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vgl_box_2d< Type > Class Template Reference

#include <vgl_box_2d.h>

Inheritance diagram for vgl_box_2d< Type >:

Inheritance graph
[legend]
List of all members.

Detailed Description

template<class Type>
class vgl_box_2d< Type >

Represents a cartesian 2D box.

A 2d box with sides aligned with the x and y axes. Also supports operations required of a bounding box for geometric region tests.

A box can be empty; this is what the default constructor creates, or what is left after applying the empty() method. Use the add() methods to enlarge a box, and use the contains() methods to check for inclusion of a point or an other box.

To make the convex union of two boxes, use box1.add(box2). 

                                    MaxPosition
                      O-------------O
                      |             |
                      |             |
                      |  Centroid   |
                      |      o      |
                      |             |
          Y           |             |
          |           |             |
          |           O-------------O
          |       MinPosition
          O------X
If you are using a vgl_box_2d<int> to indicate a window on an image, do not forget that your axes will be flipped. You could think of the window as follows. 
          O------X
          |       MinPosition
          |             O-------------O
          |             |             |
          Y             |             |
                        |  Centroid   |
                        |      o      |
                        |             |
                        |             |
                        |             |
                        O-------------O
                                 MaxPosition
See also:
vgl_box_3d

Definition at line 77 of file vgl_box_2d.h.

Public Types

enum  point_type { centre = 0, min_pos, max_pos }

Public Member Functions

 vgl_box_2d ()
 Default constructor (creates empty box).
 vgl_box_2d (Type const min_position[2], Type const max_position[2])
 Construct using two corner points.
 vgl_box_2d (vgl_point_2d< Type > const &min_pos, vgl_point_2d< Type > const &max_pos)
 Construct using two corner points.
 vgl_box_2d (Type xmin, Type xmax, Type ymin, Type ymax)
 Construct using ranges in x (first two args) and y (last two).
 vgl_box_2d (Type const ref_point[2], Type width, Type height, point_type)
 Construct a box sized width x height at a given reference point.
 vgl_box_2d (vgl_point_2d< Type > const &ref_point, Type width, Type height, point_type)
 Construct a box sized width x height at a given reference point.
bool operator== (vgl_box_2d< Type > const &b) const
 Equality test.
Type width () const
 Get width of this box (= x dimension).
Type height () const
 Get height of this box (= y dimension).
Type area () const
 Get "volume" (=area) of this box.
Type volume () const
 Get "volume" (=area) of this box.
Type min_x () const
 Get min x.
Type min_y () const
 Get min y.
Type max_x () const
 Get max x.
Type max_y () const
 Get max y.
vgl_point_2d< Type > centroid () const
 Get the centroid point.
Type centroid_x () const
 Get x component of centroid.
Type centroid_y () const
 Get y component of centroid.
vgl_point_2d< Type > min_point () const
 Return lower left corner of box.
vgl_point_2d< Type > max_point () const
 Return upper right corner of box.
bool is_empty () const
 Return true if this box is empty.
void add (vgl_point_2d< Type > const &p)
 Add a point to this box.
void add (vgl_box_2d< Type > const &b)
 Make the convex union of two boxes.
bool contains (vgl_point_2d< Type > const &p) const
 Return true iff the point p is inside this box.
bool contains (vgl_box_2d< Type > const &b) const
 Return true iff the corner points of b are inside this box.
bool contains (Type const &x, Type const &y) const
 Return true if (x,y) inside box, ie x_min <= x <= x_max etc.
void empty ()
 Make the box empty.
void set_min_x (Type m)
 Set left side of box (other side ordinates unchanged).
void set_min_y (Type m)
 Set bottom of box (other side ordinates unchanged).
void set_max_x (Type m)
 Set right side (other side ordinates unchanged).
void set_max_y (Type m)
 Set top (other side ordinates unchanged).
void set_centroid_x (Type cx)
 Move box so centroid lies at cx (width and height unchanged).
void set_centroid_y (Type cy)
 Move box so centroid lies at cy (width and height unchanged).
void set_width (Type width)
 Modify width, retaining centroid at current position.
void set_height (Type height)
 Modify height, retaining centroid at current position.
void expand_about_centroid (Type expand)
 Add to width and height, centroid unchanged.
void scale_about_centroid (double s)
 Scale width and height, centroid unchanged.
void scale_about_origin (double s)
 Scale width and height, keeping scaled position of origin unchanged.
void setmin_position (Type const min_position[2])
 Modify bottom left. Top right only changed if necessary to avoid empty box.
void setmax_position (Type const max_position[2])
 Modify top right. Bottom left only changed if necessary to avoid empty box.
void set_min_point (vgl_point_2d< Type > const &min_pt)
 Modify bottom left. Top right only changed if necessary to avoid empty box.
void set_max_point (vgl_point_2d< Type > const &max_pt)
 Modify top right. Bottom left only changed if necessary to avoid empty box.
void set_centroid (Type const c[2])
 Move box so centroid lies at c (width, height unchanged).
void set_centroid (vgl_point_2d< Type > const &c)
 Move box so centroid lies at c (width, height unchanged).
vcl_ostream & print (vcl_ostream &) const
 Write "<vgl_box_2d x0,y0 to x1,y1>" to stream.
vcl_ostream & write (vcl_ostream &) const
 Write "x0 y0 x1 y1(endl)" to stream.
vcl_istream & read (vcl_istream &)
 Read x0,y0,x1,y1 from stream.

