Package {nara}

nara: Native Raster Image Tools

Description

Native rasters are a core R image format which use a compact color representation. This color representation closely aligns with graphics device internals meaning that these images can be rendered quickly. This package provides functions to quickly create, manipulate and composite native rasters.

Author(s)

Maintainer: Mike Cheng mikefc@coolbutuseless.com [copyright holder]

Other contributors:

• Julien Vernay (Author of public domain code for thick polylines) [contributor]

See Also

Useful links:

• https://github.com/coolbutuseless/nara

• https://coolbutuseless.github.io/package/nara/index.html

• Report bugs at https://github.com/coolbutuseless/nara/issues

Deer images - a list of native raster images

Description

The 'deer' sprites are by Calciumtrice and licensed under CC BY 3.0. See 'inst/LICENSE-deer.txt' for more details. To view license information:

Usage

deer

Format

An object of class list of length 15.

Details

cat(readLines(system.file('LICENSE-deer.txt', package = 'nara')), sep = "\n")

Check if object is a native raster image

Description

Check if object is a native raster image

Usage

is_nativeraster(x)

Arguments

Value

logical. TRUE if object is a native raster image

Examples

is_nativeraster(mtcars)

nr <- nr_new(100, 100)
is_nativeraster(nr)

Convert a 'magick' image to native raster image

Description

Convert a 'magick' image to native raster image

Usage

magick_to_nr(im, dst = NULL)

nr_to_magick(nr)

Arguments

Value

New native raster image

See Also

Other conversion functions: matrix_to_nr(), nr_to_raster(), nrs_to_gif(), nrs_to_mp4()

Other conversion functions: matrix_to_nr(), nr_to_raster(), nrs_to_gif(), nrs_to_mp4()

Examples

im <- magick::logo
nr <- magick_to_nr(im)
plot(nr)

Convert a numeric matrix to native raster image

Description

Convert a numeric matrix to native raster image

Usage

matrix_to_nr(mat, palette, fill = "transparent", min = 0, max = 1, dst = NULL)

Arguments

Value

native raster image

See Also

Other conversion functions: magick_to_nr(), nr_to_raster(), nrs_to_gif(), nrs_to_mp4()

Examples

# integer matrix
m <- matrix(1:12, 3, 4)
m
palette <- rainbow(12)
nr <- matrix_to_nr(m, palette) 
plot(nr)


# numeric matrix
m <- matrix(runif(20 * 30), 20, 30)
palette <- c('red', 'blue', 'black', 'green', 'blue', 'yellow')
nr <- matrix_to_nr(m, palette)
plot(nr)

Copy a native raster image into another at an arbitrary location, scale and rotation

Description

Copy a whole image, or subset of an image, into the destination image and configure the angle and size of the copied image.

Usage

nr_blit(
  dst,
  src,
  x,
  y,
  xsrc = 0L,
  ysrc = 0L,
  w = -1L,
  h = -1L,
  hjust = 0.5,
  vjust = 0.5,
  angle = 0,
  scale = 1,
  use_alpha = TRUE
)

Arguments

Details

This operation is vectorised such that a single src image can be pasted multiple times into the dst image with varying location, angle and scale.

Value

Invisibly return the supplied dst native raster image which was been modified in-place

See Also

Other blitting functions: nr_blit_multi()

Examples

nr <- nr_new(50, 50, 'grey80')
nr_blit(dst = nr, src = deer[[1]], x = 25, y = 25)
plot(nr)

nr <- nr_new(300, 200, 'grey80')
sq <- nr_new(20, 20, 'darkblue')
nr_blit(nr, src = sq, x = 100, y = 100, angle = pi/3, scale = 5)
plot(nr)

nr <- nr_new(800, 600, 'grey80')
sq <- fastpng::read_png(system.file("image/deer-1.png", package="nara"), type = 'nativeraster')
nr_blit(nr, src = sq, x = 300, y = 240, angle = pi/2, scale = 1)
plot(nr)

Multiple blit operations in a single call

Description

Multiple blit operations in a single call

Usage

nr_blit_multi(dst, src, config)

