bm_trim: Trim bitmaps

In bittermelon: Bitmap Tools

Trim bitmaps

Description

bm_trim() trims bitmap objects reducing the number of pixels. The directions and amount of removed pixels are settable.

Usage

bm_trim(
  x,
  sides = NULL,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  width = NULL,
  height = NULL,
  hjust = "center-left",
  vjust = "center-top"
)

## S3 method for class 'bm_matrix'
bm_trim(
  x,
  sides = NULL,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  width = NULL,
  height = NULL,
  hjust = "center-left",
  vjust = "center-top"
)

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

## S3 method for class ''magick-image''
bm_trim(
  x,
  sides = NULL,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  width = NULL,
  height = NULL,
  hjust = "center-left",
  vjust = "center-top"
)

## S3 method for class 'nativeRaster'
bm_trim(
  x,
  sides = NULL,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  width = NULL,
  height = NULL,
  hjust = "center-left",
  vjust = "center-top"
)

## S3 method for class 'raster'
bm_trim(
  x,
  sides = NULL,
  top = NULL,
  right = NULL,
  bottom = NULL,
  left = NULL,
  width = NULL,
  height = NULL,
  hjust = "center-left",
  vjust = "center-top"
)

Arguments

x	Either a bm_bitmap(), bm_font(), bm_list(), "magick-image", "nativeRaster", bm_pixmap(), or "raster" object.
sides	If not NULL then an integer vector indicating how many pixels to trim on all four sides. If the integer vector is of length one it indicates the number of pixels for all four sides. If of length two gives first the number for the vertical sides and then the horizontal sides. If of length three gives the number of pixels for top, the horizontal sides, and then bottom sides. If of length four gives the number of pixels for top, right, bottom, and then left sides. This is the same scheme as used by the CSS padding and margin properties.
top	How many pixels to trim the top.
right	How many pixels to trim the right.
bottom	How many pixels to trim the bottom.
left	How many pixels to trim the left.
width	How many pixels wide should the new bitmap be. Use with the hjust argument or just one of either the left or right arguments.
height	How many pixels tall should the new bitmap be. Use with the vjust argument or just one of either the top or bottom arguments.
hjust	One of "left", "center-left", "center-right", "right". "center-left" and "center-right" will attempt to place in "center" if possible but if not possible will bias it one pixel left or right respectively. "centre", "center", and "centre-left" are aliases for "center-left". "centre-right" is an alias for "center-right". Note if "left" we will trim on the right (and vice-versa).
vjust	One of "bottom", "center-bottom", "center-top", "top". "center-bottom" and "center-top" will attempt to place in "center" if possible but if not possible will bias it one pixel down or up respectively. "centre", "center", and "centre-top" are aliases for "center-top". "centre-bottom" is an alias for "center-bottom". Note if "top" we will trim on the bottom (and vice-versa).
...	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.

See Also

bm_extend(), bm_pad(), and bm_resize().

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_trimmed <- bm_trim(capital_r, c(1, 1, 3, 0))
print(capital_r_trimmed)
corn <- farming_crops_16x16()$corn$portrait
print(bm_padding_lengths(corn))
corn_trimmed <- bm_trim(corn, top = 1L, right = 1L, bottom = 1L)
if (cli::is_utf8_output() && cli::num_ansi_colors() >= 256L) {
  print(corn_trimmed, bg = "cyan", compress = "v")
}

bittermelon documentation built on April 3, 2025, 8:51 p.m.