test-raster.R
In ragg: Graphic Devices Based on AGG

render_raster <- function(raster, interpolate, angle) {
  dev <- agg_capture()
  plot.new()
  graphics::rasterImage(raster, 0.25, 0.25, 0.75, 0.75, angle = angle, interpolate = interpolate)
  out <- dev()
  dev.off()
  out
}

test_that("raster works", {
  image <- matrix(grDevices::hcl(0, 80, seq(50, 80, 10)), nrow = 4, ncol = 5)
  raster <- table(render_raster(image, FALSE, 0))
  expect_equal(raster[['#E16A86']], 7380)
  expect_equal(raster[['#FFA2BC']], 7200)
  
  raster <- table(render_raster(image, TRUE, 0))
  expect_equal(raster[['#E16A86']], 180)
  expect_equal(raster[['#FFA2BC']], 3780)
  
  raster <- table(render_raster(image, FALSE, 30))
  expect_equal(raster[['#E16A86']], 7227)
  expect_equal(raster[['#FFA2BC']], 7127)
  
  raster <- table(render_raster(image, TRUE, 30))
  expect_equal(raster[['#E16A86']], 255)
  expect_equal(raster[['#FFA2BC']], 3628)
})