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Shift elements within bitmaps

Source: R/bm_shift.R
bm_shift.Rd

Shifts non-padding elements within bitmaps by trimming on a specified side and padding on the other while preserving the width and height of the original bitmap.

Usage

bm_shift(
  x,
  value,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

# S3 method for class 'bm_bitmap'
bm_shift(
  x,
  value = 0L,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

# S3 method for class 'bm_list'
bm_shift(x, ...)

# S3 method for class 'bm_pixmap'
bm_shift(
  x,
  value = col2hex("transparent"),
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

# S3 method for class '`magick-image`'
bm_shift(
  x,
  value = "transparent",
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

# S3 method for class 'nativeRaster'
bm_shift(
  x,
  value = col2int("transparent"),
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

# S3 method for class 'raster'
bm_shift(
  x,
  value = "transparent",
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  overflow = "clip"
)

Arguments

x

Either a bm_bitmap(), bm_font(), bm_list(), "magick-image", "nativeRaster", bm_pixmap(), or "raster" object.

value

Value for the new pixels.

top

Number of pixels to shift towards the top side.

right

Number of pixels to shift towards the right side.

bottom

Number of pixels to shift towards the bottom side.

left

Number of pixels to shift towards the left side.

overflow

How to handle shifts that would push content off the bitmap. One of "clip", "error", or "wrap". If "clip" (the default) then content that is pushed off the bitmap is silently lost. If "error" then an error is thrown if the shift would clip any non-padding content. If "wrap" then content that is pushed off one side of the bitmap wraps around to the other side.

...

Additional arguments to be passed to or from methods.

Value

Depending on x either a bm_bitmap(), bm_font(), bm_list(), magick-image, "nativeRaster", bm_pixmap(), or raster object.

Details

This function is a convenience wrapper around bm_trim() and bm_extend().

See also

bm_trim() and bm_extend()

Examples

font_file <- system.file("fonts/spleen/spleen-8x16.hex.gz", package = "bittermelon")
font <- read_hex(font_file)
capital_r <- font[[str2ucp("R")]]
print(capital_r)
#> ░░░░░░░░
#> ░░░░░░░░
#> ██████░░
#> ██░░░██░
#> ██░░░██░
#> ██░░░██░
#> ██████░░
#> ██░░░██░
#> ██░░░██░
#> ██░░░██░
#> ██░░░██░
#> ██░░░██░
#> ░░░░░░░░
#> ░░░░░░░░
#> ░░░░░░░░
#> ░░░░░░░░
capital_r <- bm_shift(capital_r, bottom = 2L, right = 1L)
print(capital_r)
#> ░░░░░░░░
#> ░░░░░░░░
#> ░░░░░░░░
#> ░░░░░░░░
#> ░██████░
#> ░██░░░██
#> ░██░░░██
#> ░██░░░██
#> ░██████░
#> ░██░░░██
#> ░██░░░██
#> ░██░░░██
#> ░██░░░██
#> ░██░░░██
#> ░░░░░░░░
#> ░░░░░░░░
corn <- farming_crops_16x16()$corn$portrait
print(bm_padding_lengths(corn))
#>    top  right bottom   left 
#>      2      2      2      1 
corn_shifted <- bm_shift(corn, left = 1L, top = 2L)
if (cli::is_utf8_output() && cli::num_ansi_colors() >= 256L) {
  print(corn_shifted, bg = "cyan", compress = "v")
}
#>    ▄▀▀▄▄▀█      
#>   █▀▀▀▀█▀▀▄     
#>   ▄▀▀▀█▀█▀▀▀▄   
#> ▄▀▀▀█▀▀▀▀████   
#> ▀▀▀ ▀▀▀▀▀▀▀██   
#>       ▀▀▀▀▀▀    
#>                 
#>                 
corn_wrapped <- bm_shift(corn, right = 4L, overflow = "wrap")
if (cli::is_utf8_output() && cli::num_ansi_colors() >= 256L) {
  print(corn_wrapped, bg = "cyan", compress = "v")
}
#>                 
#>         ▄▀▀▄▄▀█ 
#>        █▀▀▀▀█▀▀▄
#> ▀▄     ▄▀▀▀█▀█▀▀
#> ██   ▄▀▀▀█▀▀▀▀██
#> ██   ▀▀▀ ▀▀▀▀▀▀▀
#> ▀          ▀▀▀▀▀
#>