R/fct_s2_preview_img.R

In pobsteta/shinyCNES: An Amazing Shiny App

#' s2_preview_img
#'
#' @param path_data
#'
#' @return
#' @export
#'
s2_preview_img <- function(path_data = "~", 
                           project_name, 
                           collection = "Sentinel2_L2A_THEIA", 
                           tile = NULL,
                           progress_bar = TRUE) {
  collection <- ifelse(collection == "l3a", "Sentinel2_L3A_THEIA", "Sentinel2_L2A_THEIA")
  if (nchar(tile) > 1) {
    # on optimise avec le nombre de coeur du PC
    gdalcubes::gdalcubes_set_threads(parallel::detectCores() - 1)
    # On recherche les fichiers à importer dans le cube
    files <- list.files(file.path(path_data, "data"),
                        recursive = TRUE,
                        full.names = TRUE,
                        pattern = ".zip"
    )
    # on cherche le fichier tile
    files_list <- files[basename(tools::file_path_sans_ext(files)) %in% tile]
    # On cree la collection des images, on la sauvegarde
    img_col <- gdalcubes::create_image_collection(files_list,
                                       collection,
                                       unroll_archives = TRUE
    )

    # Creation de la vue jour EPSG 2154
    # vue jour a 100m de resolution
    vued <- gdalcubes::cube_view(
      srs = "EPSG:2154",
      extent = img_col,
      nx = 250, # nombre de pixel en x
      ny = 250, # nombre de pixel en y
      dt = "P1D", # time a 1 jour selon norme ISO8601
      keep.asp = TRUE
    )
    
    if (progress_bar) {
      i18n <- Translator$new(translation_json_path = "./inst/translations/translation.json")
      i18n$set_translation_language("fr")
      # Add a progress bar while importing
      withProgress(message = i18n$t("Loading preview..."), value = 0, {
        setProgress(value = 0.1)
        # calcul preview at 100m de resolution
        s_img_preview <- tryCatch(gdalcubes::raster_cube(img_col, vued) %>%
                                    gdalcubes::select_bands(c("B2", "B3", "B4")) %>%
                                    plot(rgb = 3:1, axes = FALSE),
                                  error = function(e) print(i18n$t("Input cube has no band!"))
        )
        setProgress(value = 1)
      }) # end with progress
    } else {
      # calcul preview at 100m de resolution
      s_img_preview <- tryCatch(gdalcubes::raster_cube(img_col, vued) %>%
                                  gdalcubes::select_bands(c("B2", "B3", "B4")) %>%
                                  plot(rgb = 3:1, axes = FALSE),
                                error = function(e) print("Input cube has no band!")
      )
    }
  } # end if
}