Temporary use simplified version of propagateToAlphaX

shahor02 · shahor02 · commit fe4ee685224e · 2022-11-13T13:25:45.000+01:00
diff --git a/Detectors/Base/include/DetectorsBase/Propagator.h b/Detectors/Base/include/DetectorsBase/Propagator.h
@@ -96,7 +96,7 @@ class PropagatorImpl
   }
 
   template <typename track_T>
-  GPUd() bool propagateToAlphaX(track_T& track, value_type alpha, value_type x, bool bzOnly = false, value_type maxSnp = MAX_SIN_PHI, value_type maxStep = MAX_STEP,
+  GPUd() bool propagateToAlphaX(track_T& track, value_type alpha, value_type x, bool bzOnly = false, value_type maxSnp = MAX_SIN_PHI, value_type maxStep = MAX_STEP, int minSteps = 1,
                                 MatCorrType matCorr = MatCorrType::USEMatCorrLUT, track::TrackLTIntegral* tofInfo = nullptr, int signCorr = 0) const;
 
   GPUd() bool propagateToDCA(const o2::dataformats::VertexBase& vtx, o2::track::TrackParametrizationWithError<value_type>& track, value_type bZ,
@@ -160,7 +160,7 @@ class PropagatorImpl
   PropagatorImpl(bool uninitialized = false);
   ~PropagatorImpl() = default;
 #endif
-
+  static constexpr value_type Epsilon = 0.00001; // precision of propagation to X
   template <typename T>
   GPUd() void getFieldXYZImpl(const math_utils::Point3D<T> xyz, T* bxyz) const;
 
diff --git a/Detectors/Base/src/Propagator.cxx b/Detectors/Base/src/Propagator.cxx
@@ -164,7 +164,6 @@ GPUd() bool PropagatorImpl<value_T>::PropagateToXBxByBz(TrackParCov_t& track, va
   //
   // matCorr  - material correction type, it is up to the user to make sure the pointer is attached (if LUT is requested)
   //----------------------------------------------------------------
-  const value_type Epsilon = 0.00001;
   auto dx = xToGo - track.getX();
   int dir = dx > 0.f ? 1 : -1;
   if (!signCorr) {
@@ -226,7 +225,6 @@ GPUd() bool PropagatorImpl<value_T>::PropagateToXBxByBz(TrackPar_t& track, value
   //
   // matCorr  - material correction type, it is up to the user to make sure the pointer is attached (if LUT is requested)
   //----------------------------------------------------------------
-  const value_type Epsilon = 0.00001;
   auto dx = xToGo - track.getX();
   int dir = dx > 0.f ? 1 : -1;
   if (!signCorr) {
@@ -286,7 +284,6 @@ GPUd() bool PropagatorImpl<value_T>::propagateToX(TrackParCov_t& track, value_ty
   //
   // matCorr  - material correction type, it is up to the user to make sure the pointer is attached (if LUT is requested)
   //----------------------------------------------------------------
-  const value_type Epsilon = 0.00001;
   auto dx = xToGo - track.getX();
   int dir = dx > 0.f ? 1 : -1;
   if (!signCorr) {
@@ -346,7 +343,6 @@ GPUd() bool PropagatorImpl<value_T>::propagateToX(TrackPar_t& track, value_type
   //
   // matCorr  - material correction type, it is up to the user to make sure the pointer is attached (if LUT is requested)
   //----------------------------------------------------------------
-  const value_type Epsilon = 0.00001;
   auto dx = xToGo - track.getX();
   int dir = dx > 0.f ? 1 : -1;
   if (!signCorr) {
@@ -393,24 +389,34 @@ GPUd() bool PropagatorImpl<value_T>::propagateToX(TrackPar_t& track, value_type
 //_______________________________________________________________________
 template <typename value_T>
 template <typename track_T>
-GPUd() bool PropagatorImpl<value_T>::propagateToAlphaX(track_T& track, value_type alpha, value_type x, bool bzOnly, value_type maxSnp, value_type maxStep,
+GPUd() bool PropagatorImpl<value_T>::propagateToAlphaX(track_T& track, value_type alpha, value_type x, bool bzOnly, value_type maxSnp, value_type maxStep, int minSteps,
                                                        MatCorrType matCorr, track::TrackLTIntegral* tofInfo, int signCorr) const
 {
   // propagate to alpha,X, if needed in a few steps
   auto snp = track.getSnpAt(alpha, x, getNominalBz());
   // apply safety factor 0.9 for crude rotation estimate
-  if (math_utils::detail::abs<value_type>(snp) < maxSnp * 0.9 && track.rotate(alpha) && propagateTo(track, x, bzOnly, maxSnp, maxStep, matCorr, tofInfo, signCorr)) {
-    return true;
+  if (math_utils::detail::abs<value_type>(snp) < maxSnp * 0.9 && track.rotate(alpha)) {
+    auto dx = math_utils::detail::abs<value_type>(x - track.getX());
+    if (dx < Epsilon) {
+      return true;
+    }
+    return propagateTo(track, x, bzOnly, maxSnp, math_utils::detail::min<value_type>(dx / minSteps, maxStep), matCorr, tofInfo, signCorr);
   }
+  return false;
+  /*
   // try to go in a few steps with intermediate rotations
+
+
   auto alphaTrg = alpha;
   math_utils::detail::bringToPMPi<value_type>(alphaTrg);
   auto alpCurr = track.getAlpha();
   math_utils::detail::bringToPMPi<value_type>(alpCurr);
-  auto dalp = math_utils::detail::deltaPhiSmall<value_type>(alpCurr, alphaTrg) / 2; // effective half (alpha - alphaCurr)
-  auto xtmp = (track.getX() + x) / 2;
+  int nsteps = minSteps > 2 ? minSteps : 2;
+  auto dalp = math_utils::detail::deltaPhiSmall<value_type>(alpCurr, alphaTrg) / nsteps; // effective  (alpha - alphaCurr)/nsteps
+  auto xtmp = (track.getX() + x) / nsteps;
   return track.rotate(alpCurr + dalp) && propagateTo(track, xtmp, bzOnly, maxSnp, maxStep, matCorr, tofInfo, signCorr) &&
          track.rotate(alpha) && propagateTo(track, x, bzOnly, maxSnp, maxStep, matCorr, tofInfo, signCorr);
+  */
 }
 