Arguments

Value

Invisibly return the supplied dst native raster image which was been modified in-place

See Also

Other blitting functions: nr_blit()

Examples

nr <- nr_new(90, 90, 'grey60')

config <- data.frame(
  idx = c(1, 2, 3, 4),
  x = c(10, 10, 40, 40) + 15,
  y = c(10, 40, 40, 10) + 15,
  xsrc = 0L,
  ysrc = 0L,
  w = -1L,
  h = -1L,
  hjust = 0.5,
  vjust = 0.5,
  angle = c(0, 0, 0, pi/4),
  scale = c(0.5, 1, 1, 1),
  use_alpha = TRUE,
  render = TRUE
)

nr_blit_multi(dst = nr, src = deer, config = config)
plot(nr)

Draw circles on a native raster image

Description

Draw circles on a native raster image

Usage

nr_circle(nr, x, y, r, fill = "black", color = NA, use_alpha = TRUE)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other drawing functions: nr_polygon(), nr_polyline(), nr_rect(), nr_tri_mesh()

Examples

set.seed(1)
w <- 200
h <- 150
nr <- nr_new(w, h, 'black')

N <- 10
coords <- expand.grid(x = seq(2, w, length.out = N), 
                      y = seq(2, h, length.out = N))

cols <- sample(grDevices::terrain.colors(nrow(coords)))

nr_circle(
  nr,
  x = coords$x,
  y = coords$y,
  r = w/N/1.3,
  fill = cols
)
plot(nr)

Replace colors in a native raster image

Description

Replace colors in a native raster image

Usage

nr_color_replace(nr, old, new)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other color manipulation functions: nr_desaturate(), nr_dither(), nr_threshold()

Examples

nr <- nr_new(10, 10, 'hotpink')
nr_color_replace(nr, 'hotpink', 'grey80')
plot(nr)

Create a new native raster image and copy the dimensions and contents from an existing image

Description

Create a new native raster image and copy the dimensions and contents from an existing image

Usage

nr_copy(nr)

Arguments

Value

New native raster image

See Also

Other image creation functions: nr_new()

Examples

nr1 <- nr_new(200, 200, 'hotpink')
nr2 <- nr_copy(nr1)
plot(nr2)

Copy the contents of one native raster image into another.

Description

The source and destination native raster images must have the same dimensions.

Usage

nr_copy_into(dst, src)

Arguments

Details

If the native raster images are of different sizes or alpha blending is required, use the nr_blit() function.

Value

Invisibly return the supplied 'dst' native raster image which was been modified in-place

Examples

nr1 <- nr_new(200, 100, 'hotpink')
nr2 <- nr_new(200, 100, 'green')
nr_copy_into(nr1, nr2)
plot(nr1)

Crop a section out of a native raster image into a new image

Description

Crop a section out of a native raster image into a new image

Usage

nr_crop(nr, x, y, w, h)

nr_crop2(nr, loc)

Arguments

Value

New native raster image

Examples

nr <- deer[[1]]
dim(nr)
plot(nr)

nr2 <- nr_crop(nr, 16, 0, 16, 16)
dim(nr2)
plot(nr2)

Move image colors to gray

Description

Move image colors to gray

Usage

nr_desaturate(nr, factor = 1)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other color manipulation functions: nr_color_replace(), nr_dither(), nr_threshold()

Examples

plot(deer[[1]])
nr <- deer[[1]] |> nr_copy()

nr_desaturate(nr)
plot(nr)

Dither to binary image

Description

Dither to binary image

Usage

nr_dither(nr, value = 0.5, algo = "fs")

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other color manipulation functions: nr_color_replace(), nr_desaturate(), nr_threshold()

Examples

nr <- nr_copy(deer[[1]])
plot(nr)

nr_dither(nr, 0.99)
plot(nr)

Fill a native raster image with the given color

Description

Fill a native raster image with the given color

Usage

nr_fill(nr, color)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

Examples

nr <- nr_new(400, 300, 'hotpink')
nr_fill(nr, 'blue')
plot(nr)

Flip a native raster image horizontally

Description

Flip a native raster image horizontally

Usage

nr_fliph(nr)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other transformation functions: nr_flipv(), nr_rotate(), nr_transpose()

