Add a fallback palette based on Viridis

R/pal_fallback.R

@@ -0,0 +1,19 @@
+pal_fallback <- function(reverse = FALSE,
+                         color_ramp_palette = FALSE,
+                         discrete = FALSE,
+                         n = 5,
+                         ...){
+
+  pal <- if(discrete) { viridisLite::viridis(n) } else {viridisLite::magma(n)}
+
+  if (reverse) pal <- rev(pal)
+
+  if (color_ramp_palette) {
+    rlang::check_installed("grDevices", reason = "Package \"grDevices\" needed for `pal_fallback()` with 'color_ramp_palette' set to `TRUE` to work. Please install it.")
+
+    pal <- grDevices::colorRampPalette(pal, ...)
+  }
+
+  return(pal)
+
+}