beziersimplify

{beziersimplify} is a package with methods for simplifying/flattening cubic beziers to polylines.

Three methods:

• bezier3_to_points_n() - generate points at n equally spaced points along the bezier
• bezier3_to_points_t() - generate points at locations given by parameter t (where all t values are in the range [0, 1])
• bezier3_to_points_tol() - generate enough points such that the maximum error of the resulting polyline is less than the given tolerance.

Installation

You can install the latest development version from GitHub with:

# install.package('remotes')
remotes::install_github('coolbutuseless/beziersimplify')

Create random cubic bezier for demonstration

# Random cubic bezier
set.seed(2026)
x <- runif(4)
y <- runif(4)

Plot using grid.bezier()

In all plots:

• the endpoints are marked with a black dot,
• the 2 middle control points are marked in red
• the bezier drawn with grid.bezier() shown in blue.

grid.newpage()
grid.circle(x, y, r = unit(1, 'mm'), 
            gp = gpar(fill = c('black', 'hotpink', 'hotpink', 'black'), col = NA))
grid.bezier(x, y, gp = gpar(col = 'blue'))

Simplify Cubic Bezier to n points

Creates n evenly distributed points along the

pc <- bezier3_to_points_n(x, y, 10)
pc
#>            x         y
#> 1  0.6986735 0.5553690
#> 2  0.6422822 0.4132025
#> 3  0.5724589 0.3346112
#> 4  0.4960858 0.3112193
#> 5  0.4200456 0.3346509
#> 6  0.3512206 0.3965303
#> 7  0.2964934 0.4884818
#> 8  0.2627465 0.6021295
#> 9  0.2568623 0.7290977
#> 10 0.2857233 0.8610107

Cubic Bezier at given t locations

Random locations along the bezier

t <- c(0, sort(runif(8)), 1)
t
#>  [1] 0.000000000 0.005933257 0.153835241 0.231125047 0.252501179 0.356809315
#>  [7] 0.580806337 0.691865940 0.848532462 1.000000000

pc <- bezier3_to_points_t(x, y, t)
pc
#>            x         y
#> 1  0.6986735 0.5553690
#> 2  0.6961146 0.5460333
#> 3  0.6166476 0.3759173
#> 4  0.5664895 0.3308138
#> 5  0.5520063 0.3231172
#> 6  0.4797605 0.3125503
#> 7  0.3372984 0.4150873
#> 8  0.2867535 0.5126543
#> 9  0.2553431 0.6819699
#> 10 0.2857233 0.8610107

Cubic bezier to polyline within given tolerance

Points are distributed so as to meet the error tolerance requirement using as few points as possible.

Large tolerance

pc <- bezier3_to_points_tol(x, y, tol = 0.1)
pc
#>           x         y
#> 1 0.6986735 0.5553690
#> 2 0.5294672 0.3814636
#> 3 0.4309180 0.3445682
#> 4 0.3635237 0.3815322
#> 5 0.3089539 0.5198708
#> 6 0.2857233 0.8610107

Small tolerance

pc <- bezier3_to_points_tol(x, y, tol = 0.00001)
head(pc)
#>           x         y
#> 1 0.6986735 0.5553690
#> 2 0.6906975 0.5275679
#> 3 0.6824853 0.5023608
#> 4 0.6740727 0.4795709
#> 5 0.6740727 0.4795709
#> 6 0.6646878 0.4570810