Package 'nara'

Title: 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.
Authors: Mike Cheng [aut, cre, cph], Julien Vernay [ctb] (Author of public domain code for thick polylines)
Maintainer: Mike Cheng <[email protected]>
License: MIT + file LICENSE
Version: 1.0.2
Built: 2026-05-28 11:08:17 UTC
Source: https://github.com/coolbutuseless/nara

Help Index

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

x

object to check

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

im

image from the magick package
dst

destination native raster image. If NULL (the default) a new native raster image will be created If a native raster image is supplied here, it must have the exact dimensions to match the matrix
nr

native raster image

Value

New native raster image

See Also

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

mat

integer matrix
palette

vector of colors. For an integer matrix, this palette must contain at least as many colors as the maximum integer value in mat. For a numeric matrix, any length palette is allowed, and the nearest corresponding color is chosen (no interpolation is done).
fill

Color to be used for values < 1 when input is an integer matrix. Default: 'transparent'.
min, max

assumed range for the numeric data. values from the palette will be interpolated using this range as the extents. An error will occur if a value lies outside this range. Default: (0, 1)
dst

destination native raster image. If NULL (the default) a new native raster image will be created If a native raster image is supplied here, it must have the exact dimensions to match the matrix

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

dst, src

source and destination native raster images
x, y

Location in dst to place the src image. These values must be vectors of the same length. If the length is greater than 1, then the src will be pasted into dst at multiple locations.
xsrc, ysrc

Upper-left coordinates of the bounding box within the src image to copy. Default: (0, 0)
w, h

Width and height of the bounding box within the src to copy. If size is negative, then the actual width/height of the src is used. Default: (-1, -1)
hjust, vjust

specify horizontal and vertical justification of the handle on the src image to be placed at (x, y) within the dst image. Default (0, 0) is to use the top-left corner of the image as the handle. Use (0.5, 0.5) to centre the src image at the dst location (x, y)
angle

Rotation angle (clockwise) in radians. Default: 0. If this is a vector, then the src will be pasted into the dst at multiple angles.
scale

Zoom factor. Default: 1. IF this is a vector, then the src will be pasted into dst at multiple scales.
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

dst

destination native raster
src

list of native raster images.
config

data.frame of configuration information for each blit. Columns in this data.frame match the arguments to nr_blit(). Requires columns:

idx

The index of the image in the src list i.e. src[[idx]]

x,y

location in dst to place src[[idx]]

Optional columns which take a default value if not present:

xsrc,ysrc

start coordinates within src. Default: (0, 0)

w,h

size within src. Default: use whole width/height

hjust,vjust

Default: (0.5, 0.5)

angle

Default: 0

scale

Zoom factor. Default: 1

use_alpha

Default: true

render

Should this given operation be rendered? Default: true

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

nr

native raster image
x, y

coordinates of centre of circle. [vector]
r

radius [vector]
fill

interior fill color [vector]
color

outline color. Default: NA. [vector]
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
old

Vector of old colors
new

Vector of replacement colors

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

nr

native raster image

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

src, dst

Source and destination native raster images

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

nr

native raster image
x, y, w, h

dimensions of cropped section
loc

dimensions of cropped section. A vector of 4 values i.e. c(x, y, w, h)

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

nr

native raster image
factor

desaturation factor. Default: 1 (fully desaturate)

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

nr

native raster image
value

Threshold value. Default: 0.5 (valid range [0, 1])
algo

Dithering algorithm. 'fs' (floyd-steinberg) or 'atkinson'. Default: 'fs'

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

nr

native raster image
color

Color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb

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

nr

native raster image

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

nr

native raster image

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

nr

native raster image
x1, y1, x2, y2

Vectors of coordinates of endpoints of line
color

Color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb
linewidth

Line linewidth. Default: 1. If linewidth = 1 then a naive version of Bresenham is used to draw the points. If linewidth is greater than 1, then the line is convert to a triangle strip and rendered as polygons.
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
mask

native raster image to use as mask. Must be the same size as nr.

