BraggPrediction: Add partiality calculation

image_analysis/bragg_prediction/BraggPredictionRot.cpp

@@ -45,7 +45,10 @@ int BraggPredictionRot::Calc(const DiffractionExperiment &experiment, const Crys
     const float m3_S0 = m3 * S0;
 
     int i = 0;
-    const float max_angle_rad = settings.max_angle_deg * static_cast<float>(M_PI) / 180.f;
+
+    const float mos_angle_rad = settings.mosaicity_deg * static_cast<float>(M_PI) / 180.f;
+    const float wedge_angle_rad = settings.wedge_deg * static_cast<float>(M_PI) / 180.f;
+    const float max_angle_rad = wedge_angle_rad / 2 + mos_angle_rad;
 
     for (int h = -settings.max_hkl; h <= settings.max_hkl; h++) {
         // Precompute A* h contribution
@@ -93,11 +96,18 @@ int BraggPredictionRot::Calc(const DiffractionExperiment &experiment, const Crys
 
                     float phi = -1.0f * std::atan2(sinphi, cosphi);
 
-                    if (phi > max_angle_rad || phi < -max_angle_rad)
+                    if (phi > wedge_angle_rad || phi < -max_angle_rad)
                         continue;
 
-                    const float lorentz_reciprocal = std::fabs(m2 * (S % S0))/(S*S0);
+                    const Coord e1 = (S % S0).Normalize();
 
+                    const float zeta_abs = std::fabs(m2 * e1);
+
+                    const float lorentz_reciprocal = std::fabs(m2 * (S % S0))/(S*S0);
+                    const float c1 = std::sqrt(2.0f) * mos_angle_rad / zeta_abs;
+
+                    const float partiality = (std::erf(zeta_abs * (phi + wedge_angle_rad / 2.0f) * c1)
+                        - std::erf(zeta_abs * (phi - wedge_angle_rad / 2.0f) * c1)) / 2.0f;
                     // Inlined RecipToDector with rot1 and rot2 (rot3 = 0)
                     // Apply rotation matrix transpose
                     float S_rot_x = rot[0] * S.x + rot[1] * S.y + rot[2] * S.z;
@@ -127,7 +137,8 @@ int BraggPredictionRot::Calc(const DiffractionExperiment &experiment, const Crys
                         .rlp = lorentz_reciprocal,
                         .S_x = S.x,
                         .S_y = S.y,
-                        .S_z = S.z
+                        .S_z = S.z,
+                        .partiality = partiality
                     };
                     i++;
                 }