Add more options, including random orientations

3 files changed, 167 insertions, 63 deletions

diff --git a/src/pattern_sim.c b/src/pattern_sim.c
index ea7ed053..5e2df13b 100644
--- a/src/pattern_sim.c
+++ b/src/pattern_sim.c
@@ -35,35 +35,84 @@ static void show_help(const char *s)
 {
 	printf("Syntax: %s\n\n", s);
 	printf("Simulate diffraction patterns from small crystals\n");
-	printf(" probed with femosecond pulses from a free electron laser\n\n");
-	printf("  -h, --help            Display this help message\n");
-	printf("  --simulation-details  Show details of the simulation\n");
+	printf(" probed with femosecond pulses from a free electron laser.\n\n");
+	printf(" -h, --help                Display this help message\n");
+	printf(" --simulation-details      Show details of the simulation\n");
+	printf(" --near-bragg              Output h,k,l,I near Bragg conditions\n");
+	printf(" -r, --random-orientation  Use a randomly generated orientation\n");
+	printf("                            (a new orientation will be used for each image)\n");
+	printf(" -n, --number=<N>          Generate N images.  Default 1\n");
 }
 
 
-static void show_details(const char *s)
+static void show_details()
 {
-	printf("%s: Simulation Details\n\n", s);
-	printf("Simulates diffraction patterns from small crystals\n");
-	printf("probed with femtosecond pulses from a free electron laser\n\n");
+	printf("This program simulates diffraction patterns from small crystals illuminated\n");
+	printf("with femtosecond X-ray pulses from a free electron laser.\n\n");
+	printf("Scattering Factors\n");
+	printf("------------------\n");
+	printf("Scattering factors\n");
+}
+
+
+static struct quaternion read_quaternion()
+{
+	do {
+
+		int r;
+		float w, x, y, z;
+		char line[1024];
+		char *rval;
+
+		printf("Please input quaternion: w x y z\n");
+		rval = fgets(line, 1023, stdin);
+		if ( rval == NULL ) return invalid_quaternion();
+		chomp(line);
+
+		r = sscanf(line, "%f %f %f %f", &w, &x, &y, &z);
+		if ( r == 4 ) {
+
+			struct quaternion quat;
+
+			quat.w = w;
+			quat.x = x;
+			quat.y = y;
+			quat.z = z;
+
+			return quat;
+
+		} else {
+			fprintf(stderr, "Invalid rotation '%s'\n", line);
+		}
+
+	} while ( 1 );
 }
 
 
 int main(int argc, char *argv[])
 {
-	int c, done;
+	int c;
 	struct image image;
 	char filename[1024];
-	int number = 1;
 	int config_simdetails = 0;
+	int config_nearbragg = 0;
+	int config_randomquat = 0;
+	int number = 1;  /* Index for the current image */
+	int n_images = 1;  /* Generate one image by default */
+	int done = 0;
 
+	/* Long options */
 	const struct option longopts[] = {
-	      {"help", 0, NULL, 'h'},
-	      {"simulation-details", 0, &config_simdetails, 1},
-	      {0, 0, NULL, 0}
+		{"help",               0, NULL,               'h'},
+		{"simulation-details", 0, &config_simdetails,  1},
+		{"near-bragg",         0, &config_nearbragg,   1},
+		{"random-orientation", 0, NULL,               'r'},
+		{"number",             1, NULL,               'n'},
+		{0, 0, NULL, 0}
 	};
 
-	while ((c = getopt_long(argc, argv, "h", longopts, NULL)) != -1) {
+	/* Short options */
+	while ((c = getopt_long(argc, argv, "hrn:", longopts, NULL)) != -1) {
 
 		switch (c) {
 		case 'h' : {
@@ -71,6 +120,16 @@ int main(int argc, char *argv[])
 			return 0;
 		}
 
+		case 'r' : {
+			config_randomquat = 1;
+			break;
+		}
+
+		case 'n' : {
+			n_images = atoi(optarg);
+			break;
+		}
+
 		case 0 : {
 			break;
 		}
@@ -83,7 +142,7 @@ int main(int argc, char *argv[])
 	}
 
 	if ( config_simdetails ) {
-		show_details(argv[0]);
+		show_details();
 		return 0;
 	}
 
@@ -102,64 +161,44 @@ int main(int argc, char *argv[])
 	/* Splurge a few useful numbers */
 	printf("Wavelength is %f nm\n", image.lambda/1.0e-9);
 
