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cell/source/IntList.h
2025-01-14 18:10:18 -06:00

90 lines
3.1 KiB
C

/*
* This code was initially authored by the Stackoverflow user dragon-energy and posted under following page:
* https://stackoverflow.com/questions/41946007/efficient-and-well-explained-implementation-of-a-quadtree-for-2d-collision-det
*
* As for the license, the author has kindly noted:
*
* "Oh and feel free to use this code I post however you want, even for commercial projects.
* I would really love it if people let me know if they find it useful, but do as you wish."
*
* And generally all Stackoverflow-posted code is by default licensed with CC BY-SA 4.0:
* https://creativecommons.org/licenses/by-sa/4.0/
*/
#ifndef INT_LIST_H
#define INT_LIST_H
#ifdef __cplusplus
#define IL_FUNC extern "C"
#else
#define IL_FUNC
#endif
typedef struct IntList IntList;
enum {il_fixed_cap = 128};
struct IntList
{
// Stores a fixed-size buffer in advance to avoid requiring
// a heap allocation until we run out of space.
int fixed[il_fixed_cap];
// Points to the buffer used by the list. Initially this will
// point to 'fixed'.
int* data;
// Stores how many integer fields each element has.
int num_fields;
// Stores the number of elements in the list.
int num;
// Stores the capacity of the array.
int cap;
// Stores an index to the free element or -1 if the free list
// is empty.
int free_element;
};
// ---------------------------------------------------------------------------------
// List Interface
// ---------------------------------------------------------------------------------
// Creates a new list of elements which each consist of integer fields.
// 'num_fields' specifies the number of integer fields each element has.
IL_FUNC void il_create(IntList* il, int num_fields);
// Destroys the specified list.
IL_FUNC void il_destroy(IntList* il);
// Returns the number of elements in the list.
IL_FUNC int il_size(const IntList* il);
// Returns the value of the specified field for the nth element.
IL_FUNC int il_get(const IntList* il, int n, int field);
// Sets the value of the specified field for the nth element.
IL_FUNC void il_set(IntList* il, int n, int field, int val);
// Clears the specified list, making it empty.
IL_FUNC void il_clear(IntList* il);
// ---------------------------------------------------------------------------------
// Stack Interface (do not mix with free list usage; use one or the other)
// ---------------------------------------------------------------------------------
// Inserts an element to the back of the list and returns an index to it.
IL_FUNC int il_push_back(IntList* il);
// Removes the element at the back of the list.
IL_FUNC void il_pop_back(IntList* il);
// ---------------------------------------------------------------------------------
// Free List Interface (do not mix with stack usage; use one or the other)
// ---------------------------------------------------------------------------------
// Inserts an element to a vacant position in the list and returns an index to it.
IL_FUNC int il_insert(IntList* il);
// Removes the nth element in the list.
IL_FUNC void il_erase(IntList* il, int n);
#endif