Examples

nr <- nr_new(400, 200, 'white')
nr_rect(nr, 0, 0, 30, 15)
plot(nr)
nr_fliph(nr)
plot(nr)

Flip a native raster image vertically

Description

Flip a native raster image vertically

Usage

nr_flipv(nr)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other transformation functions: nr_fliph(), nr_rotate(), nr_transpose()

Examples

nr <- deer[[1]] |> nr_copy()
plot(nr)
nr_flipv(nr)
plot(nr)

Draw lines on a native raster image

Description

Uses Bresenham's algorithm to draw lines. No antialiasing.

Usage

nr_line(nr, x1, y1, x2, y2, color = "black", linewidth = 1, use_alpha = TRUE)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

Examples

w <- 200
h <- 150
nr <- nr_new(w, h, 'grey80')

N <- 40
nr_line(
  nr,
  x1 = seq(0, 2*w, length.out =  N), y1 = 0,
  x2 = 0, y2 = seq(0, 2 * h, length.out = N),
  color = rainbow(N)
)

plot(nr)

Start/end region of masked drawing

Description

These functions are used to globally set a mask which determines where pixels are affected by drawing functions.

Usage

nr_mask_begin(nr, mask)

nr_mask_end(nr)

Arguments

Details

Drawing operations between nr_mask_begin() and nr_mask_end() calls will only affect pixels where the mask is not transparent.

Value

Invisibly return the original native raster image which has been modified in-place

Examples

mask <- deer[[1]] |> nr_resize(600, 400)
plot(mask)
nr <- nr_new_from(mask)

nr_mask_begin(nr, mask = mask)
nr_circle(nr, 300, 200, 200, fill = 'blue', color = 'black')
nr_circle(nr, 350, 200, 100, fill = 'darkgreen', color = 'black')
nr_mask_end(nr)

plot(nr)

Create a native raster image

Description

A native raster image in R looks like an integer matrix, but is interpreted differently by graphics devices:

Usage

nr_new(width, height, fill = "white")

nr_new_from(nr, fill = "white")

Arguments

Details

• The data should be treated as RGBA pixels in row-major ordering

• Each 32-bit integer should be interpreted as 4-bytes - one for each of the R, G, B and A color channels

Value

native raster image

See Also

Other image creation functions: nr_copy()

Examples

nr <- nr_new(400, 300, 'hotpink')
plot(nr)

Draw points on a native raster image

Description

Draw points on a native raster image

Usage

nr_point(nr, x, y, color = "black", use_alpha = TRUE)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

Examples

w <- 200
h <- 150
nr <- nr_new(w, h, 'grey80')

coords <- expand.grid(x = seq(w) - 1, y = seq(h) - 1)
cols   <- sample(rainbow(nrow(coords)))
nr_point(nr, x = coords$x, y = coords$y, color = cols) 
plot(nr)

Draw multiple polygons on a native raster image

Description

Draw multiple polygons on a native raster image

Usage

nr_polygon(
  nr,
  x,
  y,
  id = NULL,
  fill = "black",
  color = NA,
  linewidth = 1,
  mitre_limit = linewidth,
  use_alpha = TRUE
)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other drawing functions: nr_circle(), nr_polyline(), nr_rect(), nr_tri_mesh()

Examples

w <- 200
h <- 150
nr <- nr_new(w, h, 'grey80')

N  <- 20
theta <- seq(0, 2 * pi, length.out = N)
xs <- w/2 + 50 * cos(theta)
ys <- h/2 + 50 * sin(theta)

nr_polygon(nr, xs, ys, fill = 'grey50', col = 'black')
nr_point(nr, xs, ys, col = 'red')
plot(nr)

Draw a polyline on a native raster image

Description

Draw a polyline on a native raster image

Usage

nr_polyline(
  nr,
  x,
  y,
  color = "black",
  linewidth = 1,
  mitre_limit = linewidth,
  close = FALSE,
  use_alpha = TRUE
)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other drawing functions: nr_circle(), nr_polygon(), nr_rect(), nr_tri_mesh()

