Add --no-sfac option for ignoring structure factors

src/diffraction.c

@@ -133,7 +133,7 @@ double water_intensity(struct rvec q, double en,
 }
 
 
-void get_diffraction(struct image *image, int na, int nb, int nc)
+void get_diffraction(struct image *image, int na, int nb, int nc, int no_sfac)
 {
 	int x, y;
 	double ax, ay, az;
@@ -158,11 +158,13 @@ void get_diffraction(struct image *image, int na, int nb, int nc)
 	       na, nb, nc, na*a/1.0e-9, nb*b/1.0e-9, nc*c/1.0e-9);
 
 	image->sfacs = malloc(image->width * image->height
-	                      * sizeof(double complex));
+		                      * sizeof(double complex));
 
-	if ( image->molecule->reflections == NULL ) {
-		get_reflections_cached(image->molecule,
-		                       ph_lambda_to_en(image->lambda));
+	if ( !no_sfac ) {
+		if ( image->molecule->reflections == NULL ) {
+			get_reflections_cached(image->molecule,
+			                       ph_lambda_to_en(image->lambda));
+		}
 	}
 
 	for ( x=0; x<image->width; x++ ) {
@@ -177,8 +179,12 @@ void get_diffraction(struct image *image, int na, int nb, int nc)
 
 		f_lattice = lattice_factor(q, ax,ay,az,bx,by,bz,cx,cy,cz,
 		                           na, nb, nc);
-		f_molecule = molecule_factor(image->molecule, q,
+		if ( no_sfac ) {
+			f_molecule = 1.0;
+		} else {
+			f_molecule = molecule_factor(image->molecule, q,
 		                             ax,ay,az,bx,by,bz,cx,cy,cz);
+		}
 
 		val = f_molecule * f_lattice;
 		image->sfacs[x + image->width*y] = val;

src/diffraction.h

@@ -19,7 +19,8 @@
 #include "image.h"
 #include "cell.h"
 
-extern void get_diffraction(struct image *image, int na, int nb, int nc);
+extern void get_diffraction(struct image *image, int na, int nb, int nc,
+                            int nosfac);
 extern double water_intensity(struct rvec q, double en,
                               double beam_r, double water_r);
 

src/indexamajig.c

@@ -259,7 +259,7 @@ int main(int argc, char *argv[])
 
 				image.data = NULL;
 
-				get_diffraction(&image, 8, 8, 8);
+				get_diffraction(&image, 8, 8, 8, 0);
 				if ( image.molecule == NULL ) {
 					ERROR("Couldn't open molecule.pdb\n");
 					return 1;

src/pattern_sim.c

@@ -156,6 +156,7 @@ int main(int argc, char *argv[])
 	int config_nowater = 0;
 	int config_nonoise = 0;
 	int config_nobloom = 0;
+	int config_nosfac = 0;
 	int number = 1;  /* Index for the current image */
 	int n_images = 1;  /* Generate one image by default */
 	int done = 0;
@@ -171,6 +172,7 @@ int main(int argc, char *argv[])
 		{"no-water",           0, &config_nowater,     1},
 		{"no-noise",           0, &config_nonoise,     1},
 		{"no-bloom",           0, &config_nobloom,     1},
+		{"no-sfac",            0, &config_nosfac,     1},
 		{0, 0, NULL, 0}
 	};
 
@@ -272,7 +274,7 @@ int main(int argc, char *argv[])
 		image.twotheta = NULL;
 		image.hdr = NULL;
 
-		get_diffraction(&image, na, nb, nc);
+		get_diffraction(&image, na, nb, nc, config_nosfac);
 		if ( image.molecule == NULL ) {
 			ERROR("Couldn't open molecule.pdb\n");
 			return 1;