Iterates over all map tiles that intersect with a rectangle in GUI coordinates. More...

#include <view_map_geometry.h>

Collaboration diagram for freeciv::gui_rect_iterator:

Public Member Functions
	gui_rect_iterator (const struct tileset *t, const QRect &rect)
	Constructor. More...

bool	has_corner () const
	Checks whether the current iteration point has a corner. More...

bool	has_edge () const
	Checks whether the current iteration point has an edge. More...

bool	has_tile () const
	Checks whether the current iteration point has a non-null tile. More...

const tile_corner &	corner () const
	Retrieves the current corner. Only valid if has_corner is `true`. More...

const tile_edge &	edge () const
	Retrieves the current edge. Only valid if has_edge is `true`. More...

const ::tile *	tile () const
	Retrieves the current tile. Only valid if has_tile is `true`. More...

int	x () const
	Retrieves the x position of the current item. More...

int	y () const
	Retrieves the y position of the current item. More...

bool	next ()
	Iterates to the next item. More...

Private Attributes
bool	m_isometric

int	m_index

int	m_count

int	m_r1

int	m_r2

int	m_w

int	m_h

int	m_x0

int	m_y0

int	m_x1

int	m_y1

int	m_xi

int	m_yi

tile_corner	m_corner

tile_edge	m_edge

::tile *	m_tile = nullptr

bool	m_has_corner = false

bool	m_has_edge = false

bool	m_has_tile = false

Detailed Description

Iterates over all map tiles that intersect with a rectangle in GUI coordinates.

The order of iteration is guaranteed to satisfy the painter's algorithm. The iteration covers not only tiles but tile edges and corners.

Iteration is performed by repeatedly calling next and querying the current available items using has_corner, has_edge, or has_tile. If the item type matches your needs, you can retrieve the corner, edge, or tile using the corresponding functions.

Typical usage is as follows:

for (auto it = gui_rect_iterator(tileset, rect); it.next(); ) {
  if (it.has_tile()) {
    auto tile = it.tile();
    // Do something
  }
}

One can also retrieve the canvas position of the current item using the x and y functions.

The order of iteration depends on the map topology. The basic idea is to operate on a rectangular grid, which works pretty nicely when the topology is neither isometric nor hexagonal:

   |     |     |
t  e  t  e  t  e  t
   |     |     |
e--c--e--c--e--c--e--
   |     |     |
t  e  t  e  t  e  t
   |     |     |
e--c--e--c--e--c--e--
   |     |     |
t  e  t  e  t  e  t
   |     |     |

In the diagram above, "t" stands for tile, "e" for edge, and "c" for corner. Iteration takes place from left to right and from top to bottom, i.e. in reading order.

Things get more complicated for isometric grids, as some points on the grid don't correspond to anything and need to be skipped. They are represented with dots in the diagram below:

t . c . t . c . t
   / \     / \
. e . e . e . e .
 /     \ /     \
c . t . c . t . c
 \     / \     /
. e . e . e . e .
   \ /     \ /
t . c . t . c . t
   / \     / \
. e . e . e . e .
 /     \ /     \
c . t . c . t . c
 \     / \     /
. e . e . e . e .
   \ /     \ /
t . c . t . c . t

For hexagonal grids, some points are corners and edges at the same time:

  . --ce- .   t   . --ce- .
   /     \         /     \
  e   .   e   .   e   .   e
 /         \     /         \
- .   t   . --ce- .   t   . -
 \         /     \         /
  e   .   e   .   e   .   e
   \     /         \     /
  . --ce- .   t   . --ce- .
   /     \         /     \
  e   .   e   .   e   .   e
 /         \     /         \
- .   t   . --ce- .   t   . -
 \         /     \         /
  e   .   e   .   e   .   e
   \     /         \     /
  . --ce-  .  t   . --ce- .

t . c . t . c . t
   / \     / \
. e . e . e . e .
 /     \ /     \
|       |       |
ce. t . ce. t . ce
|       |       |
 \     / \     /
. e . e . e . e .
   \ /     \ /
    |       |
t . ce. t . ce. t
    |       |
   / \     / \
. e . e . e . e .
 /     \ /     \
|       |       |
ce. t . ce. t . ce
|       |       |
 \     / \     /
. e . e . e . e .
   \ /     \ /
t . c . t . c . t

During iteration, it may happen that some tiles are null because they are not visible to the current player. In this case, has_tile will return false.

Definition at line 19 of file view_map_geometry.h.

Constructor & Destructor Documentation

◆ gui_rect_iterator()

freeciv::gui_rect_iterator::gui_rect_iterator	(	const struct tileset *	t,
		const QRect &	rect
	)

Constructor.

Definition at line 148 of file view_map_geometry.cpp.

Member Function Documentation

◆ corner()

const tile_corner& freeciv::gui_rect_iterator::corner ( ) const

inline

Retrieves the current corner. Only valid if has_corner is true.

Definition at line 33 of file view_map_geometry.h.

