source/geometry/transformedshape.h

   1 #ifndef MSP_GEOMETRY_TRANSFORMEDSHAPE_H_
   2 #define MSP_GEOMETRY_TRANSFORMEDSHAPE_H_
   3
   4 #include "affinetransformation.h"
   5 #include "ray.h"
   6 #include "shape.h"
   7
   8 namespace Msp {
   9 namespace Geometry {
  10
  11 template<typename T, unsigned D>
  12 class TransformedShape: public Shape<T, D>
  13 {
  14 private:
  15         Shape<T, D> *shape;
  16         AffineTransformation<T, D> transformation;
  17         AffineTransformation<T, D> inverse_trans;
  18
  19 public:
  20         TransformedShape(const Shape<T, D> &, const AffineTransformation<T, D> &);
  21         TransformedShape(const TransformedShape &);
  22         TransformedShape &operator=(const TransformedShape &);
  23         ~TransformedShape();
  24
  25         virtual TransformedShape *clone() const;
  26
  27         const Shape<T, D> &get_shape() const { return *shape; }
  28         const AffineTransformation<T, D> &get_transformation() const { return transformation; }
  29
  30         virtual HyperBox<T, D> get_axis_aligned_bounding_box() const;
  31         virtual bool contains(const LinAl::Vector<T, D> &) const;
  32         virtual bool check_intersection(const Ray<T, D> &) const;
  33         virtual unsigned get_max_ray_intersections() const { return shape->get_max_ray_intersections(); }
  34         virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
  35 };
  36
  37 template<typename T, unsigned D>
  38 inline TransformedShape<T, D>::TransformedShape(const Shape<T, D> &s, const AffineTransformation<T, D> &t):
  39         shape(s.clone()),
  40         transformation(t),
  41         inverse_trans(invert(t))
  42 { }
  43
  44 template<typename T, unsigned D>
  45 inline TransformedShape<T, D>::TransformedShape(const TransformedShape &other):
  46         shape(other.shape->clone()),
  47         transformation(other.transformation),
  48         inverse_trans(other.inverse_trans)
  49 { }
  50
  51 template<typename T, unsigned D>
  52 inline TransformedShape<T, D> &TransformedShape<T, D>::operator=(const TransformedShape<T, D> &other)
  53 {
  54         delete shape;
  55         shape = other.shape->clone();
  56         transformation = other.transformation;
  57         inverse_trans = other.inverse_trans;
  58 }
  59
  60 template<typename T, unsigned D>
  61 inline TransformedShape<T, D>::~TransformedShape()
  62 {
  63         delete shape;
  64 }
  65
  66 template<typename T, unsigned D>
  67 inline TransformedShape<T, D> *TransformedShape<T, D>::clone() const
  68 {
  69         return new TransformedShape<T, D>(*this);
  70 }
  71
  72 template<typename T, unsigned D>
  73 inline HyperBox<T, D> TransformedShape<T, D>::get_axis_aligned_bounding_box() const
  74 {
  75         // XXX This is not correct for most shapes
  76         return shape->get_axis_aligned_bounding_box();
  77 }
  78
  79 template<typename T, unsigned D>
  80 inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) const
  81 {
  82         return shape->contains(inverse_trans.transform(point));
  83 }
  84
  85 template<typename T, unsigned D>
  86 inline bool TransformedShape<T, D>::check_intersection(const Ray<T, D> &ray) const
  87 {
  88         Ray<T, D> local_ray(inverse_trans.transform(ray.get_start()),
  89                 inverse_trans.transform_linear(ray.get_direction()));
  90         return shape->check_intersection(local_ray);
  91 }
  92
  93 template<typename T, unsigned D>
  94 inline unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
  95 {
  96         Ray<T, D> local_ray(inverse_trans.transform(ray.get_start()),
  97                 inverse_trans.transform_linear(ray.get_direction()));
  98         unsigned count = shape->get_intersections(local_ray, points, size);
  99         if(points)
 100         {
 101                 for(unsigned i=0; i<count; ++i)
 102                 {
 103                         points[i].position = transformation.transform(points[i].position);
 104                         /* XXX This is not correct for nonuniform scaling.  Inverse of the
 105                         transpose of the upper DxD part of the matrix should be used. */
 106                         points[i].normal = transformation.transform(points[i].normal);
 107                 }
 108         }
 109         return count;
 110 }
 111
 112 } // namespace Geometry
 113 } // namespace Msp
 114
 115 #endif