create_benjamini_svg.Rmd

---
title: "Create an svg file with benjamini leaves"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Create an svg file with benjamini leaves}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  message = FALSE
)
```

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

```{r setup, message=FALSE}
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":


```{r}
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)
  ))

```


Now we can add columns `path_str` with this "d" element and furthermore, we'll
define different `fill_color`s for the varyous types of `element`s and
transform these to svg path strings:


```{r}
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], " ", .)
}
```



```{r}
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
```


```{r}
# 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:
```{r}
doc <- SVGDocument$new(width = size, height = size)
```

In order to have some more realistic texture, we'll define gradients for the leaves:
```{r}
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:
```{r}
# doc$append(gradients)
```

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

```{r}
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:


```{r}
pwalk(list(
    df_svg$element,
    df_svg$path_str,
    df_svg$fill_gradient
  ),
  function(x, y, z) append_element(x, y, z)
)

```




Et voilà

```{r, eval=FALSE}
doc$show()
```

```{r, echo=FALSE}
doc$save("svg_vignette_output.svg")
rsvg::rsvg_png("svg_vignette_output.svg", "svg_vignette_output.png")
knitr::include_graphics("svg_vignette_output.png")
```