X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fgeometry%2Ftransformedshape.h;h=bf508f9b1da31be6145fd972e350481b9502d74b;hb=643aa7b2317f88463f66da11e595ebe0f6c9621d;hp=ea7281f746067c8d0c4dcb757edd1120ee0c903b;hpb=9260eee3126731c1e6b54ce3407be757d0d71716;p=libs%2Fmath.git

diff --git a/source/geometry/transformedshape.h b/source/geometry/transformedshape.h
index ea7281f..bf508f9 100644
--- a/source/geometry/transformedshape.h
+++ b/source/geometry/transformedshape.h
@@ -8,6 +8,9 @@
 namespace Msp {
 namespace Geometry {
 
+/**
+A shape modified by an affine transformation.
+*/
 template<typename T, unsigned D>
 class TransformedShape: public Shape<T, D>
 {
@@ -29,6 +32,9 @@ public:
 
 	virtual HyperBox<T, D> get_axis_aligned_bounding_box() const;
 	virtual bool contains(const LinAl::Vector<T, D> &) const;
+private:
+	Ray<T, D> make_local_ray(const Ray<T, D> &) const;
+public:
 	virtual bool check_intersection(const Ray<T, D> &) const;
 	virtual unsigned get_max_ray_intersections() const { return shape->get_max_ray_intersections(); }
 	virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
@@ -82,19 +88,25 @@ inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) c
 	return shape->contains(inverse_trans.transform(point));
 }
 
+template<typename T, unsigned D>
+inline Ray<T, D> TransformedShape<T, D>::make_local_ray(const Ray<T, D> &ray) const
+{
+	LinAl::Vector<T, D> local_dir = inverse_trans.transform_linear(ray.get_direction());
+	float distortion = local_dir.norm();
+	return Ray<T, D>(inverse_trans.transform(ray.get_start()), local_dir, ray.get_limit()*distortion);
+}
+
 template<typename T, unsigned D>
 inline bool TransformedShape<T, D>::check_intersection(const Ray<T, D> &ray) const
 {
-	Ray<T, D> local_ray(inverse_trans.transform(ray.get_start()),
-		inverse_trans.transform_linear(ray.get_direction()));
-	return shape->check_intersection(local_ray);
+	return shape->check_intersection(make_local_ray(ray));
 }
 
 template<typename T, unsigned D>
 inline unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
 {
-	Ray<T, D> local_ray(inverse_trans.transform(ray.get_start()),
-		inverse_trans.transform_linear(ray.get_direction()));
+	Ray<T, D> local_ray = make_local_ray(ray);
+
 	unsigned count = shape->get_intersections(local_ray, points, size);
 	if(points)
 	{
@@ -103,7 +115,8 @@ inline unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray,
 			points[i].position = transformation.transform(points[i].position);
 			/* XXX This is not correct for nonuniform scaling.  Inverse of the
 			transpose of the upper DxD part of the matrix should be used. */
-			points[i].normal = transformation.transform(points[i].normal);
+			points[i].normal = transformation.transform_linear(points[i].normal);
+			points[i].distance = inner_product(points[i].position-ray.get_start(), ray.get_direction());
 		}
 	}
 	return count;