gistfile1.c

typedef struct Poly
{
  int x, y, z, .. // etc values
  struct Poly* next;
} Poly;

Poly* g_sortArray[MaxBuckets];

static void addPoly(Poly* poly, int z)
{
  poly->next = 0;

  // must make sure Z is within range here otherwise it can go bad (memory trashing)

  Poly* sortPoly = &g_sortArray[z];

  if (!sortPoly)
    g_sortArray[z] = poly;
  else
    sortPoly->next = poly;
}

void updateScene()
{
  memset(g_sortArray, 0, sizeof(Poly*) * MaxBuckets);

  // rotate, etc stuff here 
  
  for (poly in polys)
     addPoly(poly, Poly_calcZ(poly));

  renderPolys();
}

void renderPolys()
{
   for (uint i = 0; i < MaxBuckets; ++i)
   {
    const Poly* poly = &g_sortArray[i];
    if (!poly)
       continue;

     while (poly)
     {
         drawPoly(poly);
         poly = poly->next;
     }
   }
}