1 #ifndef MSP_GEOMETRY_TRANSFORMEDSHAPE_H_
2 #define MSP_GEOMETRY_TRANSFORMEDSHAPE_H_
4 #include "affinetransformation.h"
11 A shape modified by an affine transformation.
13 template<typename T, unsigned D>
14 class TransformedShape: public Shape<T, D>
18 AffineTransformation<T, D> transformation;
19 AffineTransformation<T, D> inverse_trans;
22 TransformedShape(const Shape<T, D> &, const AffineTransformation<T, D> &);
23 TransformedShape(const TransformedShape &);
24 TransformedShape &operator=(const TransformedShape &);
27 virtual TransformedShape *clone() const;
29 const Shape<T, D> &get_shape() const { return *shape; }
30 const AffineTransformation<T, D> &get_transformation() const { return transformation; }
32 virtual BoundingBox<T, D> get_axis_aligned_bounding_box() const;
33 virtual bool contains(const LinAl::Vector<T, D> &) const;
35 Ray<T, D> make_local_ray(const Ray<T, D> &) const;
37 virtual unsigned get_max_ray_intersections() const { return shape->get_max_ray_intersections(); }
38 virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
41 template<typename T, unsigned D>
42 inline TransformedShape<T, D>::TransformedShape(const Shape<T, D> &s, const AffineTransformation<T, D> &t):
45 inverse_trans(invert(t))
48 template<typename T, unsigned D>
49 inline TransformedShape<T, D>::TransformedShape(const TransformedShape<T, D> &other):
50 shape(other.shape->clone()),
51 transformation(other.transformation),
52 inverse_trans(other.inverse_trans)
55 template<typename T, unsigned D>
56 inline TransformedShape<T, D> &TransformedShape<T, D>::operator=(const TransformedShape<T, D> &other)
59 shape = other.shape->clone();
60 transformation = other.transformation;
61 inverse_trans = other.inverse_trans;
64 template<typename T, unsigned D>
65 inline TransformedShape<T, D>::~TransformedShape()
70 template<typename T, unsigned D>
71 inline TransformedShape<T, D> *TransformedShape<T, D>::clone() const
73 return new TransformedShape<T, D>(*this);
76 template<typename T, unsigned D>
77 inline BoundingBox<T, D> TransformedShape<T, D>::get_axis_aligned_bounding_box() const
79 BoundingBox<T, D> inner_bbox = shape->get_axis_aligned_bounding_box();
81 LinAl::Vector<T, D> min_pt;
82 LinAl::Vector<T, D> max_pt;
83 for(unsigned i=0; i<(1<<D); ++i)
85 LinAl::Vector<T, D> point;
86 for(unsigned j=0; j<D; ++j)
87 point[j] = ((i>>j)&1 ? inner_bbox.get_maximum_coordinate(j) : inner_bbox.get_minimum_coordinate(j));
89 point = transformation.transform(point);
91 for(unsigned j=0; j<D; ++j)
93 min_pt[j] = std::min(min_pt[j], point[j]);
94 max_pt[j] = std::max(max_pt[j], point[j]);
98 return BoundingBox<T, D>(min_pt, max_pt);
101 template<typename T, unsigned D>
102 inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) const
104 return shape->contains(inverse_trans.transform(point));
107 template<typename T, unsigned D>
108 inline Ray<T, D> TransformedShape<T, D>::make_local_ray(const Ray<T, D> &ray) const
110 LinAl::Vector<T, D> local_dir = inverse_trans.transform_linear(ray.get_direction());
111 float distortion = local_dir.norm();
112 return Ray<T, D>(inverse_trans.transform(ray.get_start()), local_dir, ray.get_limit()*distortion);
115 template<typename T, unsigned D>
116 inline unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
118 Ray<T, D> local_ray = make_local_ray(ray);
120 unsigned count = shape->get_intersections(local_ray, points, size);
123 for(unsigned i=0; i<count; ++i)
125 points[i].position = transformation.transform(points[i].position);
126 /* XXX This is not correct for nonuniform scaling. Inverse of the
127 transpose of the upper DxD part of the matrix should be used. */
128 points[i].normal = transformation.transform_linear(points[i].normal);
129 points[i].distance = inner_product(points[i].position-ray.get_start(), ray.get_direction());
135 } // namespace Geometry