◆ edge()

const tile_edge& freeciv::gui_rect_iterator::edge ( ) const

inline

Retrieves the current edge. Only valid if has_edge is true.

Definition at line 36 of file view_map_geometry.h.

◆ has_corner()

bool freeciv::gui_rect_iterator::has_corner ( ) const

inline

Checks whether the current iteration point has a corner.

Definition at line 24 of file view_map_geometry.h.

◆ has_edge()

bool freeciv::gui_rect_iterator::has_edge ( ) const

inline

Checks whether the current iteration point has an edge.

Definition at line 27 of file view_map_geometry.h.

◆ has_tile()

bool freeciv::gui_rect_iterator::has_tile ( ) const

inline

Checks whether the current iteration point has a non-null tile.

Definition at line 30 of file view_map_geometry.h.

◆ next()

bool freeciv::gui_rect_iterator::next ( )

Iterates to the next item.

Returns false once the end of the iteration has been reached.

Definition at line 183 of file view_map_geometry.cpp.

Referenced by editor_end_selection_rectangle(), show_city_descriptions(), show_tile_labels(), and update_map_canvas().

◆ tile()

const ::tile* freeciv::gui_rect_iterator::tile ( ) const

inline

Retrieves the current tile. Only valid if has_tile is true.

Definition at line 39 of file view_map_geometry.h.

◆ x()

int freeciv::gui_rect_iterator::x ( ) const

inline

Retrieves the x position of the current item.

Definition at line 42 of file view_map_geometry.h.

◆ y()

int freeciv::gui_rect_iterator::y ( ) const

inline

Retrieves the y position of the current item.

Definition at line 45 of file view_map_geometry.h.

Member Data Documentation

◆ m_corner

tile_corner freeciv::gui_rect_iterator::m_corner

private

Definition at line 56 of file view_map_geometry.h.

Referenced by corner(), and next().

◆ m_count

int freeciv::gui_rect_iterator::m_count

private

Definition at line 51 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_edge

tile_edge freeciv::gui_rect_iterator::m_edge

private

Definition at line 57 of file view_map_geometry.h.

Referenced by edge(), and next().

◆ m_h

int freeciv::gui_rect_iterator::m_h

private

Definition at line 52 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and y().

◆ m_has_corner

bool freeciv::gui_rect_iterator::m_has_corner = false

private

Definition at line 59 of file view_map_geometry.h.

Referenced by has_corner(), and next().

◆ m_has_edge

bool freeciv::gui_rect_iterator::m_has_edge = false

private

Definition at line 59 of file view_map_geometry.h.

Referenced by has_edge(), and next().

◆ m_has_tile

bool freeciv::gui_rect_iterator::m_has_tile = false

private

Definition at line 59 of file view_map_geometry.h.

Referenced by has_tile(), and next().

◆ m_index

int freeciv::gui_rect_iterator::m_index

private

Definition at line 51 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_isometric

bool freeciv::gui_rect_iterator::m_isometric

private

Definition at line 50 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_r1

int freeciv::gui_rect_iterator::m_r1

private

Definition at line 52 of file view_map_geometry.h.

Referenced by gui_rect_iterator().

◆ m_r2

int freeciv::gui_rect_iterator::m_r2

private

Definition at line 52 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), x(), and y().

◆ m_tile

::tile* freeciv::gui_rect_iterator::m_tile = nullptr

private

Definition at line 58 of file view_map_geometry.h.

Referenced by next(), and tile().

◆ m_w

int freeciv::gui_rect_iterator::m_w

private

Definition at line 52 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and x().

◆ m_x0

int freeciv::gui_rect_iterator::m_x0

private

Definition at line 53 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_x1

int freeciv::gui_rect_iterator::m_x1

private

Definition at line 53 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_xi

int freeciv::gui_rect_iterator::m_xi

private

Definition at line 54 of file view_map_geometry.h.

Referenced by next(), and x().

◆ m_y0

int freeciv::gui_rect_iterator::m_y0

private

Definition at line 53 of file view_map_geometry.h.

Referenced by gui_rect_iterator(), and next().

◆ m_y1

int freeciv::gui_rect_iterator::m_y1

private

Definition at line 53 of file view_map_geometry.h.

Referenced by gui_rect_iterator().

◆ m_yi

int freeciv::gui_rect_iterator::m_yi

private

Definition at line 54 of file view_map_geometry.h.

Referenced by next(), and y().

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ gui_rect_iterator()

Member Function Documentation

◆ corner()

◆ edge()

◆ has_corner()

◆ has_edge()

◆ has_tile()

◆ next()

◆ tile()

◆ x()

◆ y()

Member Data Documentation

◆ m_corner

◆ m_count

◆ m_edge

◆ m_h

◆ m_has_corner

◆ m_has_edge

◆ m_has_tile

◆ m_index

◆ m_isometric

◆ m_r1

◆ m_r2

◆ m_tile

◆ m_w

◆ m_x0

◆ m_x1

◆ m_xi

◆ m_y0

◆ m_y1

◆ m_yi