utility functions: BLI_findptr, BLI_rfindptr --- use for finding an item in a linked list by a pointer.

2 files changed, 40 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_listbase.h b/source/blender/blenlib/BLI_listbase.h
index abe7eacb1ac..1330a74bea3 100644
--- a/source/blender/blenlib/BLI_listbase.h
+++ b/source/blender/blenlib/BLI_listbase.h
@@ -48,11 +48,13 @@ int BLI_findstringindex(const struct ListBase *listbase, const char *id, const i
 void *BLI_findlink(const struct ListBase *listbase, int number);
 void *BLI_findstring(const struct ListBase *listbase, const char *id, const int offset);
 void *BLI_findstring_ptr(const struct ListBase *listbase, const char *id, const int offset);
+void *BLI_findptr(const struct ListBase *listbase, const void *ptr, const int offset);
 
 /* find backwards */
 void *BLI_rfindlink(const struct ListBase *listbase, int number);
 void *BLI_rfindstring(const struct ListBase *listbase, const char *id, const int offset);
 void *BLI_rfindstring_ptr(const struct ListBase *listbase, const char *id, const int offset);
+void *BLI_rfindptr(const struct ListBase *listbase, const void *ptr, const int offset);
 
 void BLI_freelistN(struct ListBase *listbase);
 void BLI_addtail(struct ListBase *listbase, void *vlink);
diff --git a/source/blender/blenlib/intern/listbase.c b/source/blender/blenlib/intern/listbase.c
index 8fe9a94b466..ad718ed8e11 100644
--- a/source/blender/blenlib/intern/listbase.c
+++ b/source/blender/blenlib/intern/listbase.c
@@ -439,6 +439,44 @@ void *BLI_rfindstring_ptr(const ListBase *listbase, const char *id, const int of
 	return NULL;
 }
 
+void *BLI_findptr(const ListBase *listbase, const void *ptr, const int offset)
+{
+	Link *link = NULL;
+	const void *ptr_iter;
+
+	if (listbase == NULL) return NULL;
+
+	for (link = listbase->first; link; link = link->next) {
+		/* exact copy of BLI_findstring(), except for this line */
+		ptr_iter = *((const char **)(((const char *)link) + offset));
+
+		if (ptr == ptr_iter) {
+			return link;
+		}
+	}
+
+	return NULL;
+}
+/* same as above but find reverse */
+void *BLI_rfindptr(const ListBase *listbase, const void *ptr, const int offset)
+{
+	Link *link = NULL;
+	const void *ptr_iter;
+
+	if (listbase == NULL) return NULL;
+
+	for (link = listbase->last; link; link = link->prev) {
+		/* exact copy of BLI_rfindstring(), except for this line */
+		ptr_iter = *((const char **)(((const char *)link) + offset));
+
+		if (ptr == ptr_iter) {
+			return link;
+		}
+	}
+
+	return NULL;
+}
+
 int BLI_findstringindex(const ListBase *listbase, const char *id, const int offset)
 {
 	Link *link = NULL;