我读了一篇关于为我的一个项目创建球体的文章，可以找到here，并决定尝试将其移植到c语言，我正在使用的语言。我选择了二十面体方法，你从一个二十面体开始，然后从那里细分。问题是，我得到了seg故障，但它发生时，我试图细分它。但是如果我保持原样，不尝试细分，代码编译良好，没有错误。

#include <stdio.h>
#include <stdbool.h>
#include <math.h>
#include <stdint.h>
struct Point
{
    double x;
    double y;
    double z;
};
struct Triangle
{
    int v1;
    int v2;
    int v3;
};
// normalizes a vertex and then adds it to an array
int add_vertex(struct Point verts[], struct Point point)
{
    double length = (point.x * point.x) + (point.y * point.y) + (point.z * point.z);
    int index = 0;
    
    verts[index].x = point.x / length;
    verts[index].y = point.y / length;
    verts[index].z = point.z / length;
    
    return index++;
}
// gets the middle of a triangle face but checks to make sure that no duplicate vertices are created
int get_middle_point(int p1, int p2, struct Triangle inds[], struct Point verts[], int cache[])
{
    // check to see if the middle point is already calculated
    uint64_t key = (p1 < p2) ? (p1, p2) : (p2, p1);
    if (cache[key] != 0)
    {
        return cache[key];
    }
    // it isn't so calculate it
    struct Point point1 = verts[p1];
    struct Point point2 = verts[p2];
    struct Point middle;
    middle.x = (point1.x + point2.x) / 2.0;
    middle.y = (point1.y + point2.y) / 2.0;
    middle.z = (point1.z + point2.z) / 2.0;
    // add middle vertex to unit sphere
    int i = add_vertex(verts, middle);
    return i;
}
// creates icosphere by subdividing icosahedron
void create_icosphere(int recursion_level, struct Point verts[], struct Triangle inds[])
{
    // cache middle points
    int middle_point_cache[1000];
    // golden ratio
    float t = 1 + sqrt(5) * 0.5;
    // icosahedron cartisean coordinates from wikipedia
    add_vertex(verts, (struct Point){-1, t, 0});
    add_vertex(verts, (struct Point){1, t, 0});
    add_vertex(verts, (struct Point){-1, -t, 0});
    add_vertex(verts, (struct Point){1, -t, 0});
    add_vertex(verts, (struct Point){0, -1, t});
    add_vertex(verts, (struct Point){0, 1, t});
    add_vertex(verts, (struct Point){0, -1, -t});
    add_vertex(verts, (struct Point){0, 1, -t});
    add_vertex(verts, (struct Point){t, 0, -1});
    add_vertex(verts, (struct Point){t, 0, 1});
    add_vertex(verts, (struct Point){-t, 0, -1});
    add_vertex(verts, (struct Point){-t, 0, 1});
    // icosahedron indices
    // 5 faces around point 0
    inds[0] = (struct Triangle){0, 11, 5};
    inds[1] = (struct Triangle){0, 5, 1};
    inds[2] = (struct Triangle){0, 1, 7};
    inds[3] = (struct Triangle){0, 7, 10};
    inds[4] = (struct Triangle){0, 10, 11};
    // 5 adjacent faces
    inds[5] = (struct Triangle){1, 5, 9};
    inds[6] = (struct Triangle){5, 11, 4};
    inds[7] = (struct Triangle){11, 10, 2};
    inds[8] = (struct Triangle){10, 7, 6};
    inds[9] = (struct Triangle){7, 1, 8};
    // 5 faces around point 3
    inds[10] = (struct Triangle){3, 9, 4};
    inds[11] = (struct Triangle){3, 4, 2};
    inds[12] = (struct Triangle){3, 2, 6};
    inds[13] = (struct Triangle){3, 6, 8};
    inds[14] = (struct Triangle){3, 8, 9};
    // 5 adjacent faces
    inds[15] = (struct Triangle){4, 9, 5};
    inds[16] = (struct Triangle){2, 4, 11};
    inds[17] = (struct Triangle){6, 2, 10};
    inds[18] = (struct Triangle){8, 6, 7};
    inds[19] = (struct Triangle){9, 8, 1};
    // subdivide icosahedron
    for (int i = 0; i < recursion_level; i++)
    {
        // create new array for newly created triangle faces
        struct Triangle faces_2[1000];
        int faces_2_index = 0;
        for (int j = 0; j < 20; j++)
        {
            struct Triangle tri = inds[j];
            // get the centroid of each triangle face
            int a = get_middle_point(tri.v1, tri.v2, faces_2, verts, middle_point_cache);
            int b = get_middle_point(tri.v2, tri.v3, faces_2, verts, middle_point_cache);
            int c = get_middle_point(tri.v3, tri.v1, faces_2, verts, middle_point_cache);
            // add new faces to new faces array
            faces_2[faces_2_index++] = (struct Triangle){tri.v1, a, c};
            faces_2[faces_2_index++] = (struct Triangle){tri.v2, b, a};
            faces_2[faces_2_index++] = (struct Triangle){tri.v3, c, b};
            faces_2[faces_2_index++] = (struct Triangle){tri.v1, tri.v2, tri.v3};
        }
        // copy over contents from new array to indices
        for (int j = 0; j < faces_2_index; j++)
        {
            inds[j] = faces_2[j];
        }
    }
}
int main()
{
    // example usage. works with a subdivision level of 0 but anything higher causes a seg fault
    struct Point vertices[1000];
    struct Triangle indices[1000];
    create_icosphere(2, vertices, indices);
    printf("No errors\n");
    return 0;
}

我将问题缩小到细分循环或get_middle_point函数（在细分循环中调用）。但我不知道为什么会有错误，甚至如何解决它们。这是我的编译器目前针对细分循环内的seg错误error in nested subdivide loop所指向的位置。