfNextStep = pedestrian.getTimeOfNextStep() - pedestrian.getDurationNextStep();
+
+	    assert endTimeOfStep > timeOfNextStep && endTimeOfStep >= 0.0;
 
         if (nextPosition.equals(currentPosition)) {
             pedestrian.setTimeCredit(0);
@@ -73,7 +75,7 @@ public class OSMBehaviorController {
          * strides and foot steps have no influence on the simulation itself, i.e. they are saved to analyse trajectories
          */
         pedestrian.getStrides().add(Pair.of(currentPosition.distance(nextPosition), timeOfNextStep));
-        pedestrian.getFootSteps().add(new FootStep(currentPosition, nextPosition, timeOfNextStep, entTimeOfStep));
+        pedestrian.getFootSteps().add(new FootStep(currentPosition, nextPosition, timeOfNextStep, endTimeOfStep));
     }
 
     public void wait(PedestrianOSM pedestrian) {

VadereSimulator/src/org/vadere/simulator/models/osm/updateScheme/UpdateSchemeEventDriven.java

@@ -40,27 +40,28 @@ public class UpdateSchemeEventDriven implements UpdateSchemeOSM {
 			// event driven update ignores time credits!
 			while (pedestrianEventsQueue.peek().getTimeOfNextStep() < currentTimeInSec) {
 				PedestrianOSM ped = pedestrianEventsQueue.poll();
-				update(ped, currentTimeInSec);
+				update(ped, timeStepInSec, currentTimeInSec);
 				//System.out.println(ped.getId());
 				pedestrianEventsQueue.add(ped);
 			}
 		}
 	}
 
-	protected void update(@NotNull final PedestrianOSM pedestrian, final double currentTimeInSec) {
+	protected void update(@NotNull final PedestrianOSM pedestrian, final double timeStepInSec, final double currentTimeInSec) {
 		Event mostImportantEvent = pedestrian.getMostImportantEvent();
 
 		if (mostImportantEvent instanceof ElapsedTimeEvent) {
 			VPoint oldPosition = pedestrian.getPosition();
 
+			double stepDuration = pedestrian.getDurationNextStep();
+
 			// for the first step after creation, timeOfNextStep has to be initialized
-			/*if (pedestrian.getTimeOfNextStep() == 0) {
-				pedestrian.setTimeOfNextStep(currentTimeInSec);
-			}*/
+			if (pedestrian.getTimeOfNextStep() == 0) {
+				pedestrian.setTimeOfNextStep(currentTimeInSec - timeStepInSec);
+			}
 			
 			// this can cause problems if the pedestrian desired speed is 0 (see speed adjuster)
 			pedestrian.updateNextPosition();
-			double stepDuration = pedestrian.getDurationNextStep();
 			osmBehaviorController.makeStep(pedestrian, topography, stepDuration);
 			pedestrian.setTimeOfNextStep(pedestrian.getTimeOfNextStep() + stepDuration);
 		} else if (mostImportantEvent instanceof WaitEvent || mostImportantEvent instanceof WaitInAreaEvent) {

VadereSimulator/src/org/vadere/simulator/models/osm/updateScheme/UpdateSchemeEventDrivenParallel.java

@@ -141,7 +141,7 @@ public class UpdateSchemeEventDrivenParallel extends UpdateSchemeEventDriven {
 			parallelUpdatablePeds.stream().forEach(ped -> {
 				//logger.info(ped.getTimeOfNextStep());
 				//System.out.println(ped.getId());
-				update(ped, currentTimeInSec);
+				update(ped, timeStepInSec, currentTimeInSec);
 			});