fixup! core: in LoA case, add maintain curve to indication curve befo…

…re finding intersection with overlay envelope

core/envelope-sim/src/main/kotlin/fr/sncf/osrd/envelope_sim/etcs/ETCSBrakingCurves.kt

@@ -13,6 +13,8 @@ import fr.sncf.osrd.envelope_sim.*
 import fr.sncf.osrd.envelope_sim.overlays.EnvelopeDeceleration
 import kotlin.math.max
 import kotlin.math.min
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
 
 /**
  * Formulas are found in `SUBSET-026-3v400.pdf` from the file at
@@ -35,6 +37,8 @@ enum class BrakingType {
     ETCS_GUI
 }
 
+val etcsBrakingCurvesLogger: Logger = LoggerFactory.getLogger("EtcsBrakingCurves")
+
 /** Compute braking curves at every end of authority. */
 fun addBrakingCurvesAtEOAs(
     envelope: Envelope,
@@ -86,6 +90,7 @@ fun addBrakingCurvesAtEOAs(
 
         val indicationCurve =
             keepBrakingCurveUnderOverlay(Envelope.make(fullIndicationCurve), envelope, beginPos)
+                ?: continue
         assert(indicationCurve.beginPos >= beginPos && indicationCurve.endPos == targetPosition)
         assert(
             indicationCurve.beginSpeed <= maxSpeedEnvelope &&
@@ -181,7 +186,7 @@ fun addBrakingCurvesAtLOAs(
                 fullIndCurveWithMaintain,
                 envelopeWithLoaBrakingCurves,
                 beginPos
-            )
+            ) ?: continue
         assert(indicationCurve.beginPos >= beginPos && indicationCurve.endPos == targetPosition)
         assert(
             indicationCurve.beginSpeed <= maxSpeedEnvelope &&
@@ -341,35 +346,38 @@ private fun computeIndicationBrakingCurveFromRef(
 
 /**
  * Keep the part of the full braking curve which is located underneath the overlay and intersects
- * with it or with begin position. The curve should always intersect, throw otherwise.
+ * with it or with begin position. If the part has no intersection, return null.
  */
 private fun keepBrakingCurveUnderOverlay(
     fullBrakingCurve: Envelope,
     overlay: Envelope,
     beginPos: Double
-): EnvelopePart {
-    if (fullBrakingCurve.endPos <= beginPos)
-        throw IllegalArgumentException(
-            "Expected fullBrakingCurve position range to intersect with [beginPos, +infinity[."
+): EnvelopePart? {
+    if (fullBrakingCurve.endPos <= beginPos) {
+        etcsBrakingCurvesLogger.warn(
+            "The ETCS braking curve ending at ($beginPos, ${fullBrakingCurve.endSpeed}) does not intersect with the overlay envelope."
         )
+        return null
+    }
+
+    // Remove duplicate point part transitions: the last point of the previous array is the first
+    // point of the next array. Otherwise, we would be adding two following identical points with
+    // addStep, and this would throw an exception.
     val positions =
         fullBrakingCurve
             .map { it.clonePositions() }
             .reduce { mergedArray, currentArray ->
-                // Remove duplicate part transitions: the last point of the previous array is the
-                // first point of the next array.
                 mergedArray + currentArray.drop(1).toDoubleArray()
             }
     val speeds =
         fullBrakingCurve
             .map { it.cloneSpeeds() }
             .reduce { mergedArray, currentArray ->
-                // Remove duplicate part transitions: the last point of the previous array is the
-                // first point of the next array.
                 mergedArray + currentArray.drop(1).toDoubleArray()
             }
     val timeDeltas = fullBrakingCurve.flatMap { it.cloneTimes().asList() }
     val nbPoints = positions.size
+
     val partBuilder = EnvelopePartBuilder()
     partBuilder.setAttr(EnvelopeProfile.BRAKING)
     val overlayBuilder =
@@ -382,8 +390,6 @@ private fun keepBrakingCurveUnderOverlay(
     for (i in nbPoints - 2 downTo 0) {
         if (!overlayBuilder.addStep(positions[i], speeds[i], timeDeltas[i])) break
     }
-    if (partBuilder.stepCount() <= 1)
-        throw IllegalArgumentException("Intersecting envelope only has one point.")
     return partBuilder.build()
 }