 //_______________________________________________________________________
@@ -730,11 +736,11 @@ template class PropagatorImpl<float>;
 template class PropagatorImpl<double>;
 #endif
 #ifndef __HIPCC__ // TODO: Fixme: must prevent HIP from compiling this, should file bug report
-template bool GPUd() PropagatorImpl<float>::propagateToAlphaX<PropagatorImpl<float>::TrackPar_t>(PropagatorImpl<float>::TrackPar_t&, float, float, bool, float, float, PropagatorImpl<float>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
-template bool GPUd() PropagatorImpl<float>::propagateToAlphaX<PropagatorImpl<float>::TrackParCov_t>(PropagatorImpl<float>::TrackParCov_t&, float, float, bool, float, float, PropagatorImpl<float>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
+template bool GPUd() PropagatorImpl<float>::propagateToAlphaX<PropagatorImpl<float>::TrackPar_t>(PropagatorImpl<float>::TrackPar_t&, float, float, bool, float, float, int, PropagatorImpl<float>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
+template bool GPUd() PropagatorImpl<float>::propagateToAlphaX<PropagatorImpl<float>::TrackParCov_t>(PropagatorImpl<float>::TrackParCov_t&, float, float, bool, float, float, int, PropagatorImpl<float>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
 #ifndef GPUCA_GPUCODE_DEVICE
-template bool PropagatorImpl<double>::propagateToAlphaX<PropagatorImpl<double>::TrackPar_t>(PropagatorImpl<double>::TrackPar_t&, double, double, bool, double, double, PropagatorImpl<double>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
-template bool PropagatorImpl<double>::propagateToAlphaX<PropagatorImpl<double>::TrackParCov_t>(PropagatorImpl<double>::TrackParCov_t&, double, double, bool, double, double, PropagatorImpl<double>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
+template bool PropagatorImpl<double>::propagateToAlphaX<PropagatorImpl<double>::TrackPar_t>(PropagatorImpl<double>::TrackPar_t&, double, double, bool, double, double, int, PropagatorImpl<double>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
+template bool PropagatorImpl<double>::propagateToAlphaX<PropagatorImpl<double>::TrackParCov_t>(PropagatorImpl<double>::TrackParCov_t&, double, double, bool, double, double, int, PropagatorImpl<double>::MatCorrType matCorr, track::TrackLTIntegral*, int) const;
 #endif
 #endif
 } // namespace o2::base
