Add ld_point_distance().

2 files changed, 23 insertions, 0 deletions

diff --git a/src/ld-types.c b/src/ld-types.c
index 512bcef..5bed9dc 100644
--- a/src/ld-types.c
+++ b/src/ld-types.c
@@ -8,6 +8,8 @@
  *
  */
 
+#include <math.h>
+
 #include <gtk/gtk.h>
 
 #include "config.h"
@@ -71,6 +73,26 @@ DEFINE_BOXED_TRIVIAL_COPY (LdPoint, ld_point)
 DEFINE_BOXED_TRIVIAL_FREE (LdPoint, ld_point)
 
 /**
+ * ld_point_distance:
+ * @self: An #LdPoint structure.
+ * @x: The X coordinate of the second point.
+ * @y: The Y coordinate of the second point.
+ *
+ * Compute the distance between two points.
+ */
+gdouble
+ld_point_distance (LdPoint *self, gdouble x, gdouble y)
+{
+	gdouble dx, dy;
+
+	g_return_val_if_fail (self != NULL, -1);
+
+	dx = self->x - x;
+	dy = self->y - y;
+	return sqrt (dx * dx + dy * dy);
+}
+
+/**
  * ld_point_array_new:
  * @num_points: The number of points the array can store.
  *
diff --git a/src/ld-types.h b/src/ld-types.h
index 6837f74..61a1a7d 100644
--- a/src/ld-types.h
+++ b/src/ld-types.h
@@ -48,6 +48,7 @@ GType ld_point_get_type (void) G_GNUC_CONST;
 
 LdPoint *ld_point_copy (const LdPoint *self);
 void ld_point_free (LdPoint *self);
+gdouble ld_point_distance (LdPoint *self, gdouble x, gdouble y);
 
 
 /**