R/rv_magick.R

In EDJNet/riskviewer: A modern implementation of the Risk Characterisation Theatre

#' Converts output to an image object in standard formats.
#'
#' @param plot A plot, typically generated with e.g. `rv_create_arena()`
#' @param quality One of either "low" (output 1024px width), "medium" (output 1512px width), or "high" (output 2048px width). Defaults to "low". 
#' @param bg Background colour.
#' @param stack Logical, defaults to FALSE. If TRUE, graphs are placed left-to-right, if FALSE top-to-bottom.
#'
#' @return
#' @export
#'
#' @examples
#' 
#' plot <- rv_create_arena(ratio = 0.7)
#' rv_img(plot, quality = "medium")
#' 
rv_img <- function(plot,
                   quality = "low", 
                   bg = "white",
                   stack = FALSE) {
  if (quality == "low") {
    graphs_img <- magick::image_graph(res = 96,
                                      pointsize = 12,
                                      width = 1251,
                                      height = 1251,
                                      bg = bg)
    if (is.element("list",class(plot))) {
      purrr::walk(.x = plot, .f = print)
    } else {
      print(plot)
    }
    invisible(dev.off())
  } else if (quality == "medium") {
    graphs_img <- magick::image_graph(res = 150,
                                      pointsize = 12,
                                      width = 1859,
                                      height = 1859,
                                      bg = bg)
    
    if (is.element("list",class(plot))) {
      purrr::walk(.x = plot, .f = print)
    } else {
      print(plot)
    }
    invisible(dev.off())
  } else if (quality == "high") {
    graphs_img <- magick::image_graph(res = 300,
                                      pointsize = 12,
                                      width = 2523,
                                      height = 2523,
                                      bg = bg)
    
    if (is.element("list",class(plot))) {
      purrr::walk(.x = plot, .f = print)
    } else {
      print(plot)
    }
    invisible(dev.off())
  }
  
  if (is.element("list",class(plot))) {
    graphs_img %>% 
      magick::image_trim() %>% 
      magick::image_border(color = "white") %>% 
      magick::image_append(stack = stack) 
    
  } else {
    graphs_img %>% 
      magick::image_trim() %>% 
      magick::image_border(color = "white")
  }
  

}