comments

Elements/src/Geometry/Line.cs

@@ -1224,23 +1224,16 @@ public Line Projected(Plane plane)
         }
 
         /// <summary>
-        /// Projects current line orthogonally onto another line
+        /// Projects current line onto another line
         /// </summary>
         /// <param name="line">Line to project on</param>
         /// <returns>New line on a line</returns>
         public Line Projected(Line line)
         {
             var lineDirection = line.Direction();
 
-            Vector3 ProjectPoint(Vector3 point, Vector3 lineStart)
-            {
-                var toPoint = point - lineStart;
-                var projectionLength = toPoint.Dot(lineDirection);
-                return lineStart + lineDirection.Scale(projectionLength);
-            }
-
-            var newLineStart = ProjectPoint(Start, line.Start);
-            var newLineEnd = ProjectPoint(End, line.Start);
+            var newLineStart = Start.Project(line.Start, lineDirection);
+            var newLineEnd = End.Project(line.End, lineDirection);
 
             return new Line(newLineStart, newLineEnd);
         }

Elements/src/Geometry/Vector3.cs

@@ -405,10 +405,33 @@ public double DistanceTo(Ray ray)
             {
                 return double.PositiveInfinity;
             }
-            var closestPointOnRay = ray.Origin + t * ray.Direction;
+            var closestPointOnRay = Project(ray);
             return closestPointOnRay.DistanceTo(this);
         }
 
+        /// <summary>
+        /// Project a point onto a ray.
+        /// The ray is treated as being infinitely long.
+        /// </summary>
+        /// <param name="ray">The target ray.</param>
+        public Vector3 Project(Ray ray)
+        {
+            var toPoint = this - ray.Origin;
+            var projectionLength = toPoint.Dot(ray.Direction);
+            return ray.Origin + ray.Direction.Scale(projectionLength);
+        }
+
+        /// <summary>
+        /// Project a point onto a constructed ray.
+        /// The ray is treated as being infinitely long.
+        /// </summary>
+        /// <param name="origin">The origin of the line.</param>
+        /// <param name="direction">The direction of the line.</param>
+        public Vector3 Project(Vector3 origin, Vector3 direction)
+        {
+            return Project(new Ray(origin, direction));
+        }
+
         internal double ProjectedParameterOn(Ray ray)
         {
             return ray.Direction.Dot(this - ray.Origin) / ray.Direction.Length(); // t will be [0,1]