R/plot_asp_native_raster.R

In rayimage: Image Processing for Simulated Cameras

#'@title Plot Native Raster with Custom Aspect Ratio
#'
#'@keywords internal
plot_asp_native_raster = function(nr, asp=1, show = FALSE, return_grob = FALSE) {
  stopifnot(asp > 0)
  native_dim = dim(nr)
  asp = asp * native_dim[2]/native_dim[1]
  if(asp > 1) {
    gl = grid::grid.layout(1,1,
                           widths=grid::unit(1, "null"),
                           heights=grid::unit(1 / asp, "null"), respect = TRUE)
  } else {
    gl = grid::grid.layout(1,1,
                           widths=grid::unit(1 * asp, "null"),
                           heights=grid::unit(1, "null"), respect = TRUE)
  }

  top.vp = grid::viewport(layout = gl,
                          name = "grid_asp_container")
  grid::pushViewport(top.vp)
  grid::pushViewport(grid::viewport(name = "image",
                                    layout.pos.col = 1,
                                    layout.pos.row = 1))

  if(!return_grob) {
    grid::grid.raster(nr,
                      interpolate = FALSE,
                      width = grid::unit(1,"npc"),
                      height = grid::unit(1,"npc"))
    return(invisible())
  } else {
    return(grid::rasterGrob(nr, interpolate = FALSE,
                            width = grid::unit(1,"npc"),
                            height = grid::unit(1,"npc")))
  }
}