SDL_qsort_r(3)

NAME

SDL_qsort_r - Sort an array, passing a userdata pointer to the compare function.

HEADER FILE

Defined in SDL3/SDL_stdinc.h

SYNOPSIS

#include "SDL3/SDL.h"

void SDL_qsort_r(void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata);

DESCRIPTION

For example:

typedef enum {
    sort_increasing,
    sort_decreasing,
} sort_method;
typedef struct {
    int key;
    const char *string;
} data;
int SDLCALL compare(const void *userdata, const void *a, const void *b)
{
    sort_method method = (sort_method)(uintptr_t)userdata;
    const data *A = (const data *)a;
    const data *B = (const data *)b;
    if (A->key < B->key) {
        return (method == sort_increasing) ? -1 : 1;
    } else if (B->key < A->key) {
        return (method == sort_increasing) ? 1 : -1;
    } else {
        return 0;
    }
}
data values[] = {
    { 3, "third" }, { 1, "first" }, { 2, "second" }
};
SDL_qsort_r(values, SDL_arraysize(values), sizeof(values[0]), compare, (const void *)(uintptr_t)sort_increasing);

FUNCTION PARAMETERS

base: a pointer to the start of the array.

nmemb: the number of elements in the array.

size: the size of the elements in the array.

compare: a function used to compare elements in the array.

userdata: a pointer to pass to the compare function.

THREAD SAFETY

It is safe to call this function from any thread.

AVAILABILITY

This function is available since SDL 3.2.0.