modify closest_to_plane_v3 not to use point-normal form.

2 files changed, 13 insertions, 17 deletions

diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index 51b89df0e4e..4a43873f070 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -89,7 +89,7 @@ float dist_to_line_v3(const float p[3], const float l1[3], const float l2[3]);
 float closest_to_line_v3(float r[3], const float p[3], const float l1[3], const float l2[3]);
 float closest_to_line_v2(float r[2], const float p[2], const float l1[2], const float l2[2]);
 void closest_to_line_segment_v3(float r[3], const float p[3], const float l1[3], const float l2[3]);
-void closest_to_plane_v3(float r[3], const float plane_co[3], const float plane_no_unit[3], const float pt[3]);
+void closest_to_plane_v3(float close_r[3], const float plane[4], const float pt[3]);
 
 /* Set 'r' to the point in triangle (t1, t2, t3) closest to point 'p' */
 void closest_on_tri_to_point_v3(float r[3], const float p[3], const float t1[3], const float t2[3], const float t3[3]);
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index 11b50802a22..2b5b0c5d0d2 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -305,24 +305,20 @@ void closest_to_line_segment_v3(float close_r[3], const float v1[3], const float
 		copy_v3_v3(close_r, cp);
 }
 
-/* find the closest point on a plane to another point and store it in close_r
- * close_r:       return coordinate
- * plane_co:      a point on the plane
- * plane_no_unit: the plane's normal, and d is the last number in the plane equation 0 = ax + by + cz + d
- * pt:            the point that you want the nearest of
+/**
+ * Find the closest point on a plane.
+ *
+ * \param close_r  Return coordinate
+ * \param plane  The plane to test against.
+ * \param pt  The point to find the nearest of
+ *
+ * \note non-unit-length planes are supported.
  */
-
-void closest_to_plane_v3(float close_r[3], const float plane_co[3], const float plane_no_unit[3], const float pt[3])
+void closest_to_plane_v3(float close_r[3], const float plane[4], const float pt[3])
 {
-	float temp[3];
-	float dotprod;
-
-	sub_v3_v3v3(temp, pt, plane_co);
-	dotprod = dot_v3v3(temp, plane_no_unit);
-
-	close_r[0] = pt[0] - (plane_no_unit[0] * dotprod);
-	close_r[1] = pt[1] - (plane_no_unit[1] * dotprod);
-	close_r[2] = pt[2] - (plane_no_unit[2] * dotprod);
+	const float length = len_squared_v3(plane);
+	const float side = plane_point_side_v3(plane, pt);
+	madd_v3_v3v3fl(close_r, pt, plane, -side / length);
 }
 
 /* signed distance from the point to the plane in 3D */