---
title: "Using vector fonts"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Using vector fonts}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

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

```{r setup}
library(lofifonts)
```





### Vector Fonts: included fonts

```{r}
names(font_info$vector)
```

| Type   | Name            | Sizes                         | Unicode?              | # glyphs |
|--------|-----------------|-------------------------------|-----------------------|----------|
| Vector | gridfont        |                               | Lower case ASCII only |          |
| Vector | gridfont_smooth |                               | Lower case ASCII only |          |
| Vector | arcade          |                               | Upper case ASCII only |          |


## Vector font: functions

* `vector_text_coords()` returns a data.frame of strokes
* `vector_text_matrix()` returns a binary matrix with pixel locations set to 1
* `vector_text_raster()` returns a raster image of the text



## Vector font: Rendering text

Text may be rendered with a vector font to 

1. A data.frame of stroke endpoints
2. A binary matrix of pixel locations
3. A simple `raster` object 

```{r vector-coords, fig.height = 3}
library(lofifonts)
vector_text_coords("Hello", font = 'gridfont_smooth') |> 
  head()
```


```{r vector-matrix, fig.height = 3}
vector_text_matrix("Hello", "gridfont_smooth", scale = 1) 
```


```{r vector-raster, fig.height = 3}
vector_text_raster("Hello", "gridfont_smooth") |>
  plot(interpolate = FALSE)
```

## Vector font: Bespoke pixel rendering

This is an example of bespoke rendering of the strokes for an example string.

For each character (`char_idx`) there are 1-or-more strokes (`stroke`).  Each stroke
has at least 2 points (indicated by `idx`).

When plotting with ggplot, draw path for the points-within-strokes-within-characters.


```{r vector-bespoke, fig.height = 3}
library(ggplot2)

coords <- vector_text_coords("Hello", "gridfont_smooth")
head(coords)

ggplot(coords) +
  geom_path(aes(x, y, 
                group = interaction(char_idx, stroke_idx), 
                colour = as.factor(char_idx)), 
            linewidth = 4) +
  geom_point(aes(x, y), color = 'yellow') + 
  theme_bw() + 
  theme(legend.position = 'none')
```