X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fgeometry%2Ftransformedshape.h;h=58e571a9db389a058cdb8ab3de1343b4ee87cb3e;hb=09cc3a8648dd20e9a07d669b353c4a120b67c1c4;hp=9a98f3139d85ef56edcd3fcdb1d8ab47116b6fee;hpb=6ff13022b53830d35283905d562c2ef3af198cc1;p=libs%2Fmath.git

diff --git a/source/geometry/transformedshape.h b/source/geometry/transformedshape.h
index 9a98f31..58e571a 100644
--- a/source/geometry/transformedshape.h
+++ b/source/geometry/transformedshape.h
@@ -2,18 +2,23 @@
 #define MSP_GEOMETRY_TRANSFORMEDSHAPE_H_
 
 #include "affinetransformation.h"
+#include "boundingbox.h"
 #include "ray.h"
 #include "shape.h"
 
 namespace Msp {
 namespace Geometry {
 
+/**
+A shape modified by an affine transformation.
+*/
 template<typename T, unsigned D>
-class TransformedShape
+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> &);
@@ -26,19 +31,27 @@ public:
 	const Shape<T, D> &get_shape() const { return *shape; }
 	const AffineTransformation<T, D> &get_transformation() const { return transformation; }
 
-	virtual bool check_intersection(const Ray<T, D> &) const;
+	virtual BoundingBox<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 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):
+inline TransformedShape<T, D>::TransformedShape(const TransformedShape<T, D> &other):
 	shape(other.shape->clone()),
-	transformation(other.transformation)
+	transformation(other.transformation),
+	inverse_trans(other.inverse_trans)
 { }
 
 template<typename T, unsigned D>
@@ -46,7 +59,8 @@ inline TransformedShape<T, D> &TransformedShape<T, D>::operator=(const Transform
 {
 	delete shape;
 	shape = other.shape->clone();
-	transformation = other.transformation();
+	transformation = other.transformation;
+	inverse_trans = other.inverse_trans;
 }
 
 template<typename T, unsigned D>
@@ -62,13 +76,62 @@ inline TransformedShape<T, D> *TransformedShape<T, D>::clone() const
 }
 
 template<typename T, unsigned D>
-inline bool TransformedShape<T, D>::check_intersection(const Ray<T, D> &ray) const
+inline BoundingBox<T, D> TransformedShape<T, D>::get_axis_aligned_bounding_box() const
+{
+	BoundingBox<T, D> inner_bbox = shape->get_axis_aligned_bounding_box();
+
+	LinAl::Vector<T, D> min_pt;
+	LinAl::Vector<T, D> max_pt;
+	for(unsigned i=0; i<(1<<D); ++i)
+	{
+		LinAl::Vector<T, D> point;
+		for(unsigned j=0; j<D; ++j)
+			point[j] = ((i>>j)&1 ? inner_bbox.get_maximum_coordinate(j) : inner_bbox.get_minimum_coordinate(j));
+
+		point = transformation.transform(point);
+
+		for(unsigned j=0; j<D; ++j)
+		{
+			min_pt[j] = std::min(min_pt[j], point[j]);
+			max_pt[j] = std::max(min_pt[j], point[j]);
+		}
+	}
+
+	return BoundingBox<T, D>(min_pt, max_pt);
+}
+
+template<typename T, unsigned D>
+inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) 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);
+	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 unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
+{
+	Ray<T, D> local_ray = make_local_ray(ray);
+
+	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_linear(points[i].normal);
+			points[i].distance = inner_product(points[i].position-ray.get_start(), ray.get_direction());
+		}
+	}
+	return count;
 }
 
 } // namespace Geometry