Updated Union process for Single crystal to have three random rotatio…

…ns for the powder mode instead of just one.

mcstas-comps/union/Single_crystal_process.comp

@@ -719,16 +719,18 @@ SHARE
 
     /* Functions for "reorientation", powder and PG modes */
     /* Powder, forward */
-    void randrotate_union(double *nx, double *ny, double *nz, double a, double b) {
-      double nvx, nvy, nvz;
-      rotate(nvx,nvy,nvz, *nx, *ny, *nz, a, 1, 0, 0);
-      rotate(*nx,*ny,*nz, nvx,nvy,nvz, b, 0, 1, 0);
+    void randrotate_union(double *nx, double *ny, double *nz, double a, double b, double c) {
+      double x1, y1, z1, x2, y2, z2;
+      rotate(x1, y1, z1, *nx,*ny,*nz, a, 1, 0, 0); /* <1> = rot(<n>,a) */
+      rotate(x2, y2, z2,  x1, y1, z1, b, 0, 1, 0); /* <2> = rot(<1>,b) */
+      rotate(*nx,*ny,*nz, x2, y2, z2, c, 0, 0, 1); /* <n> = rot(<2>,c) */
     }
     /* Powder, back */
-    void randderotate_union(double *nx, double *ny, double *nz, double a, double b) {
-      double nvx, nvy, nvz;
-      rotate(nvx,nvy,nvz,*nx,*ny,*nz, -b, 0, 1, 0);
-      rotate(*nx, *ny, *nz, nvx,nvy,nvz, -a, 1, 0, 0);
+    void randderotate_union(double *nx, double *ny, double *nz, double a, double b, double c) {
+      double x1, y1, z1, x2, y2, z2;
+      rotate(x1, y1, z1, *nx,*ny,*nz, -c, 0,0,1);
+      rotate(x2, y2, z2,  x1, y1, z1, -b, 0,1,0);
+      rotate(*nx,*ny,*nz, x2, y2, z2, -a, 1,0,0);
     }
     /* PG, forward */
     void PGrotate_union(double *nx, double *ny, double *nz, double a, double csx, double csy, double csz) {
@@ -760,6 +762,7 @@ struct Single_crystal_physics_storage_struct{
     double powder_setting; // 0 if powder mode is disabled, 1 if enabled. Values between approximates texture?
     double Alpha;          // random angle between 0 and 2*Pi*powder
     double Beta;           // random angle between -Pi/2 and Pi/2
+    double Gamma;           // random angle between -Pi and Pi
 
     struct hkl_info_struct_union *hkl_info_storage; // struct containing all necessary info for SC
     double pack; // packing factor
@@ -775,19 +778,19 @@ int Single_crystal_physics_my(double *my, double *k_initial, union data_transfer
 
     struct hkl_info_struct_union *hkl_info = data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->hkl_info_storage;
 
-    // Need the Powder/PG/curvature mode rotate added here
-
     // Taken from Single_crystal and changed hkl_info to a pointer.
     // The split optimization is less useful here than normally
 
     if (data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->powder_setting) {
       //orientation of crystallite is random
 	  data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Alpha = randpm1()*PI*data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->powder_setting;
 	  data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Beta = randpm1()*PI/2;
+      data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Gamma = randpm1()*PI;
 
 	  randrotate_union(&kix, &kiy, &kiz,
         data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Alpha,
-        data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Beta);
+        data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Beta,
+        data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Gamma);
     }
     if (data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->PG_setting) {
       // orientation of crystallite is random
@@ -831,8 +834,6 @@ int Single_crystal_physics_my(double *my, double *k_initial, union data_transfer
         hkl_info->coh_xsect = coh_xsect;
         hkl_info->nb_refl += hkl_info->tau_count;
         hkl_info->nb_refl_count++;
-
-
       }
 
       /* (3). Probabilities of the different possible interactions. */
@@ -925,7 +926,10 @@ int Single_crystal_physics_scattering(double *k_final, double *k_initial, double
 
     if (data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->powder_setting) {
       // orientation of crystallite is no longer random
-	  randderotate_union(&k_final[0], &k_final[1], &k_final[2], data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Alpha, data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Beta);
+	  randderotate_union(&k_final[0], &k_final[1], &k_final[2],
+                         data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Alpha,
+                         data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Beta,
+                         data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->Gamma);
     }
     if (data_transfer.pointer_to_a_Single_crystal_physics_storage_struct->PG_setting) {
       // orientation of crystallite is longer random