Tiling pattern

[yutannihilation]

No description provided.

[yutannihilation]

It turned out the implementation #23 was wrong. Paul Murrel's blog post says:

If the device implements patterns, it must return a pattern reference (as an R object) as the return value from this function. This reference is passed back to the device via R_GE_gcontent.patternFill.

but #23 doesn't implement this. This was the reason of #24 (because it always uses the pattern fill)

[yutannihilation]

Why doesn't this work...?

library(grid)

pat <- pattern(
  circleGrob(
    r = unit(0.1, "npc"),
    gp = gpar(col = NA, fill = "grey")
  ),
  width = unit(0.2, "npc"),
  height = unit(0.2, "npc"),
  extend = "repeat"
)
pushViewport(viewport(gp = gpar(fill = pat)))
grid.rect(width = .5, x = 0.1)

[yutannihilation]

It seems the reason is just that I don't understand how to use Image for brush. Let's merge this for now.

linebender/vello#724