Check whether an Object intersects with Line Segments

Generalization of the intersects for segments, allowing for vectorized checking of intersections with segments. Is often used within the intersects, especially when checking the intersections of polygon-class and rectangle-class. Currently works for all instances of object-class.

Usage

line_intersection(object, segments, ...)

# S4 method for class 'polygon'
line_intersection(object, segments, return_all = FALSE, cpp = TRUE)

# S4 method for class 'circle'
line_intersection(object, segments, return_all = FALSE, cpp = TRUE)

# S4 method for class 'segment'
line_intersection(object, segments, return_all = FALSE, cpp = TRUE)

Arguments

object: Object of a type that extends object-class.
segments: Numerical matrix of size N x 4 containing the coordinates of the line segments in order x_1, y_1, x_2, y_2.
...: Arguments passed on to the methods of this generic
return_all: Logical denoting whether to return a vector of logicals that denote intersections of each line separately (TRUE) or whether to only return a single logical denoting whether any intersections occurred (FALSE). Defaults to FALSE.
cpp: Logical denoting whether to use the Rcpp (TRUE) or R (FALSE) alternative of this function. Defaults to TRUE.

Value

Logical vector (return_all = TRUE) or logical (return_all = FALSE) denoting whether the lines intersect with the provided object. Whenever there is an intersection, the logical is TRUE and otherwise, the logical is FALSE.

Details

Note that while rectangle-class is not explicitly mentioned here, this method does work for this class of objects.

Examples

# Create two objects that intersect with each other, and check their 
# intersection
my_circle <- circle(center = c(0, 0), radius = 1)
my_lines <- rbind(c(0, 0, 2, 2), 
                  c(0, 2, 2, 2))

line_intersection(my_circle, my_lines)
#> [1] TRUE