widen_paths {mazing}

Spread a value within a matrix

Description

A function to spread a particular value into neighboring cells of a matrix. When that matrix is a binary representation of a maze, this can be used to widen the paths of the maze (subsequently narrowing the walls).

Usage

widen_paths(m, value = 1, blocked = NULL, square_corners = FALSE)

Arguments

m

A matrix.

value

The value to be expanded into neighboring cells. For widening the paths of the maze, this is the value that represents paths.

blocked

Values that should be preserved, regardless of whether or not the expansion would normally encroach on their cells.

square_corners

Whether or not to include diagonals in the expansion. Including diagonals will preserve square corners, whereas excluding them (default) creates more rounded looking corners.

Details

The idea of this function is to let the paths of a maze "seep" into the walls. For making a maze-within-a-maze, the walls of the big maze are generally not as interesting as the paths, which contain smaller paths. Hence why we might want to make the paths wider than the walls. Remember that this will affect walls from both sides, so it is necessary to expand the matrix twice (via expand_matrix) before widening the paths for the first time.

Value

A matrix with the same dimensions as the original, in which cells that border a cell of a particular value have been assigned that value.

Examples

m <- matrix(0, nrow = 5, ncol = 5)
m[3,3] <- 1
widen_paths(m)
widen_paths(m, square_corners = TRUE)

m[,2] <- 2
widen_paths(m, blocked = 2)