Add support for native rasters to annotation_raster() #3388 (#3794)

Closes #3388.

Author: kent37

NEWS.md

@@ -1,5 +1,8 @@
 # ggplot2 (development version)
 
+* `annotation_raster()` adds support for native rasters. For large rasters,
+  native rasters render significantly faster than arrays (@kent37, #3388)
+  
 # ggplot2 3.3.0
 
 * Fix a bug in `geom_raster()` that squeezed the image when it went outside 

R/annotation-raster.r

@@ -10,7 +10,7 @@ NULL
 #' of the raster, and the raster must already have its own colours). This
 #' is useful for adding bitmap images.
 #'
-#' @param raster raster object to display
+#' @param raster raster object to display, may be an `array` or a `nativeRaster`
 #' @param xmin,xmax x location (in data coordinates) giving horizontal
 #'   location of raster
 #' @param ymin,ymax y location (in data coordinates) giving vertical
@@ -39,7 +39,8 @@ NULL
 #'   geom_point()
 annotation_raster <- function(raster, xmin, xmax, ymin, ymax,
                               interpolate = FALSE) {
-  raster <- grDevices::as.raster(raster)
+  if (!inherits(raster, 'nativeRaster'))
+    raster <- grDevices::as.raster(raster)
 
   layer(
     data = dummy_data(),