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

width, height

Image dimensions in pixels
fill

Background fill color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb
nr

native raster image to use as the template for the size of the new image in nr_new_from()

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

nr

native raster image
x, y

Vectors of point coordinates
color

Vector of colors
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
x, y

Vectors of point coordinates
id

integer vector used to separate coordinates into multiple polygons. Consecutive runs of the same id value belong to the same polygon. If NULL (the default) then all coordinates are assumed to be vertices of a single polygon.
fill

fill color
color

Color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb
linewidth

Line linewidth. Default: 1. If linewidth = 1 then a naive version of Bresenham is used to draw the points. If linewidth is greater than 1, then the line is convert to a triangle strip and rendered as polygons.
mitre_limit

Limit the size of the mitre when two lines meet at an acute angle and linewidth is greater than 1. Default: same as line linewidth which mostly looks OK.
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
x, y

Vectors of point coordinates
color

Color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb
linewidth

Line linewidth. Default: 1. If linewidth = 1 then a naive version of Bresenham is used to draw the points. If linewidth is greater than 1, then the line is convert to a triangle strip and rendered as polygons.
mitre_limit

Limit the size of the mitre when two lines meet at an acute angle and linewidth is greater than 1. Default: same as line linewidth which mostly looks OK.
close

Should the polyline be closed? I.e. should a line be drawn between the last point and the first point? Default: FALSE
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
x, y

coordinates of lower left corner of rectangle. [vector]
w, h

width and height of rectangle. [vector]
fill

interior fill color [vector]
color

outline color. Default: NA. [vector]
hjust, vjust

specify horizontal and vertical justification of the handle on the src image to be placed at (x, y) within the dst image. Default (0, 0) is to use the top-left corner of the image as the handle. Use (0.5, 0.5) to centre the src image at the dst location (x, y)
linewidth

Line linewidth. Default: 1. If linewidth = 1 then a naive version of Bresenham is used to draw the points. If linewidth is greater than 1, then the line is convert to a triangle strip and rendered as polygons.
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
width, height

dimensions for output image
algo

'nn' for nearest neighbor (the default), or 'bilinear' for bilinear interpolation.

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

nr

native raster image
angle

one of 0,90,180,270

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

nr

native raster image
scale

scale factor
algo

'nn' for nearest neighbor (the default), or 'bilinear' for bilinear interpolation.

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

nr

native raster image
x, y

coordinates of lower-left corner of text
str

character string
color

Color as a character string. Either a standard R color (e.g. 'blue', 'white') or a hex color of the form #rrggbbaa, #rrggbb, #rgba or #rgb
fontsize

height of font in pizels. Only valid values are 8, 12 and 16. Default: 8.
hjust, vjust

Justification of text relative to its (x,y) location. Default (0.5, 0.5) to centre the text at (x, y)
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE

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

nr

native raster image
value

Threshold value. Default: 0.5 (valid range [0, 1])

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

nr

native raster image
ras

standard R raster i.e. a character matrix of hex color values
dst

destination native raster image. If NULL (the default) a new
arr

3d numeric array representing R,G,B,A values with dimensions [nrow, ncol, 4] or [nrow, ncol, 3]. Each value is in range [0,1].

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

nr

native raster image

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

nr

native raster image
vertices

Wide matrix of vertex coordinates where the first two rows are x and y coordinates. Extra coordinates are ignored.
indices

3xN wide integer matrix of index information. Each column holds the 3 indices which indicate the column index of the triangle vertices defined in the vertices argument.
color

color specification. Single color or one color per tri
tris

Which triangles should be drawn? Valid options: 'all' (default), 'ccw', 'cw'. The options 'ccw' and 'cw' limit plotting to those triangles where the order of the vertices are defined in a counter-clockwise or clockwise manner respectively. Note: when considering orientation or triangles remember that the y-axis is defined vertically down the screen.
use_alpha

Use alpha channel when drawing? Logical. Default: TRUE
coords

Wide numeric matrix of direct coordinate data for each triangle where the first two rows are x and y coordinates (extra rows are ignored) Each group of 3 columns defines the (x,y) coordinates for one triangle.

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

nr_list

list of native raster image
filename

filename of gif
verbose

logical. default FALSE
framerate

frames per second
...

other arguments passed to magick::image_write_gif()

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

nr_list

list of native raster image
filename

mp4 filename
verbose

logical. default FALSE
...

other arguments passed to magick::image_write_video()

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

x

native raster image
y

ignored
...

other arguments passed to grid::grid.raster()

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

x

native raster image
...

ignored

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.