i_slint_core/graphics/
bitmapfont.rs

1// Copyright © SixtyFPS GmbH <info@slint.dev>
2// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
3
4use crate::slice::Slice;
5
6#[repr(C)]
7#[derive(Debug)]
8/// A pre-rendered glyph with the alpha map and associated metrics
9pub struct BitmapGlyph {
10    /// The starting x-coordinate for the glyph, relative to the base line
11    /// This is a fixed point number that is shifted by 6 bits
12    pub x: i16,
13    /// The starting y-coordinate for the glyph, relative to the base line
14    /// This is a fixed point number that is shifted by 6 bits
15    pub y: i16,
16    /// The width of the glyph in pixels
17    pub width: i16,
18    /// The height of the glyph in pixels
19    pub height: i16,
20    /// The horizontal distance to the next glyph
21    /// This is a fixed point number that is shifted by 6 bits
22    pub x_advance: i16,
23    /// The 8-bit alpha map that's to be blended with the current text color
24    /// or 8-bit signed distance field depending on `BitmapFont::sdf`
25    pub data: Slice<'static, u8>,
26}
27
28#[repr(C)]
29#[derive(Debug)]
30/// A set of pre-rendered bitmap glyphs at a fixed pixel size
31pub struct BitmapGlyphs {
32    /// The font size in pixels at which the glyphs were pre-rendered. The boundaries of glyphs may exceed this
33    /// size, if the font designer has chosen so. This is only used for matching.
34    pub pixel_size: i16,
35    /// The data of the pre-rendered glyphs
36    pub glyph_data: Slice<'static, BitmapGlyph>,
37}
38
39#[repr(C)]
40#[derive(Debug)]
41/// An entry in the character map of a [`BitmapFont`].
42pub struct CharacterMapEntry {
43    /// The unicode code point for a given glyph
44    pub code_point: char,
45    /// The corresponding index in the `glyph_data` of [`BitmapGlyphs`]
46    pub glyph_index: u16,
47}
48
49#[repr(C)]
50#[derive(Debug)]
51/// A subset of an originally scalable font that's rendered ahead of time.
52pub struct BitmapFont {
53    /// The family name of the font
54    pub family_name: Slice<'static, u8>,
55    /// A vector of code points and their corresponding glyph index, sorted by code point.
56    pub character_map: Slice<'static, CharacterMapEntry>,
57    /// The font supplied size of the em square.
58    pub units_per_em: f32,
59    /// The font ascent in design metrics (typically positive)
60    pub ascent: f32,
61    /// The font descent in design metrics (typically negative)
62    pub descent: f32,
63    /// The font's x-height.
64    pub x_height: f32,
65    /// The font's cap-height.
66    pub cap_height: f32,
67    /// A vector of pre-rendered glyph sets. Each glyph set must have the same number of glyphs,
68    /// which must be at least as big as the largest glyph index in the character map.
69    pub glyphs: Slice<'static, BitmapGlyphs>,
70    /// The weight of the font in CSS units (400 is normal).
71    pub weight: u16,
72    /// Whether the type-face is rendered italic.
73    pub italic: bool,
74    /// Whether the format of the font is a signed distance field
75    pub sdf: bool,
76}
i_slint_core/graphics/bitmapfont.rs

i_slint_core/graphics/
bitmapfont.rs