Examples

w <- 200
h <- 150
nr <- nr_new(w, h, 'grey80')

N  <- 20
theta <- seq(0, 2 * pi, length.out = N)
xs <- w/2 + 50 * cos(theta)
ys <- h/2 + 50 * sin(theta)

nr_polyline(nr, xs, ys)
nr_point(nr, xs, ys, col = 'red')
plot(nr)

Draw rectangles on a native raster image

Description

Draw rectangles on a native raster image

Usage

nr_rect(
  nr,
  x,
  y,
  w,
  h,
  fill = "black",
  color = NA,
  hjust = 0,
  vjust = 0,
  linewidth = 1,
  use_alpha = TRUE
)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other drawing functions: nr_circle(), nr_polygon(), nr_polyline(), nr_tri_mesh()

Examples

set.seed(1)
w <- 200
h <- 150
nr <- nr_new(w, h, 'grey80')

N <- 10
coords <- expand.grid(x = seq(2, w, length.out = N), 
                      y = seq(2, h, length.out = N))

cols <- sample(grDevices::heat.colors(nrow(coords)))

nr_rect(
  nr,
  x = coords$x,
  y = coords$y,
  w = w/N - 1,
  h = h/N - 1,
  fill = cols
)
plot(nr)

Resize a native raster by specifying the output dimensions

Description

Resize a native raster by specifying the output dimensions

Usage

nr_resize(nr, width, height, algo = "nn")

Arguments

Value

New native raster image

See Also

Other resizing functions: nr_scale()

Examples

stretched <- deer[[1]] |> 
    nr_copy() |> 
    nr_resize(100, 40, algo = 'nn')
plot(stretched)

Rotate a native raster image by 90,180,270 degrees

Description

Rotate a native raster image by 90,180,270 degrees

Usage

nr_rotate(nr, angle)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other transformation functions: nr_fliph(), nr_flipv(), nr_transpose()

Examples

nr <- nr_new(20, 10, 'hotpink')
dim(nr)
nr_rotate(nr, 90)
dim(nr)

Resize a native raster image using a scale factor

Description

Resize a native raster image using a scale factor

Usage

nr_scale(nr, scale, algo = "nn")

Arguments

Value

New native raster image

See Also

Other resizing functions: nr_resize()

Examples

big <- deer[[1]] |> nr_scale(2)
plot(big)

Draw text on a native raster image using the built-in monospaced bitmapped font.

Description

The only font currently available is 'spleen' - a monospace bitmap font from: https://github.com/fcambus/spleen

Usage

nr_text_mono(
  nr,
  x,
  y,
  str,
  color = "black",
  fontsize = 8L,
  hjust = 0.5,
  vjust = 0.5,
  use_alpha = TRUE
)

Arguments

Details

The 'spleen' font is licensed under BSD and the license is included in this package as "LICENSE-spleen.txt". To view LICENSE:

cat(readLines(system.file('LICENSE-spleen.txt', package = 'nara')), sep = "\n")

Value

Invisibly return the supplied native raster image which was been modified in-place

Examples

w <- 150
h <- 30
nr <- nr_new(w, h, 'grey80')

nr_text_mono(nr, x = w/2, y = h/2, str = "Hello RStats!", fontsize = 16)
plot(nr)

nr <- nr_new(w, h, 'grey80')
nr_text_mono(nr, x = 0, y = 0, str = "Hello RStats!", hjust = 0, vjust = 1, fontsize = 16)
plot(nr)

Threshold to binary image

Description

Threshold to binary image

Usage

nr_threshold(nr, value = 0.5)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other color manipulation functions: nr_color_replace(), nr_desaturate(), nr_dither()

Examples

nr <- nr_copy(deer[[1]])
plot(nr)

nr_threshold(nr, 0.9)
plot(nr)

Convert native raster images to/from other R objects

Description

Convert native raster images to/from other R objects

Usage

nr_to_raster(nr)

raster_to_nr(ras, dst = NULL)

nr_to_array(nr)

array_to_nr(arr, dst = NULL)

Arguments

Value

raster, array or native raster image

See Also

Other conversion functions: magick_to_nr(), matrix_to_nr(), nrs_to_gif(), nrs_to_mp4()

Examples

nr <- nr_new(12, 8, 'hotpink')
nr_to_raster(nr)

nr_to_array(nr)

Transpose

Description

Transpose

Usage

nr_transpose(nr)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other transformation functions: nr_fliph(), nr_flipv(), nr_rotate()

Examples

nr <- nr_new(20, 10, 'hotpink')
dim(nr)
nr_transpose(nr)
dim(nr)

Draw multiple triangles from mesh data

Description

Mesh data is a similar format to the mesh3d class of data defined in the rgl package.