Protected Attributes

Type min_pos_ [2]
Type max_pos_ [2]

Related Functions

(Note that these are not member functions.)

vcl_ostream & operator<< (vcl_ostream &s, vgl_box_2d< Type > const &p)
 Write box to stream.
vcl_istream & operator>> (vcl_istream &is, vgl_box_2d< Type > &p)
 Read box from stream.
vgl_box_2d< Type > vgl_intersection (vgl_box_2d< Type > const &a, vgl_box_2d< Type > const &b)
 Return box defining intersection between boxes a and b.
vgl_line_segment_2d< T > vgl_clip_line_to_box (vgl_line_2d< T > const &l, vgl_box_2d< T > const &b)
 clip given line to given box, and return resulting line segment.

Member Enumeration Documentation

template<class Type>
enum vgl_box_2d::point_type
 

Enumerator:
centre 
min_pos 
max_pos 

Definition at line 95 of file vgl_box_2d.h.

Constructor & Destructor Documentation

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (   ) 
 

Default constructor (creates empty box).

Definition at line 17 of file vgl_box_2d.txx.

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (  Type const   min_position[2],
Type const   max_position[2]
) 
 

Construct using two corner points.

Definition at line 24 of file vgl_box_2d.txx.

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (  vgl_point_2d< Type > const &  min_pos,
vgl_point_2d< Type > const &  max_pos
) 
 

Construct using two corner points.

Definition at line 33 of file vgl_box_2d.txx.

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (  Type  xmin,
Type  xmax,
Type  ymin,
Type  ymax
) 
 

Construct using ranges in x (first two args) and y (last two).

Definition at line 42 of file vgl_box_2d.txx.

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (  Type const   ref_point[2],
Type  width,
Type  height,
point_type 
) 
 

Construct a box sized width x height at a given reference point.

The box will either be centered at ref_point or will have ref_point as its min-position or max-position, as specified by the 4th argument.

template<class Type>
vgl_box_2d< Type >::vgl_box_2d (  vgl_point_2d< Type > const &  ref_point,
Type  width,
Type  height,
point_type 
) 
 

Construct a box sized width x height at a given reference point.

The box will either be centered at ref_point or will have ref_point as its min-position or max-position, as specified by the 4th argument.

Member Function Documentation

template<class Type>
void vgl_box_2d< Type >::add (  vgl_box_2d< Type > const &  b  ) 
 

Make the convex union of two boxes.

Do this by possibly enlarging this box so that the corner points of the given box just fall within the box. Adding an empty box does not change the current box.

