R/remove_node_duplicates.R

In raybevel: Generates Polygon Straight Skeletons and 3D Bevels

#' Remove Node Duplicates
#'
#' @description Replace dup
#'
#' @param ss
#'
#' @keywords internal
remove_node_duplicates = function(ss) {
  ss$nodes = ss$nodes[!duplicated(ss$nodes),]
  #Calculate unique nodes (position/time)
  row_hashes = apply(ss$nodes[,c(-1,-4)], 1, digest::digest)
  unique_row_hashes = unique(row_hashes)
  id_val = rep(0, length(unique_row_hashes))
  replace_node_list = list()

  #Find first row index that matches row hash
  for(i in seq_len(length(unique_row_hashes))) {
    tmp_id_val = which(unique_row_hashes[i] == row_hashes)
    id_val[i] = tmp_id_val[1]
    replace_node_list[[i]] = tmp_id_val[-1]
  }
  #Copy original skeleton
  new_ss = ss

  #Look through all new id values and replace links references to new IDs
  for(i in seq_len(length(id_val))) {
    if(length(replace_node_list[[i]]) > 0) {
      #Replace link information with de-duplicated nodes
      new_ss$links$source[ss$links$source %in% replace_node_list[[i]] ] = id_val[i]
      new_ss$links$destination[ss$links$destination %in% replace_node_list[[i]] ] = id_val[i]
    }
  }
  new_ss$links = new_ss$links[!duplicated(new_ss$links),]
  new_ss$links = new_ss$links[new_ss$links$source != new_ss$links$destination,]

  new_ss$nodes = new_ss$nodes[!new_ss$nodes$id %in% unlist(replace_node_list),]
  new_ss_inc = make_incremental_nodes(new_ss)
  return(new_ss_inc)
}