Usage

nr_tri_mesh(nr, vertices, indices, color, tris = "all", use_alpha = TRUE)

nr_tri_coords(nr, coords, color, tris = "all", use_alpha = TRUE)

Arguments

Value

Invisibly return the supplied native raster image which was been modified in-place

See Also

Other drawing functions: nr_circle(), nr_polygon(), nr_polyline(), nr_rect()

Examples

#' Using direct coordinates
set.seed(1)
w <- 100
h <-  80
nr <- nr_new(w, h)

n_tri <- 10
xs <- runif(n_tri * 3, 0, w - 1)
ys <- runif(n_tri * 3, 0, h - 1)
coords <- rbind(xs, ys)
cols <- rainbow(n_tri)

nr_tri_coords(nr, coords, cols, tris = 'all')
plot(nr)

# Using a standard mesh structure
# i.e. a matrix of vertices, and a matrix of indices 
nr <- nr_new(w, h)

# Matrix of coordinates
xs <- rep(seq(0, w - 1, length.out = 10), 10)
ys <- rep(seq(0, h - 1, length.out = 10), each = 10)
vertices <- rbind(xs, ys)
nr_point(nr, xs, ys)

plot(nr)

# Matrix of indices indicating which vertices make up each triangle
indices <- matrix(sample(length(xs), 3 * n_tri), nrow = 3) 

nr_tri_mesh(nr, vertices, indices, cols, tris = 'all')
plot(nr)

Convert a list of native rasters to an animated gif

Description

Convert a list of native rasters to an animated gif

Usage

nrs_to_gif(nr_list, filename, verbose = FALSE, framerate = 30, ...)

Arguments

Value

None.

See Also

Other conversion functions: magick_to_nr(), matrix_to_nr(), nr_to_raster(), nrs_to_mp4()

Examples

im <- magick::logo
nr1 <- magick_to_nr(im)
nr2 <- nr_copy(nr1)
nrs_to_gif(list(nr1, nr2), "nothing.gif")

Convert a list of native rasters to an mp4 video file

Description

Convert a list of native rasters to an mp4 video file

Usage

nrs_to_mp4(nr_list, filename, verbose = FALSE, ...)

Arguments

Value

None.

See Also

Other conversion functions: magick_to_nr(), matrix_to_nr(), nr_to_raster(), nrs_to_gif()

Examples

im <- magick::logo
nr1 <- magick_to_nr(im)
nr2 <- nr_copy(nr1)
nrs_to_mp4(list(nr1, nr2), "nothing.mp4")

Plot a native raster image (after first clearning the device)

Description

Plot a native raster image (after first clearning the device)

Usage

## S3 method for class 'nativeRaster'
plot(x, y, ...)

Arguments

Value

Invisibly return the supplied native raster image

Examples

nr <- nr_new(200, 100, 'hotpink')
plot(nr)

Print method

Description

Print method

Usage

## S3 method for class 'nativeRaster'
print(x, ...)

Arguments

Value

None

Examples

nr <- nr_new(500, 400)
print(nr)

A list of nativeraster tiles used for constructing a side-scrolling game.

Description

The tiles in this list are of a common base size and can be conbined to construct various scenes.

Usage

tileset

Format

An object of class list of length 44.

A data.frame of configuration information which can be used with nr_blit_multi() and the tileset data.

Description

Use this configuration wtih nr_blit_multi()

Usage

tileset_config

Format

An object of class spec_tbl_df (inherits from tbl_df, tbl, data.frame) with 51 rows and 6 columns.