Definition at line 348 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::add (  vgl_point_2d< Type > const &  p  ) 
 

Add a point to this box.

Do this by possibly enlarging the box so that the point just falls within the box. Adding a point to an empty box makes it a size zero box only containing p.

Definition at line 327 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::area (   )  const [inline]
 

Get "volume" (=area) of this box.

Definition at line 127 of file vgl_box_2d.h.

template<class Type>
vgl_point_2d< Type > vgl_box_2d< Type >::centroid (   )  const
 

Get the centroid point.

Definition at line 150 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::centroid_x (   )  const
 

Get x component of centroid.

Definition at line 110 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::centroid_y (   )  const
 

Get y component of centroid.

Definition at line 117 of file vgl_box_2d.txx.

template<class Type>
bool vgl_box_2d< Type >::contains (  Type const &  x,
Type const &  y
)  const [inline]
 

Return true if (x,y) inside box, ie x_min <= x <= x_max etc.

Definition at line 178 of file vgl_box_2d.h.

template<class Type>
bool vgl_box_2d< Type >::contains (  vgl_box_2d< Type > const &  b  )  const
 

Return true iff the corner points of b are inside this box.

Definition at line 364 of file vgl_box_2d.txx.

template<class Type>
bool vgl_box_2d< Type >::contains (  vgl_point_2d< Type > const &  p  )  const
 

Return true iff the point p is inside this box.

Definition at line 357 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::empty (   ) 
 

Make the box empty.

Definition at line 373 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::expand_about_centroid (  Type  expand  ) 
 

Add to width and height, centroid unchanged.

Will move each side by expand / 2.

Definition at line 219 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::height (   )  const
 

Get height of this box (= y dimension).

Definition at line 130 of file vgl_box_2d.txx.

template<class Type>
bool vgl_box_2d< Type >::is_empty (   )  const [inline]
 

Return true if this box is empty.

Definition at line 156 of file vgl_box_2d.h.

template<class Type>
vgl_point_2d< Type > vgl_box_2d< Type >::max_point (   )  const
 

Return upper right corner of box.

Definition at line 143 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::max_x (   )  const [inline]
 

Get max x.

Definition at line 136 of file vgl_box_2d.h.

template<class Type>
Type vgl_box_2d< Type >::max_y (   )  const [inline]
 

Get max y.

Definition at line 138 of file vgl_box_2d.h.

template<class Type>
vgl_point_2d< Type > vgl_box_2d< Type >::min_point (   )  const
 

Return lower left corner of box.

Definition at line 136 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::min_x (   )  const [inline]
 

Get min x.

Definition at line 132 of file vgl_box_2d.h.

template<class Type>
Type vgl_box_2d< Type >::min_y (   )  const [inline]
 

Get min y.

Definition at line 134 of file vgl_box_2d.h.

template<class Type>
bool vgl_box_2d< Type >::operator== (  vgl_box_2d< Type > const &  b  )  const [inline]
 

Equality test.

Definition at line 112 of file vgl_box_2d.h.

template<class Type>
vcl_ostream & vgl_box_2d< Type >::print (  vcl_ostream &   )  const
 

Write "<vgl_box_2d x0,y0 to x1,y1>" to stream.

Definition at line 285 of file vgl_box_2d.txx.

template<class Type>
vcl_istream & vgl_box_2d< Type >::read (  vcl_istream &   ) 
 

Read x0,y0,x1,y1 from stream.

Definition at line 303 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::scale_about_centroid (  double  s  ) 
 

Scale width and height, centroid unchanged.

Definition at line 228 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::scale_about_origin (  double  s  ) 
 

Scale width and height, keeping scaled position of origin unchanged.

Definition at line 238 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_centroid (  vgl_point_2d< Type > const &  c  )  [inline]
 

Move box so centroid lies at c (width, height unchanged).

Definition at line 233 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_centroid (  Type const   c[2]  )  [inline]
 

Move box so centroid lies at c (width, height unchanged).

