X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fgeometry%2Ftransformedshape.h;h=01253680f6340a9ed277f76664b906313f8314e2;hb=adb812a194961d542dcb0abd61258cbc8723ecd9;hp=10789ed1e15bb2db2227b6d5e1fe1f12c5adfaca;hpb=93e7cf250208c36befb4b1a7337f5302c0e1da54;p=libs%2Fmath.git

diff --git a/source/geometry/transformedshape.h b/source/geometry/transformedshape.h
index 10789ed..0125368 100644
--- a/source/geometry/transformedshape.h
+++ b/source/geometry/transformedshape.h
@@ -8,12 +8,16 @@
 namespace Msp {
 namespace Geometry {
 
+/**
+A shape modified by an affine transformation.
+*/
 template<typename T, unsigned D>
 class TransformedShape: public Shape<T, D>
 {
 private:
 	Shape<T, D> *shape;
 	AffineTransformation<T, D> transformation;
+	AffineTransformation<T, D> inverse_trans;
 
 public:
 	TransformedShape(const Shape<T, D> &, const AffineTransformation<T, D> &);
@@ -27,19 +31,24 @@ public:
 	const AffineTransformation<T, D> &get_transformation() const { return transformation; }
 
 	virtual HyperBox<T, D> get_axis_aligned_bounding_box() const;
+	virtual bool contains(const LinAl::Vector<T, D> &) const;
 	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;
 };
 
 template<typename T, unsigned D>
 inline TransformedShape<T, D>::TransformedShape(const Shape<T, D> &s, const AffineTransformation<T, D> &t):
 	shape(s.clone()),
-	transformation(t)
+	transformation(t),
+	inverse_trans(invert(t))
 { }
 
 template<typename T, unsigned D>
 inline TransformedShape<T, D>::TransformedShape(const TransformedShape &other):
 	shape(other.shape->clone()),
-	transformation(other.transformation)
+	transformation(other.transformation),
+	inverse_trans(other.inverse_trans)
 { }
 
 template<typename T, unsigned D>
@@ -48,6 +57,7 @@ inline TransformedShape<T, D> &TransformedShape<T, D>::operator=(const Transform
 	delete shape;
 	shape = other.shape->clone();
 	transformation = other.transformation;
+	inverse_trans = other.inverse_trans;
 }
 
 template<typename T, unsigned D>
@@ -69,14 +79,37 @@ inline HyperBox<T, D> TransformedShape<T, D>::get_axis_aligned_bounding_box() co
 	return shape->get_axis_aligned_bounding_box();
 }
 
+template<typename T, unsigned D>
+inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) const
+{
+	return shape->contains(inverse_trans.transform(point));
+}
+
 template<typename T, unsigned D>
 inline bool TransformedShape<T, D>::check_intersection(const Ray<T, D> &ray) const
 {
-	// TODO cache the inverse transformation for performance
-	LinAl::SquareMatrix<T, D+1> inverse_trans = LinAl::invert(transformation.get_matrix());
-	Ray<T, D> trans_ray(reduce_vector(inverse_trans*augment_vector(ray.get_start(), T(1))),
-		reduce_vector(inverse_trans*augment_vector(ray.get_direction(), T(0))));
-	return shape->check_intersection(trans_ray);
+	Ray<T, D> local_ray(inverse_trans.transform(ray.get_start()),
+		inverse_trans.transform_linear(ray.get_direction()));
+	return shape->check_intersection(local_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()));
+	unsigned count = shape->get_intersections(local_ray, points, size);
+	if(points)
+	{
+		for(unsigned i=0; i<count; ++i)
+		{
+			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);
+		}
+	}
+	return count;
 }
 
 } // namespace Geometry