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R6 Fractal Tree
library(R6)
library(ggplot2)
library(uuid)
options(stringsAsFactors = FALSE)
branch_base = R6Class('branch_base',
public = list(
start_x = NA_integer_,
start_y = NA_integer_,
end_x = NA_integer_,
end_y = NA_integer_,
type = NA_character_,
id = NA_character_,
branch_color = NA_character_
), # public
active = list(
df = function() {
x = c(self$start_x, self$end_x)
y = c(self$start_y, self$end_y)
data.frame(x = x, y = y,
type = self$type,
id = self$id,
branch_color = self$branch_color)
}
) # active
) # branch_base
trunk = R6Class('trunk',
inherit = branch_base,
public = list(
initialize = function(len = 10, branch_color = '#000000') {
self$start_x = 0
self$start_y = 0
self$end_x = 0
self$end_y = len
self$type = 'trunk'
self$branch_color = branch_color
self$id = uuid::UUIDgenerate()
}
) # public
) # trunk
branch = R6Class('branch',
inherit = branch_base,
public = list(
initialize = function(x, y, len = 5, theta = 45,
type = NA_character_, branch_color='#000000') {
dy = sin(theta) * len
dx = cos(theta) * len
self$start_x = x
self$start_y = y
self$end_x = x + dx
self$end_y = y + dy
self$type = type
self$id = uuid::UUIDgenerate()
self$branch_color = branch_color
}
) # public
) # branch
fractal_tree = R6Class('fractal_tree',
public = list(
delta_angle = NA_real_,
len_decay = NA_real_,
min_len = NA_real_,
branches = data.frame(),
branch_left_color = NA_character_,
branch_right_color = NA_character_,
initialize = function(trunk_len = 10,
delta_angle = pi / 8,
len_decay = 0.7,
min_len = 0.25,
trunk_color = '#000000',
branch_left_color = '#000000',
branch_right_color = '#adadad') {
self$delta_angle = delta_angle
self$len_decay = len_decay
self$min_len = min_len
self$branch_left_color = branch_left_color
self$branch_right_color = branch_right_color
self$branches = trunk$new(trunk_len, trunk_color)$df
private$grow_branches(0, trunk_len,
len = trunk_len * len_decay,
angle_in = pi / 2)
}, # initialize
plot = function() {
ggplot(tree$branches, aes(x, y, group = id, color=branch_color)) +
geom_line() +
geom_point(color = 'darkgreen', size=0.5) +
scale_color_identity() +
guides(color = FALSE, linetype = FALSE) +
theme_void()
}
), # public
private = list(
grow_branches = function(start_x, start_y,
len = 1,
angle_in = pi / 2,
parent_type = NA,
parent_color = NA) {
if (len >= self$min_len) {
l_type = if (!is.na(parent_type)) parent_type else 'left'
r_type = if (!is.na(parent_type)) parent_type else 'right'
l_color = if (!is.na(parent_color)) parent_color else self$branch_left_color
r_color = if (!is.na(parent_color)) parent_color else self$branch_right_color
branch_left = branch$new(start_x, start_y, len, angle_in + self$delta_angle, l_type, l_color)
branch_right = branch$new(start_x, start_y, len, angle_in - self$delta_angle, r_type, r_color)
self$branches = rbind(self$branches, branch_left$df, branch_right$df)
private$grow_branches(branch_left$end_x,
branch_left$end_y,
angle_in = angle_in + self$delta_angle,
len = len * self$len_decay,
parent_type = branch_left$type,
parent_color = branch_left$branch_color)
private$grow_branches(branch_right$end_x,
branch_right$end_y,
angle_in = angle_in - self$delta_angle,
len = len * self$len_decay,
parent_type = branch_right$type,
parent_color = branch_right$branch_color)
}
} # grow_branches
) # private
) # fractal_tree
tree = fractal_tree$new()
tree$plot()
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