Function CreateSplintersFromBody

Descent3/fireball.cpp:1045–1139

Creates individual face particles from the main body of an object

#define MAX_SPLINTERS_PER_OBJECT 10
// Creates individual face particles from the main body of an object
void CreateSplintersFromBody(object *obj, float explosion_mag, float lifetime) {
  ASSERT(obj->flags & OF_POLYGON_OBJECT);
  int facenums[MAX_SPLINTERS_PER_OBJECT];
  vector rot_vecs[MAX_SUBOBJECTS];
  int num_splinters = 0;
  int i, t;
  int parent_objnum = obj - Objects;
  matrix m;
  m = obj->orient;
  vm_TransposeMatrix(&m);
  poly_model *pm = &Poly_models[obj->rtype.pobj_info.model_num];
  // If submodel 0 not renderable, bail
  if (IsNonRenderableSubmodel(pm, 0))
    return;
  bsp_info *sm = &pm->submodel[0];
  if (sm->num_faces < MAX_SPLINTERS_PER_OBJECT) {
    for (i = 0; i < sm->num_faces; i++) {
      facenums[i] = i;
      num_splinters++;
    }
  } else {
    int limit = std::min(sm->num_faces, MAX_SPLINTERS_PER_OBJECT);
    for (i = 0; i < limit; i++) {
      facenums[i] = ps_rand() % sm->num_faces;
      num_splinters++;
    }
  }
  // Now, create those splinters!
  for (i = 0; i < num_splinters; i++) {
    int facenum = facenums[i];
    vector dest, center;
    int num_verts = std::min<float>(sm->faces[facenum].nverts, MAX_VERTS_PER_SPLINTER);

    vm_MakeZero(&dest);
    vm_MakeZero(&center);
    // First get the center of this particular face
    for (t = 0; t < num_verts; t++) {
      vector pnt = sm->verts[sm->faces[facenum].vertnums[t]];
      vector temp_vec;

      temp_vec = pnt * m;
      rot_vecs[t] = temp_vec;
      center += temp_vec;
    }

    center /= num_verts;
    dest = center + obj->pos;

    // Now create splinter with that faces center position
    int s_objnum = ObjCreate(OBJ_SPLINTER, pm - Poly_models, obj->roomnum, &dest, NULL);
    if (s_objnum < 0) {
      mprintf(0, "Couldn't create splinter object!\n");
      return;
    } else {
      // Fill in relevant info

      object *splinter_obj = &Objects[s_objnum];
      splinter_obj->ctype.splinter_info.subobj_num = 0;