Move low speed checks to setSpeed method

Author: aoles

CHANGELOG.md

@@ -37,6 +37,8 @@ RELEASING:
 ### Added
 - Time-dependent core-based routing algorithms
 - Option to disable edge-based routing in core for a single weighting ([#928](https://github.com/GIScience/openrouteservice/issues/928))
+### Changed
+- Speed values falling below encoder's resolution are consequently stored as lowest possible non-zero value rather than being rounded to zero together with setting access to the corresponding edges to false ([#944](https://github.com/GIScience/openrouteservice/issues/944))
 ### Fixed
 - Do not consider ill-defined "maxspeed = 0" OSM tags ([#940](https://github.com/GIScience/openrouteservice/issues/940))
 - Use JSON definitions of country-specific speed limits ([#939](https://github.com/GIScience/openrouteservice/issues/939))

openrouteservice/src/main/java/org/heigit/ors/routing/graphhopper/extensions/flagencoders/VehicleFlagEncoder.java

@@ -25,6 +25,7 @@
 import com.graphhopper.routing.util.EncodingManager;
 import com.graphhopper.storage.ConditionalEdges;
 import com.graphhopper.storage.IntsRef;
+import com.graphhopper.util.BitUtil;
 import com.graphhopper.util.Helper;
 import com.graphhopper.util.PMap;
 
@@ -64,6 +65,8 @@ public abstract class VehicleFlagEncoder extends ORSAbstractFlagEncoder {
     // This value determines the speed for roads with access=destination
     protected int destinationSpeed;
 
+    protected final double minPossibleSpeed;
+
     protected Map<String, Integer> trackTypeSpeedMap;
     protected Map<String, Integer> badSurfaceSpeedMap;
     protected Map<String, Integer> defaultSpeedMap;
@@ -84,6 +87,8 @@ protected void setProperties(PMap properties) {
     VehicleFlagEncoder(int speedBits, double speedFactor, int maxTurnCosts) {
         super(speedBits, speedFactor, maxTurnCosts);
 
+        minPossibleSpeed = this.speedFactor;
+
         restrictions.addAll(Arrays.asList("motorcar", "motor_vehicle", "vehicle", "access"));
 
         restrictedValues.add("private");
@@ -230,7 +235,7 @@ public IntsRef handleWayTags(IntsRef edgeFlags, ReaderWay way, EncodingManager.A
                 }
                 else if (this.useAcceleration) {
                     double estDist = way.getTag(KEY_ESTIMATED_DISTANCE, Double.MAX_VALUE);
-                    speed = Math.max(adjustSpeedForAcceleration(estDist, speed), speedFactor);
+                    speed = adjustSpeedForAcceleration(estDist, speed);
                 }
             }
 
@@ -291,6 +296,21 @@ else if (this.useAcceleration) {
         return edgeFlags;
     }
 
+    // Override this method in order to set minimum speed rather than disabling access
+    @Override
+    protected void setSpeed(boolean reverse, IntsRef edgeFlags, double speed) {
+        if (speed >= 0.0D && !Double.isNaN(speed)) {
+            if (speed < minPossibleSpeed)
+                speed = minPossibleSpeed;
+            else if (speed > this.getMaxSpeed())
+                speed = this.getMaxSpeed();
+
+            this.speedEncoder.setDecimal(reverse, edgeFlags, speed);
+        } else {
+            throw new IllegalArgumentException("Speed cannot be negative or NaN: " + speed + ", flags:" + BitUtil.LITTLE.toBitString(edgeFlags));
+        }
+    }
+
     private void setAccess(EncodingManager.Access access, IntsRef edgeFlags, boolean fwd, boolean bwd) {
         if (fwd)
             accessEnc.setBool(false, edgeFlags, true);
@@ -473,9 +493,6 @@ protected int getTrackGradeLevel(String grade) {
             if(interimDistance < 100) {
                 speed = speed * 0.5;
             }
-            //Don't go below 2.5 because it will be stored as 0 later
-            if(speed < 5)
-                speed = 5;
         }
 
         return speed;