Function AttachPointPos

Descent3/attach.cpp:145–228

Finds the position of a attach point on an object The uvec is optional as most attaching objects don't need at complete orientation set (only an fvec)

// Finds the position of a attach point on an object
// The uvec is optional as most attaching objects don't need at complete orientation set (only an fvec)
static bool AttachPointPos(object *obj, char ap, bool f_compute_pos, vector *attach_pos, bool f_compute_fvec,
                           vector *attach_fvec, bool *f_computed_uvec = NULL, vector *attach_uvec = NULL) {
  poly_model *pm;
  vector pnt;
  vector normal;
  vector uvec;
  matrix m;
  int mn; // submodel number
  float normalized_time[MAX_SUBOBJECTS];

  pm = &Poly_models[obj->rtype.pobj_info.model_num];

  if (ap < 0 || ap >= pm->n_attach) {
    mprintf(0, "WARNING: No ap %d on object %d.\n", ap, OBJNUM(obj));
    return false;
  }

  SetNormalizedTimeObj(obj, normalized_time);
  SetModelAnglesAndPos(pm, normalized_time);

  if (f_compute_pos)
    pnt = pm->attach_slots[ap].pnt;

  if (f_compute_fvec) {
    normal = pm->attach_slots[ap].norm;
    //	mprintf(0, "Original fvec is %f long.\n", vm_GetMagnitude(&normal));
  }

  if (pm->attach_slots[ap].f_uvec && attach_uvec && f_computed_uvec) {
    *f_computed_uvec = true;
    uvec = pm->attach_slots[ap].uvec;

    //	mprintf(0, "Original uvec is %f long.\n", vm_GetMagnitude(&uvec));
  } else if (f_computed_uvec) {
    *f_computed_uvec = false;
  }

  mn = pm->attach_slots[ap].parent;

  // Instance up the tree for this gun
  while (mn != -1) {
    vector tpnt;

    vm_AnglesToMatrix(&m, pm->submodel[mn].angs.p, pm->submodel[mn].angs.h, pm->submodel[mn].angs.b);
    vm_TransposeMatrix(&m);

    if (f_compute_pos)
      tpnt = pnt * m;

    if (f_compute_fvec)
      normal = normal * m;

    if (f_computed_uvec && *f_computed_uvec) {
      uvec = uvec * m;
    }

    if (f_compute_pos)
      pnt = tpnt + pm->submodel[mn].offset + pm->submodel[mn].mod_pos;