Definition at line 231 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_centroid_x (  Type  cx  ) 
 

Move box so centroid lies at cx (width and height unchanged).

Definition at line 157 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_centroid_y (  Type  cy  ) 
 

Move box so centroid lies at cy (width and height unchanged).

Definition at line 166 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_height (  Type  height  ) 
 

Modify height, retaining centroid at current position.

For integer types, centroid might change slightly, but repeat calls to set_height will not cause centroid drift.

Definition at line 209 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_max_point (  vgl_point_2d< Type > const &  max_pt  ) 
 

Modify top right. Bottom left only changed if necessary to avoid empty box.

Definition at line 278 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_max_x (  Type  m  )  [inline]
 

Set right side (other side ordinates unchanged).

Definition at line 199 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_max_y (  Type  m  )  [inline]
 

Set top (other side ordinates unchanged).

Definition at line 201 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_min_point (  vgl_point_2d< Type > const &  min_pt  ) 
 

Modify bottom left. Top right only changed if necessary to avoid empty box.

Definition at line 271 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::set_min_x (  Type  m  )  [inline]
 

Set left side of box (other side ordinates unchanged).

Definition at line 195 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_min_y (  Type  m  )  [inline]
 

Set bottom of box (other side ordinates unchanged).

Definition at line 197 of file vgl_box_2d.h.

template<class Type>
void vgl_box_2d< Type >::set_width (  Type  width  ) 
 

Modify width, retaining centroid at current position.

For integer types, centroid might change slightly, but repeat calls to set_height will not cause centroid drift.

Definition at line 199 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::setmax_position (  Type const   max_position[2]  ) 
 

Modify top right. Bottom left only changed if necessary to avoid empty box.

Definition at line 260 of file vgl_box_2d.txx.

template<class Type>
void vgl_box_2d< Type >::setmin_position (  Type const   min_position[2]  ) 
 

Modify bottom left. Top right only changed if necessary to avoid empty box.

Definition at line 247 of file vgl_box_2d.txx.

template<class Type>
Type vgl_box_2d< Type >::volume (   )  const [inline]
 

Get "volume" (=area) of this box.

Definition at line 129 of file vgl_box_2d.h.

template<class Type>
Type vgl_box_2d< Type >::width (   )  const
 

Get width of this box (= x dimension).

Definition at line 124 of file vgl_box_2d.txx.

template<class Type>
vcl_ostream & vgl_box_2d< Type >::write (  vcl_ostream &   )  const
 

Write "x0 y0 x1 y1(endl)" to stream.

Definition at line 296 of file vgl_box_2d.txx.

Friends And Related Function Documentation

template<class Type>
vcl_ostream & operator<< (  vcl_ostream &  s,
vgl_box_2d< Type > const &  p
)  [related]
 

Write box to stream.

Definition at line 381 of file vgl_box_2d.txx.

template<class Type>
vcl_istream & operator>> (  vcl_istream &  is,
vgl_box_2d< Type > &  p
)  [related]
 

Read box from stream.

Definition at line 388 of file vgl_box_2d.txx.

template<class Type>
vgl_line_segment_2d< T > vgl_clip_line_to_box (  vgl_line_2d< T > const &  l,
vgl_box_2d< T > const &  b
)  [related]
 

clip given line to given box, and return resulting line segment.

Definition at line 52 of file vgl_clip.h.

template<class Type>
vgl_box_2d< Type > vgl_intersection (  vgl_box_2d< Type > const &  a,
vgl_box_2d< Type > const &  b
)  [related]
 

Return box defining intersection between boxes a and b.

Empty box returned if no intersection.

Definition at line 310 of file vgl_box_2d.txx.

Member Data Documentation

template<class Type>
Type vgl_box_2d< Type >::max_pos_[2] [protected]
 

Definition at line 250 of file vgl_box_2d.h.

template<class Type>
Type vgl_box_2d< Type >::min_pos_[2] [protected]
 

Definition at line 249 of file vgl_box_2d.h.

The documentation for this class was generated from the following files:
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