-again:
-
-	/* Read quaternion from stdin */
-	done = 0;
 	do {
 
-		int r;
-		float w, x, y, z;
-		char line[1024];
-		char *rval;
-
-		printf("Please input quaternion: w x y z\n");
-		rval = fgets(line, 1023, stdin);
-		if ( rval == NULL ) return 0;
-		chomp(line);
-
-		r = sscanf(line, "%f %f %f %f", &w, &x, &y, &z);
-		if ( r == 4 ) {
-
-			printf("Rotation is: %f %f %f %f (modulus=%f)\n",
-			        w, x, y, z, sqrtf(w*w + x*x + y*y + z*z));
-
-			image.orientation.w = w;
-			image.orientation.x = x;
-			image.orientation.y = y;
-			image.orientation.z = z;
-
-			done = 1;
-
+		/* Read quaternion from stdin */
+		if ( config_randomquat ) {
+			image.orientation = random_quaternion();
 		} else {
-			fprintf(stderr, "Invalid rotation '%s'\n", line);
+			image.orientation = read_quaternion();
 		}
 
-	} while ( !done );
+		if ( quaternion_valid(image.orientation) ) {
+			fprintf(stderr, "Orientation modulus is not zero!\n");
+			return 1;
+		}
+
+		/* Ensure no residual information */
+		image.qvecs = NULL;
+		image.sfacs = NULL;
+		image.data = NULL;
+		image.twotheta = NULL;
+		image.hdr = NULL;
 
-	/* Ensure no residual information */
-	image.qvecs = NULL;
-	image.sfacs = NULL;
-	image.data = NULL;
-	image.twotheta = NULL;
-	image.hdr = NULL;
+		get_diffraction(&image);
+		record_image(&image);
 
-	get_diffraction(&image);
-	record_image(&image);
+		snprintf(filename, 1023, "results/sim-%i.h5", number);
+		number++;
 
-	snprintf(filename, 1023, "results/sim-%i.h5", number);
-	number++;
+		/* Write the output file */
+		hdf5_write(filename, image.data, image.width, image.height);
 
-	/* Write the output file */
-	hdf5_write(filename, image.data, image.width, image.height);
+		/* Clean up */
+		free(image.data);
+		free(image.qvecs);
+		free(image.hdr);
+		free(image.sfacs);
+		free(image.twotheta);
 
-	/* Clean up */
-	free(image.data);
-	free(image.qvecs);
-	free(image.hdr);
-	free(image.sfacs);
-	free(image.twotheta);
+		if ( n_images && (number >= n_images) ) done = 1;
 
-	/* Do it all again */
-	goto again;
+	} while ( !done );
 }
diff --git a/src/utils.c b/src/utils.c
index 4f5f7da3..90720510 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -94,3 +94,53 @@ double poisson_noise(double expected)
 
 	return k - 1;
 }
+
+
+double quaternion_modulus(struct quaternion q)
+{
+	return sqrt(q.w*q.w + q.x*q.x + q.y*q.y + q.z*q.z);
+}
+
+
+struct quaternion normalise_quaternion(struct quaternion q)
+{
+	double mod;
+	struct quaternion r;
+
+	mod = quaternion_modulus(q);
+
+	r.w = q.w / mod;
+	r.x = q.x / mod;
+	r.y = q.y / mod;
+	r.z = q.z / mod;
+
+	return r;
+}
+
+
+struct quaternion random_quaternion()
+{
+	struct quaternion q;
+
+	q.w = (double)random()/RAND_MAX;
+	q.x = (double)random()/RAND_MAX;
+	q.y = (double)random()/RAND_MAX;
+	q.z = (double)random()/RAND_MAX;
+	normalise_quaternion(q);
+
+	return q;
+}
+
+
+int quaternion_valid(struct quaternion q)
+{
+	double qmod;
+
+	qmod = quaternion_modulus(q);
+
+	/* Modulus = 1 to within some tolerance?
+	 * Nasty allowance for floating-point accuracy follows... */
+	if ( (qmod > 0.999) && (qmod < 1.001) ) return 1;
+
+	return 0;
+}
diff --git a/src/utils.h b/src/utils.h
index b4b5a58e..39988ae1 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -56,6 +56,11 @@ struct quaternion
 	double z;
 };
 
+extern struct quaternion normalise_quaternion(struct quaternion q);
+extern double quaternion_modulus(struct quaternion q);
+extern struct quaternion random_quaternion(void);
+extern int quaternion_valid(struct quaternion q);
+
 
 /* --------------------------- Useful functions ----------------------------- */
 
@@ -67,6 +72,16 @@ extern void progress_bar(int val, int total, const char *text);
 extern double poisson_noise(double expected);
 
 /* Keep these ones inline, to avoid function call overhead */
+static inline struct quaternion invalid_quaternion(void)
+{
+	struct quaternion quat;
+	quat.w = 0.0;
+	quat.x = 0.0;
+	quat.y = 0.0;
+	quat.z = 0.0;
+	return quat;
+}
+
 static inline double distance(double x1, double y1, double x2, double y2)
 {
 	return sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));