Create an svg file with benjamini leaves

Let’s have a look how we can be generate svg files with benjamini leaves. First we’ll load some libraries.

library(ggbenjamini)
library(dplyr)
library(purrr)
library(tidyr)
library(ggplot2)
library(stringr)
library(minisvg)
library(prismatic)

set.seed(21)

We’ll use the package example dataframe df_bezier_skeleton with the bezier paths of a “hand drawn” (with inkscape) svg file ressembling the skeleton a of a plant like structure (see vignette("import_svg_bezier") if you’re interested how to import svg file beziers) and directly grow leaves on these “branches”:

df_branches_and_leaves <- df_bezier_skeleton %>%
  group_by(i_branch) %>% 
  summarise(benjamini_branch(
    df_branch = tibble(x, y), 
    leaf_size_multiplicator = 0.5, 
    leaf_mean_dist_approx = 20, 
    leaf_angle_dist = spark_norm(mean = 0, sd = 15)
  ))
#> Warning: Returning more (or less) than 1 row per `summarise()` group was deprecated in
#> dplyr 1.1.0.
#> ℹ Please use `reframe()` instead.
#> ℹ When switching from `summarise()` to `reframe()`, remember that `reframe()`
#>   always returns an ungrouped data frame and adjust accordingly.
#> Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
#> generated.

Now we can add columns path_str with this “d” element and furthermore, we’ll define different fill_colors for the varyous types of elements and transform these to svg path strings:

get_svg_bezier_string <- function(bezier_df) {
  bezier_df %>%
    group_by(i_part) %>%
    slice(-1) %>%
    summarise(cb = paste(x, y, sep = ",", collapse = " ")) %>%
    pull(cb) %>%
    paste("C", ., collapse = " ") %>% 
    # paste("Z") %>% 
    paste0("M ", bezier_df$x[1], ",", bezier_df$y[1], " ", .)
}

size <- 640

pal <- c(
  "#faff5a", "#b65151", "#de9602", "#ff980b",
  "#fdd021", "#5c9e3f", "#fef266", "#925e16"
)
palhex <- scales::gradient_n_pal(colours = pal)


coord_intervals_lengths <- df_branches_and_leaves %>% 
  ungroup()%>% 
  summarise(
    x = range(x) %>% {.[2] - .[1]}, 
    y = range(y) %>% {.[2] - .[1]}
  )
df_svg <- df_branches_and_leaves %>% 
  mutate(
    x = x * size / coord_intervals_lengths[["x"]],
    y = y * size / coord_intervals_lengths[["y"]]
    ) %>% 
  group_by(i_branch, i_leaf, element) %>% 
  summarise(path_str =  get_svg_bezier_string(tibble(x, y, i_part))) %>% 
  mutate(fill_color = case_when(
    element == "half 1" ~ "url(#RadialGradient3)",
    element == "half 2" ~ "url(#RadialGradient4)",
    element == "stalk"  ~ "sandybrown",
    element == "branch"  ~ "brown"
  )) %>%
  group_by(i_branch, i_leaf) %>%
  # We'll define some alchemist random distribution for the color scale later:
  mutate(
    fill_var = 6 * 
      as.numeric(i_branch) + 
      i_leaf + 
      sample(1:10, 1, TRUE)
  ) %>%
  ungroup() %>% 
  mutate(hex = palhex(fill_var / max(fill_var))) %>% 
  mutate(
    fill_gradient = factor(hex) %>% 
      as.numeric() %>%
      paste0("url(#gradient", ., ")")
  ) 
  
df_svg
#> # A tibble: 910 × 8
#>    i_branch i_leaf element path_str      fill_color fill_var hex   fill_gradient
#>       <int>  <dbl> <chr>   <chr>         <chr>         <dbl> <chr> <chr>        
#>  1        1      0 branch  M 417.643954… brown             7 #DBA… url(#gradien…
#>  2        1      1 half 1  M 412.930126… url(#Radi…       13 #BB5… url(#gradien…
#>  3        1      1 half 2  M 412.930126… url(#Radi…       13 #BB5… url(#gradien…
#>  4        1      1 stalk   M 417.898908… sandybrown       13 #BB5… url(#gradien…
#>  5        1      2 half 1  M 426.168630… url(#Radi…       14 #B65… url(#gradien…
#>  6        1      2 half 2  M 426.168630… url(#Radi…       14 #B65… url(#gradien…
#>  7        1      2 stalk   M 420.192192… sandybrown       14 #B65… url(#gradien…
#>  8        1      3 half 1  M 423.284651… url(#Radi…       14 #B65… url(#gradien…
#>  9        1      3 half 2  M 423.284651… url(#Radi…       14 #B65… url(#gradien…
#> 10        1      3 stalk   M 424.327053… sandybrown       14 #B65… url(#gradien…
#> # ℹ 900 more rows

# define gradients
range_of_values <- range(df_svg$fill_var)

hex_needed <- df_svg %>% 
  transmute(
    fill_var = fill_var - min(fill_var),
    fill_var = fill_var / max(fill_var),
    hex = palhex(fill_var)
  ) %>% 
  pull(hex) %>% 
  unique()

We’re ready to create our minisvg document:

doc <- SVGDocument$new(width = size, height = size)

In order to have some more realistic texture, we’ll define gradients for the leaves:

append_gradient_def <- function(
  doc, id, col1 = "#00FF00", col2 = "#008000"
) {
  doc$append(
    stag$radialGradient(
      id = id, cx="0.35", cy="0.63", r="0.7",
      stag$stop(offset = "0%", stop_color = col1),
      stag$stop(offset = "100%", stop_color = col2)
    )
  )
  doc
}

hex_needed %>% 
  iwalk(
    ~append_gradient_def(
      doc, paste0("gradient", .y), 
      .x, 
      clr_darken(.x)
    )
  )

…and append them to the document:

# doc$append(gradients)

Here we define helper functions to append pathes as polygons or lines to the svg:

append_polygon <- function(doc, path_str, fill_color) {
  doc$append(
    stag$path(
      d = path_str,
      fill=fill_color,
      # stroke_width = "0.5",
      stroke="none",
      fill_opacity="1"
    )
  )
}
append_line <- function(doc, path_str, fill_color) {
  doc$append(
    stag$path(
      d = path_str,
      stroke_width = "2",
      fill = "none",
      stroke_linecap="round",
      stroke=fill_color
    )
  )
}
append_element <- function(type, path_str, fill_color) {
  switch (
    type,
    "half 1" = ,
    "half 2" = append_polygon(doc, path_str, fill_color),
    "branch" = ,
    "stalk"  = append_line(doc, path_str, fill_color)
  )
  
}

Now we can finally append the branches with leaves to the svg:

pwalk(list(
    df_svg$element,
    df_svg$path_str,
    df_svg$fill_gradient
  ),
  function(x, y, z) append_element(x, y, z)
)

Et voilà

doc$show()