R/internal.R

In tessellation: Delaunay and Voronoï Tessellations

#' Objects imported from other packages
#' @description These objects are imported from other packages.
#'   Follow the links to their documentation:
#'   \code{\link[hash:values]{values}},
#'   \code{\link[hash:keys]{keys}}.
#' @importFrom hash values keys
#' @export values keys
#' @name tessellation-imports
#' @aliases values keys
#' @docType import
NULL


uniqueWith <- function(v, f){
  size <- length(v)
  for(i in seq_len(size-1L)){
    j <- i + 1L
    while(j <= size){
      if(f(v[[i]], v[[j]])){
        v <- v[-j]
        size <- size - 1L
      }else{
        j <- j + 1L
      }
    }
  }
  v[1L:size]
}


sameSegments <- function(seg1ids, seg2ids){
  ((seg1ids[[1L]] == seg2ids[[1L]]) && (seg1ids[[2L]] == seg2ids[[2L]])) ||
    ((seg1ids[[1L]] == seg2ids[[2L]]) && (seg1ids[[2L]] == seg2ids[[1L]]))
}


isBoolean <- function(x){
  is.atomic(x) && is.logical(x) && length(x) == 1L && !is.na(x)
}


crossProduct <- function(v, w){
  c(
    v[2L] * w[3L] - v[3L] * w[2L],
    v[3L] * w[1L] - v[1L] * w[3L],
    v[1L] * w[2L] - v[2L] * w[1L]
  )
}

triangleArea <- function(A, B, C){
  sqrt(c(crossprod(crossProduct(B-A, C-A)))) / 2
}