Function check_terrain_node

physics/findintersection.cpp:3797–4106

void DoLinearApprox(vector *collision_point, vector *collision_normal, float *hit_dist, float *hit_interval, vector *movement_dir, vector *p0, object *obj, int nv, vector **vertex_ptr_list, vector *face_normal) { vector end_pos; bool hit; *hit_interval /= 2.0f; end_pos = *p0 + ((*hit_interval + *hit_dist)* *movement_dir); float frametime = fvi_query_ptr->f

// checks for collisions within a given terrain node (fvi_sub minus the recursiveness).
// If f_check_local_nodes is set, it will look in surrounding nodes.
inline void check_terrain_node(int cur_node, bool f_check_local_nodes, bool f_check_ground) {
  vector hit_point;
  float cur_dist;
  int check_x, check_y;
  int tercheck_x, tercheck_y;
  int new_node;
  int xcounter, ycounter;
  int xstart, xend;
  int ystart, yend;
  int terxstart, terxend;
  int terystart, teryend;
  int i;
  int objnum;
  bool f_check_next_ground;
  object *this_obj;

  if (fvi_query_ptr->thisobjnum >= 0)
    this_obj = &Objects[fvi_query_ptr->thisobjnum];
  else
    this_obj = nullptr;

  // Object checks
  if ((fvi_terrain_obj_visit_list[cur_node >> 3] & (0x01 << (cur_node % 8))) == 0) {
    ASSERT(cur_node >= 0 && cur_node < TERRAIN_WIDTH * TERRAIN_DEPTH);
    ASSERT(fvi_num_cells_obj_visited < MAX_CELLS_VISITED);
    fvi_terrain_obj_visit_list[cur_node >> 3] |= 0x01 << (cur_node % 8);
    fvi_cells_obj_visited[fvi_num_cells_obj_visited] = cur_node;
    fvi_num_cells_obj_visited++;

    if (fvi_query_ptr->flags & FQ_CHECK_OBJS) {
      for (objnum = Terrain_seg[cur_node].objects; objnum != -1; objnum = Objects[objnum].next) {
        ASSERT(objnum != -1);
        if (!(Objects[objnum].flags & OF_BIG_OBJECT))
          check_hit_obj(objnum);
      }
    } else {

      if (!(fvi_query_ptr->flags & FQ_IGNORE_EXTERNAL_ROOMS))
        for (objnum = Terrain_seg[cur_node].objects; objnum != -1; objnum = Objects[objnum].next) {
          ASSERT(objnum != -1);
          if ((Objects[objnum].type == OBJ_ROOM) && !(Objects[objnum].flags & OF_BIG_OBJECT))
            check_hit_obj(objnum);
        }
    }
  }

  // Terrain node checks
  if (f_check_ground) {
    int lod_x = (cur_node % TERRAIN_WIDTH) >> 2;
    int lod_z = (cur_node / TERRAIN_WIDTH) >> 2;

    ASSERT(cur_node >= 0 && cur_node < TERRAIN_WIDTH * TERRAIN_DEPTH);
    ASSERT((fvi_terrain_visit_list[cur_node >> 3] & (0x01 << (cur_node % 8))) == 0);
    ASSERT(fvi_num_cells_visited < MAX_CELLS_VISITED);

    // Mark the current node as visited
    fvi_terrain_visit_list[cur_node >> 3] |= 0x01 << (cur_node % 8);
    fvi_cells_visited[fvi_num_cells_visited] = cur_node;