Pattern Creation

library(ingrid)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Ensure that images are rendered using a device which understands patterns
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knitr::opts_chunk$set(dev.args = list(png = list(type = "cairo")))

Creating patterns

Creating patterns isn’t drastically different in ingrid compared to using the grid::pattern() function.

The changes in ingrid::ig_pattern():

• default units are globally defined (and are set to ‘npc’ by default)
  • using ‘static’ units like mm and cm make it a little easier to reason about pattern extents
• default extend is set to ‘repeat’ rather than ‘pad’

library(grid)
library(ingrid)
register_verbose_printing()


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create check pattern
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check <- igl_row(
  igl_col(
    ig_rect(fill = 'black'),
    nullGrob()
  ),
  igl_col(
    nullGrob(),
    ig_rect(fill = 'black')
  )
)

grid.newpage(); grid.draw(check)

grob <- ig_circle(fill = ig_pattern(check, width = .cm(3), height = .cm(3)))
grid.newpage(); grid.draw(grob)