azul-text-layout

General crate for text layout / text shaping

Example

use azul_text_layout::{
    text_layout::{split_text_into_words, words_to_scaled_words},
    text_shaping::get_font_metrics_freetype,
};

let text = "hello";
let font_size = 14.0; // px
let font = include_bytes!("Helvetica.ttf");
let font_index = 0; // only for fonts with font collections
let font_metrics = get_font_metrics_freetype(&font, font_index);
let words = split_text_into_words(text);
let scaled_words = words_to_scaled_words(&words, &font, font_index as u32, font_metrics, font_size);

let total_width = scaled_words.items.iter().map(|i| i.word_width).sum();

Full text layout

use azul_text_layout::{text_layout, text_shaping::get_font_metrics_freetype};
use azul_css::{LayoutSize, StyleTextAlignmentHorz};
use azul_core::ui_solver::ResolvedTextLayoutOptions;

// set all options of the text
let text = "hello";
let font_size = 14.0; // px
let font_bytes = include_bytes!("Helvetica.ttf");
let font_index = 0; // only for fonts with font collections
let text_layout_options = ResolvedTextLayoutOptions {
    font_size_px: font_size,
    line_height: None,
    letter_spacing: None,
    word_spacing: None,
    tab_width: None,
    // for line breaking, maximum width that a line can have
    max_horizontal_width: Some(400.0), // px
    leading: None,
    holes: Vec::new(),
};

// Cache the font metrics of the given font (baseline, height, etc.)
let font_metrics = get_font_metrics_freetype(font_bytes, font_index as i32);
// "Hello World" => ["Hello", "World"]
let words = text_layout::split_text_into_words(text);
// "Hello" @ 14px => Size { width: 50px, height: 14px }
let scaled_words = text_layout::words_to_scaled_words(&words, font_bytes, font_index, font_metrics, text_layout_options.font_size_px);
// Calculate the origin of the word relative to the line
let word_positions = text_layout::position_words(&words, &scaled_words, &text_layout_options);
// Calculate the origin of the line relative to (0, 0)
let mut inline_text_layout = text_layout::word_positions_to_inline_text_layout(&word_positions, &scaled_words);
// Align the line horizontally
inline_text_layout.align_children_horizontal(StyleTextAlignmentHorz::Center);
// Calculate the glyph positons (line_offset + word_offset + glyph_offset)
let layouted_glyphs = text_layout::get_layouted_glyphs(&word_positions, &scaled_words, &inline_text_layout);

println!("{:#?}", inline_text_layout); // get infos about word offset, line breaking, etc.
println!("{:#?}", layouted_glyphs); // get the final glyph positions relative to the origin

License: MIT