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eina: document quadtree 

Reviewers: cedric, ajwillia.ms

Subscribers: segfaultxavi, jpeg

Differential Revision: https://phab.enlightenment.org/D5522

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>
This commit is contained in:
Bryce Harrington 2018-01-12 11:24:59 -08:00 committed by Cedric BAIL
parent 4916973a60
commit ebdfc54def
1 changed files with 160 additions and 12 deletions
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172
src/lib/eina/eina_quadtree.h
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@ -23,31 +23,179 @@
#include "eina_inlist.h"
typedef struct _Eina_QuadTree Eina_QuadTree;
/**
* @addtogroup Eina_Data_Types_Group Data Types
*
* @{
*/
/**
* @typedef Eina_QuadTree
*
* A quadtree is a data structure where each node contains four child
* nodes. It can be used to partition 2D spaces through subdivision
* into quadrants.
*/
typedef struct _Eina_QuadTree Eina_QuadTree;
/**
* @typedef Eina_QuadTree_Item
*
* A quadtree item is a holder for (void *) data items inside a
* quadtree, that includes some state tracking for lifecycle management
* and optimization purposes.
*/
typedef struct _Eina_QuadTree_Item Eina_QuadTree_Item;
/**
* @typedef Eina_Quad_Direction
*/
typedef enum {
EINA_QUAD_LEFT,
EINA_QUAD_RIGHT,
EINA_QUAD_BOTH
} Eina_Quad_Direction;
/**
* @typedef Eina_Quad_Callback
*
* Signature for a callback routine used to determine the location of an
* object within a quadtree. These are used in sorting by determining
* where in the tree the given data @p object belongs, using @p middle
* as the division line for the two halves of the space.
*/
typedef Eina_Quad_Direction (*Eina_Quad_Callback)(const void *object, size_t middle);
EAPI Eina_QuadTree *eina_quadtree_new(size_t w, size_t h, Eina_Quad_Callback vertical, Eina_Quad_Callback horizontal);
EAPI void eina_quadtree_free(Eina_QuadTree *q);
EAPI void eina_quadtree_resize(Eina_QuadTree *q, size_t w, size_t h);
/**
* @brief Constructs a quadtree object.
*
* @param[in] w The geometric width of the quadtree.
* @param[in] h The geometric height of the quadtree.
* @param[in] vertical The callback for vertical direction determination.
* @param[in] horizontal The callback for horizontal direction determination.
* @return The newly allocated and initialized quadtree, or @c NULL on error.
*
* The vertical and horizontal callbacks are used to assist in
* determining which quadrant a given data item belongs to.
*/
EAPI Eina_QuadTree *eina_quadtree_new(size_t w, size_t h, Eina_Quad_Callback vertical, Eina_Quad_Callback horizontal);
EAPI void eina_quadtree_cycle(Eina_QuadTree *q);
EAPI void eina_quadtree_increase(Eina_QuadTree_Item *object);
/**
* @brief Destructs quadtree and its data.
*
* @param[in] q The quadtree to be freed.
*
* Frees the memory for the Eina_QuadTree object, and any memory used by
* its change tracking and garbage collection internals.
*/
EAPI void eina_quadtree_free(Eina_QuadTree *q);
/**
* @brief Changes the width and height of the quadtree.
*
* @param[in,out] q The quadtree to resize.
* @param[in] w The new geometric width for the quadtree.
* @param[in] h The new geometric height for the quadtree.
*
* Sets the width and height of the quadtree, but the actual update is
* done lazily.
*/
EAPI void eina_quadtree_resize(Eina_QuadTree *q, size_t w, size_t h);
/**
* @brief Sets the quadtree's index to 0.
*
* @param[in,out] q The quadtree to cycle.
*/
EAPI void eina_quadtree_cycle(Eina_QuadTree *q);
/**
* @brief Increases the index of the quadtree item by one.
*
* @param[in,out] object The quadtree item to increase.
*
* If necessary, records that the root is no longer sorted.
*/
EAPI void eina_quadtree_increase(Eina_QuadTree_Item *object);
/**
* @brief Inserts a data object into the quadtree.
*
* @param[in,out] q The quadtree to add @p object to.
* @param[in] object A data object to store in the quadtree.
* @return Pointer to the stored quadtree item.
*
* Creates an Eina_QuadTree_Item (or recycles one from the quadtree's
* trash) and stores the data @p object in it, then arranges to lazily
* insert the item into the quadtree (i.e. insertion is delayed until
* it needs to be used.)
*/
EAPI Eina_QuadTree_Item *eina_quadtree_add(Eina_QuadTree *q, const void *object);
EAPI Eina_Bool eina_quadtree_del(Eina_QuadTree_Item *object);
EAPI Eina_Bool eina_quadtree_change(Eina_QuadTree_Item *object);
EAPI Eina_Bool eina_quadtree_hide(Eina_QuadTree_Item *object);
EAPI Eina_Bool eina_quadtree_show(Eina_QuadTree_Item *object);
EAPI Eina_Inlist *eina_quadtree_collide(Eina_QuadTree *q, int x, int y, int w, int h);
EAPI void *eina_quadtree_object(Eina_Inlist *list);
/**
* @brief Deletes a given quadtree item from the quadtree.
*
* @param[in] object The quadtree item to be deleted.
* @return #EINA_TRUE on success, #EINA_FALSE otherwise.
*
* Moves the item to the quadtree's internal garbage heap for later
* reclamation.
*/
EAPI Eina_Bool eina_quadtree_del(Eina_QuadTree_Item *object);
/**
* @brief Marks an object within the quadtree as needing changed.
*
* @param[in,out] object The object that has changed.
* @return #EINA_TRUE if change successfully noted, or #EINA_FALSE otherwise.
*/
EAPI Eina_Bool eina_quadtree_change(Eina_QuadTree_Item *object);
/**
* @brief Sets @p object invisible.
*
* @param[in,out] object The item within the quadtree to hide.
* @return #EINA_TRUE if @p object was successfully hidden, or
* #EINA_FALSE if it wasn't in the quadtree.
*/
EAPI Eina_Bool eina_quadtree_hide(Eina_QuadTree_Item *object);
/**
* @brief Sets @p object to visible.
*
* @param[in,out] object The item within the quadtree to show.
* @return #EINA_TRUE if @p object was successfully shown, or
* #EINA_FALSE if it wasn't in the quadtree.
*/
EAPI Eina_Bool eina_quadtree_show(Eina_QuadTree_Item *object);
/**
* @brief Retrieves items in quadtree inside the target geometry.
*
* @param[in,out] q The quadtree to recompute.
* @param[in] x New target X coordinate.
* @param[in] y New target Y coordinate.
* @param[in] w New target width.
* @param[in] h New target height.
* @return The list of collided items or @c NULL on error.
*
* Forces a rebuild and resort of the quadtree if needed due to pending
* changes, then performs a collision detection to find items whose
* geometry is contained within or intersects the given target geometry.
*/
EAPI Eina_Inlist *eina_quadtree_collide(Eina_QuadTree *q, int x, int y, int w, int h);
/**
* @brief Retrieves the quadtree item's data for the given inline list.
*
* @param[in] list The inline list item to lookup
* @return The contained data object in the Eina_QuadTree_Item, or @c
* NULL if none could be found.
*/
EAPI void *eina_quadtree_object(Eina_Inlist *list);
/**
* @}
*/
#endif