Add image_get_feature_const() and image_feature_list_copy()

2 files changed, 28 insertions, 7 deletions

diff --git a/libcrystfel/src/image.c b/libcrystfel/src/image.c
index 63050a40..29761d7c 100644
--- a/libcrystfel/src/image.c
+++ b/libcrystfel/src/image.c
@@ -111,10 +111,7 @@ static int comp(const void *a, const void *b)
 }
 
 
-/**
- * Strongest first.
- */
-ImageFeatureList *sort_peaks(ImageFeatureList *flist)
+ImageFeatureList *image_feature_list_copy(const ImageFeatureList *flist)
 {
 	ImageFeatureList *n;
 	int nf, i;
@@ -132,15 +129,25 @@ ImageFeatureList *sort_peaks(ImageFeatureList *flist)
 
 	nf = 0;
 	for ( i=0; i<flist->n_features; i++ ) {
-		struct imagefeature *f;
-		f = image_get_feature(flist, i);
+		const struct imagefeature *f;
+		f = image_get_feature_const(flist, i);
 		if ( f == NULL ) continue;
 		n->features[nf++] = flist->features[i];
 	}
 	n->n_features = nf;
 
-	qsort(n->features, nf, sizeof(struct imagefeature), comp);
+	return n;
+}
 
+
+/**
+ * Strongest first.
+ */
+ImageFeatureList *sort_peaks(ImageFeatureList *flist)
+{
+	ImageFeatureList *n = image_feature_list_copy(flist);
+	qsort(n->features, image_feature_count(n),
+	      sizeof(struct imagefeature), comp);
 	return n;
 }
 
@@ -238,6 +245,17 @@ int image_feature_count(ImageFeatureList *flist)
 }
 
 
+const struct imagefeature *image_get_feature_const(const ImageFeatureList *flist,
+                                                   int idx)
+{
+	/* Sanity check */
+	if ( flist == NULL ) return NULL;
+	if ( idx >= flist->n_features ) return NULL;
+
+	return &flist->features[idx];
+}
+
+
 struct imagefeature *image_get_feature(ImageFeatureList *flist, int idx)
 {
 	/* Sanity check */
diff --git a/libcrystfel/src/image.h b/libcrystfel/src/image.h
index a7d7165f..fd85337c 100644
--- a/libcrystfel/src/image.h
+++ b/libcrystfel/src/image.h
@@ -222,7 +222,10 @@ extern Reflection *image_reflection_closest(RefList *rlist,
 
 extern int image_feature_count(ImageFeatureList *flist);
 extern struct imagefeature *image_get_feature(ImageFeatureList *flist, int idx);
+extern const struct imagefeature *image_get_feature_const(const ImageFeatureList *flist,
+                                                          int idx);
 extern ImageFeatureList *sort_peaks(ImageFeatureList *flist);
+extern ImageFeatureList *image_feature_list_copy(const ImageFeatureList *flist);
 
 extern void image_add_crystal(struct image *image, Crystal *cryst);
 extern int remove_flagged_crystals(struct image *image);