R/flsgen_create_landscape_structure.R

In rflsgen: Neutral Landscape Generator with Targets on Landscape Indices

# Copyright (c) 2021, Dimitri Justeau-Allaire
#
# Institut Agronomique neo-Caledonien (IAC), 98800 Noumea, New Caledonia
# AMAP, Univ Montpellier, CIRAD, CNRS, INRA, IRD, Montpellier, France
#
# This file is part of rflsgen
#
# rflsgen is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# rflsgen is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with rflsgen  If not, see <https://www.gnu.org/licenses/>.

#' Creates a predefined landscape structure that can be converted as JSON
#' Input for flsgen generate
#'
#' @description Creates a predefined landscape structure that can be converted as JSON
#' converted as JSON Input for flsgen generate.
#'
#' @details The class structures must be created prior to the call to this function
#'
#' @param nb_rows Number of rows
#' @param nb_cols Number of columns
#' @param classes list of class structures
#' @param mask_raster mask raster (path or terra::rast object)
#'
#' @import terra
#'
#' @details Either nb_rows and nb_cols, or mask_raster must be specified. The dimensions
#' of the landscape are deduced from the mask raster if it is used.
#'
#' @return A landscape structure object which can be converted to JSON for
#' flsgen generate
#'
#' @examples
#'   \dontrun{
#'     cls_1 <- flsgen_class_structure("class 1", c(10, 100, 1000))
#'     cls_2 <- flsgen_class_structure("class 2", c(20, 200, 2000))
#'     ls_struct <- flsgen_landscape_structure(200, 200, list(cls_1, cls_2))
#'   }
#'
#' @export
flsgen_create_landscape_structure <- function(nb_rows, nb_cols, classes, mask_raster=NULL) {
  if (!is.null(classes)) {
    checkmate::assert_list(classes)
    u <- unique(lapply(classes, function(c) {c$name}))
    if (length(u) != length(classes)) {
      stop("The class names are not unique")
    }
  }
  lstruct <- list(
    classes = classes
  )
  if (is.null(mask_raster)) {
    checkmate::assert_int(nb_rows, lower=1)
    checkmate::assert_int(nb_cols, lower=1)
    lstruct$nbRows <- nb_rows
    lstruct$nbCols <- nb_cols
  } else {
    if (inherits(mask_raster, "SpatRaster")) {
      s <- terra::sources(mask_raster)[[1]]
      on_disk <- all(nchar(s > 0) && all(file.exists(s)))
      if (on_disk) {
        lstruct$maskRasterPath <- s
      }
      lstruct$maskRaster <- mask_raster
    }
  }
  return(structure(lstruct, class="FlsgenLandscapeStructure"))
}