Function check_vector_to_object

physics/findintersection.cpp:1747–1808

determine if a vector intersects with an object if no intersects, returns 0, else fills in intp and returns dist

// determine if a vector intersects with an object
// if no intersects, returns 0, else fills in intp and returns dist
int check_vector_to_object(vector *intp, float *col_dist, vector *p0, vector *p1, float rad, object *still_obj,
                           object *fvi_obj) {
  float still_size;
  vector still_pos = still_obj->pos;
  float total_size;

  int fvi_objnum = fvi_query_ptr->thisobjnum;

  if ((still_obj->flags & OF_POLYGON_OBJECT) && still_obj->type != OBJ_POWERUP && still_obj->type != OBJ_WEAPON &&
      still_obj->type != OBJ_DEBRIS && still_obj->type != OBJ_ROOM && still_obj->type != OBJ_PLAYER) {
    still_size = Poly_models[still_obj->rtype.pobj_info.model_num].anim_size;
    still_pos += still_obj->anim_sphere_offset;
  } else {
    still_size = still_obj->size;
  }

  // chrishack -- why?
  //	if (obj->type == OBJ_ROBOT && Robot_info[obj->id].attack_type)
  //		size = (size*3)/4;
  // if obj is player, and bumping into other player or a weapon of another coop player, reduce radius
  //	if (obj->type == OBJ_PLAYER &&
  //		 	((otherobj->type == OBJ_PLAYER) ||
  //	 		((Game_mode&GM_MULTI_COOP) && otherobj->type == OBJ_WEAPON &&
  // otherobj->ctype.laser_info.parent_type
  //== OBJ_PLAYER))) 		size = size/2;

  // This accounts for relative position vs. relative velocity
  if (fvi_objnum != -1 && still_obj->movement_type == MT_PHYSICS && Objects[fvi_objnum].movement_type == MT_PHYSICS) {
    if (still_obj->type != OBJ_POWERUP && Objects[fvi_objnum].type != OBJ_POWERUP) {
      if ((still_pos - Objects[fvi_objnum].pos) *
              (still_obj->mtype.phys_info.velocity - Objects[fvi_objnum].mtype.phys_info.velocity) >=
          0) {
#ifndef NED_PHYSICS
#ifdef _DEBUG
        if (Physics_player_verbose) {
          if (Player_object == &Objects[fvi_objnum]) {
            mprintf(0, "FVI: Earily exit on %d\n", OBJNUM(still_obj));
          }
        }
#endif
#endif

        return 0;
      }
    }
  }

  total_size = still_size + rad;

  if (total_size <= 0.0f) {
#ifdef _DEBUG
    if (fvi_objnum >= 0)
      mprintf(0, "Get Chris: type %d and type %d are zero radius\n", still_obj->type, Objects[fvi_objnum].type);
    else
      mprintf(0, "Get Chris: A non-object tried to hit a zero radii object of type %d\n", still_obj->type);
#endif
    return 0;
  }