Bias GPU field. Todo : pass bias to GPUSettingsGRP to set from the nominal field, like the configGRP.solenoidBzNominalGPU

Author: shahor02

GPU/GPUTracking/Base/GPUParam.cxx

@@ -115,15 +115,15 @@ void GPUParam::UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessi
   }
 }
 
-void GPUParam::UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz)
+void GPUParam::UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz, float biasX, float biasY, float biasZ)
 {
   bzkG = newSolenoidBz;
   bzCLight = bzkG * o2::gpu::gpu_common_constants::kCLight;
   polynomialField.Reset();
   if (assumeConstantBz) {
-    GPUTPCGMPolynomialFieldManager::GetPolynomialField(GPUTPCGMPolynomialFieldManager::kUniform, bzkG, polynomialField);
+    GPUTPCGMPolynomialFieldManager::GetPolynomialField(GPUTPCGMPolynomialFieldManager::kUniform, bzkG, polynomialField, biasX, biasY, biasZ);
   } else {
-    GPUTPCGMPolynomialFieldManager::GetPolynomialField(bzkG, polynomialField);
+    GPUTPCGMPolynomialFieldManager::GetPolynomialField(bzkG, polynomialField, biasX, biasY, biasZ);
   }
   qptB5Scaler = CAMath::Abs(bzkG) > 0.1f ? CAMath::Abs(bzkG) / 5.006680f : 1.f;
 }

GPU/GPUTracking/Base/GPUParam.h

@@ -75,7 +75,7 @@ struct GPUParam : public internal::GPUParam_t<GPUSettingsRec, GPUSettingsParam>
   void SetDefaults(float solenoidBz, bool assumeConstantBz = false);
   void SetDefaults(const GPUSettingsGRP* g, const GPUSettingsRec* r = nullptr, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr);
   void UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr, const GPUSettingsRecDynamic* d = nullptr);
-  void UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz = false);
+  void UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz = false, float biasX = 0.f, float biasY = 0.f, float biasZ = 0.f);
   void UpdateRun3ClusterErrors(const float* yErrorParam, const float* zErrorParam);
 #endif
 

GPU/GPUTracking/DataTypes/GPUSettings.h

@@ -51,6 +51,7 @@ class GPUSettings
 struct GPUSettingsGRP {
   // All new members must be sizeof(int32_t) resp. sizeof(float) for alignment reasons!, default value for newly added members for old data will be 0.
   float solenoidBzNominalGPU = -5.00668f; // solenoid field strength
+  float fieldOrigin[3] = {0.f, 0.f, 0.f}; // field origin in lab
   int32_t constBz = 0;                    // for test-MC events with constant Bz
   int32_t removed0 = 0;                   // Obsolete parameter, dummy value needed to support reading old dumps
   int32_t grpContinuousMaxTimeBin = -2;   // 0 for triggered events, -1 for automatic setting, -2 invalid default

GPU/GPUTracking/Merger/GPUTPCGMPolynomialFieldManager.cxx

@@ -19,7 +19,7 @@
 
 using namespace o2::gpu;
 
-int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(StoredField_t fieldType, float nominalFieldkG, GPUTPCGMPolynomialField& field)
+int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(StoredField_t fieldType, float nominalFieldkG, GPUTPCGMPolynomialField& field, float biasX, float biasY, float biasZ)
 {
   //
   // get pre-calculated polynomial field approximation of the TPC region
@@ -180,10 +180,15 @@ int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(StoredField_t fieldTy
   field.SetFieldTrd(TrdBx, TrdBy, TrdBz);
   field.SetFieldIts(ItsBx, ItsBy, ItsBz);
 
+  if (biasX!=0.f || biasY!=0.f || biasZ!=0.f) {
+    field.ShiftFieldOriginIts(biasX, biasY, biasZ);
+    field.ShiftFieldOriginTpc(biasX, biasY, biasZ);
+    field.ShiftFieldOriginTrd(biasX, biasY, biasZ);
+  }
   return 0;
 }
 
-int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(float nominalFieldkG, GPUTPCGMPolynomialField& field)
+int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(float nominalFieldkG, GPUTPCGMPolynomialField& field, float biasX, float biasY, float biasZ)
 {
   //
   // get closest pre-calculated polynomial field approximation of the TPC region  for the given field value nominalFieldkG
@@ -204,5 +209,5 @@ int32_t GPUTPCGMPolynomialFieldManager::GetPolynomialField(float nominalFieldkG,
     type = k2kG;
   }
 
-  return GetPolynomialField(type, nominalFieldkG, field);
+  return GetPolynomialField(type, nominalFieldkG, field, biasX, biasY, biasZ);
 }

GPU/GPUTracking/Merger/GPUTPCGMPolynomialFieldManager.h

@@ -40,11 +40,11 @@ class GPUTPCGMPolynomialFieldManager
 
   /* Get appropriate pre-calculated polynomial field for the given field value nominalFieldkG
    */
-  static int32_t GetPolynomialField(float nominalFieldkG, o2::gpu::GPUTPCGMPolynomialField& field);
+  static int32_t GetPolynomialField(float nominalFieldkG, o2::gpu::GPUTPCGMPolynomialField& field, float biasX=0.f, float biasY=0.f, float biasZ=0.f);
 
   /* Get pre-calculated polynomial field of type "type", scaled with respect to nominalFieldkG
    */
-  static int32_t GetPolynomialField(StoredField_t type, float nominalFieldkG, o2::gpu::GPUTPCGMPolynomialField& field);
+  static int32_t GetPolynomialField(StoredField_t type, float nominalFieldkG, o2::gpu::GPUTPCGMPolynomialField& field, float biasX=0.f, float biasY=0.f, float biasZ=0.f);
 };
 
 #endif