Using vector fonts

Vector Fonts: included fonts

names(font_info$vector)

#> [1] "arcade"          "gridfont"        "gridfont_smooth"

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

library(lofifonts)
vector_text_coords("Hello", font = 'gridfont_smooth') |> 
  head()

#> # A tibble: 6 × 11
#>   char_idx codepoint stroke_idx point_idx     x     y  line    x0    y0 width
#>      <int>     <int>      <int>     <int> <dbl> <dbl> <int> <dbl> <dbl> <int>
#> 1        1       104          1         1 0      9        0 0      9        4
#> 2        1       104          1         2 0      3        0 0      3        4
#> 3        1       104          2         1 0      5.67     0 0      5.67     4
#> 4        1       104          2         2 0.167  6.33     0 0.167  6.33     4
#> 5        1       104          2         3 0.667  6.83     0 0.667  6.83     4
#> 6        1       104          2         4 1.17   7        0 1.17   7        4
#> # ℹ 1 more variable: xoffset <int>

vector_text_matrix("Hello", "gridfont_smooth", scale = 1) 

#>       [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
#>  [1,]    1    0    0    0    0    0    0    0    1     1     0     0     0
#>  [2,]    1    0    0    0    0    0    0    0    1     1     0     0     0
#>  [3,]    1    1    1    0    0    1    1    0    1     1     0     1     1
#>  [4,]    1    0    0    1    1    0    0    1    1     1     1     0     0
#>  [5,]    1    0    0    1    1    1    1    1    1     1     1     0     0
#>  [6,]    1    0    0    1    1    0    0    1    1     1     1     0     0
#>  [7,]    1    0    0    0    0    1    1    0    1     1     0     1     1
#>  [8,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#>  [9,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [10,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#>       [,14]
#>  [1,]     0
#>  [2,]     0
#>  [3,]     0
#>  [4,]     1
#>  [5,]     1
#>  [6,]     1
#>  [7,]     0
#>  [8,]     0
#>  [9,]     0
#> [10,]     0

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.

library(ggplot2)

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

#> # A tibble: 6 × 11
#>   char_idx codepoint stroke_idx point_idx     x     y  line    x0    y0 width
#>      <int>     <int>      <int>     <int> <dbl> <dbl> <int> <dbl> <dbl> <int>
#> 1        1       104          1         1 0      9        0 0      9        4
#> 2        1       104          1         2 0      3        0 0      3        4
#> 3        1       104          2         1 0      5.67     0 0      5.67     4
#> 4        1       104          2         2 0.167  6.33     0 0.167  6.33     4
#> 5        1       104          2         3 0.667  6.83     0 0.667  6.83     4
#> 6        1       104          2         4 1.17   7        0 1.17   7        4
#> # ℹ 1 more variable: xoffset <int>

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')