krmt-geo代码分析-排序

gistfile1.txt

//https://github.com/mattsta/krmt

static int sort_gp_asc(const void *a, const void *b) {
    const struct geojsonPoint *gpa = a, *gpb = b;
    /* We can't do adist - bdist because they are doubles and
     * the comparator returns an int. */
    if (gpa->dist > gpb->dist)
        return 1;
    else if (gpa->dist == gpb->dist)
        return 0;
    else
        return -1;
}

static int sort_gp_desc(const void *a, const void *b) {
    return -sort_gp_asc(a, b);
}

struct geojsonPoint *gp = zmalloc(sizeof(*gp) * result_length);
...
qsort(gp, result_length, sizeof(*gp), sort_gp_asc);
...
qsort(gp, result_length, sizeof(*gp), sort_gp_desc);