beamterm_data/
atlas.rs

1use std::fmt::Debug;
2
3use compact_str::CompactString;
4
5use crate::{Deserializer, FontAtlasDeserializationError, Glyph, Serializable};
6
7/// Font atlas data for GPU-accelerated terminal rendering.
8///
9/// Contains a pre-rasterized font atlas stored as a 2D texture array, where each layer
10/// holds 32 glyphs in a 1×32 grid. The atlas includes multiple font styles (normal, bold,
11/// italic, bold+italic) and full Unicode support including emoji.
12#[derive(Clone, PartialEq)]
13pub struct FontAtlasData {
14    /// The name of the font
15    pub font_name: CompactString,
16    /// The font size in points
17    pub font_size: f32,
18    /// The number of single-cell (halfwidth) glyphs per layer, before fullwidth glyphs begin.
19    ///
20    /// Fullwidth glyphs (e.g., CJK characters) are assigned IDs starting from this value,
21    /// aligned to even boundaries. This allows the renderer to distinguish halfwidth from
22    /// fullwidth glyphs by comparing against this threshold.
23    pub max_halfwidth_base_glyph_id: u16,
24    /// Width, height and depth of the texture in pixels
25    pub texture_dimensions: (i32, i32, i32),
26    /// Width and height of each character cell
27    pub cell_size: (i32, i32),
28    /// Underline configuration
29    pub underline: LineDecoration,
30    /// Strikethrough configuration
31    pub strikethrough: LineDecoration,
32    /// The glyphs in the font
33    pub glyphs: Vec<Glyph>,
34    /// The 3d texture data containing the font glyphs
35    pub texture_data: Vec<u8>,
36}
37
38impl Debug for FontAtlasData {
39    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
40        f.debug_struct("FontAtlasData")
41            .field("font_name", &self.font_name)
42            .field("font_size", &self.font_size)
43            .field("texture_dimensions", &self.texture_dimensions)
44            .field("cell_size", &self.cell_size)
45            .field("glyphs_count", &self.glyphs.len())
46            .field("texture_data_kb", &(self.texture_data.len() * 4 / 1024))
47            .finish()
48    }
49}
50
51impl FontAtlasData {
52    pub const PADDING: i32 = 1;
53    pub const CELLS_PER_SLICE: i32 = 32;
54
55    /// Deserializes a font atlas from binary format.
56    ///
57    /// # Arguments
58    /// * `serialized` - Binary data containing the serialized font atlas
59    ///
60    /// # Returns
61    /// The deserialized font atlas or an error if deserialization fails
62    pub fn from_binary(serialized: &[u8]) -> Result<Self, FontAtlasDeserializationError> {
63        let mut deserializer = Deserializer::new(serialized);
64        FontAtlasData::deserialize(&mut deserializer).map_err(|e| FontAtlasDeserializationError {
65            message: format!("Failed to deserialize font atlas: {}", e.message),
66        })
67    }
68
69    /// Serializes the font atlas to binary format.
70    ///
71    /// # Returns
72    /// A byte vector containing the serialized font atlas data
73    pub fn to_binary(&self) -> Vec<u8> {
74        self.serialize()
75    }
76
77    /// Calculates how many terminal columns and rows fit in the given viewport dimensions.
78    ///
79    /// # Arguments
80    /// * `viewport_width` - Width of the viewport in pixels
81    /// * `viewport_height` - Height of the viewport in pixels
82    ///
83    /// # Returns
84    /// A tuple of (columns, rows) that fit in the viewport
85    pub fn terminal_size(&self, viewport_width: i32, viewport_height: i32) -> (i32, i32) {
86        (
87            viewport_width / self.cell_size.0,
88            viewport_height / self.cell_size.1,
89        )
90    }
91
92    /// Returns the padded terminal cell size.
93    ///
94    /// The cell size includes padding (1 pixel on each side, 2 pixels total per dimension)
95    /// to prevent texture bleeding artifacts during GPU rendering.
96    ///
97    /// # Returns
98    /// A tuple of (width, height) in pixels for each terminal cell
99    pub fn cell_size(&self) -> (i32, i32) {
100        self.cell_size
101    }
102}
103
104impl Default for FontAtlasData {
105    fn default() -> Self {
106        Self::from_binary(include_bytes!("../atlas/bitmap_font.atlas")).unwrap()
107    }
108}
109
110#[derive(Copy, Clone, Debug, PartialEq)]
111pub struct LineDecoration {
112    /// 0.0 to 1.0, where 0.0 is the top of the text line and 1.0 is the bottom.
113    pub position: f32,
114    /// Thickness of the line as a fraction of the cell height (0.0 to 1.0)
115    pub thickness: f32,
116}
117
118impl LineDecoration {
119    pub fn new(position: f32, thickness: f32) -> Self {
120        Self {
121            position: position.clamp(0.0, 1.0),
122            thickness: thickness.clamp(0.0, 1.0),
123        }
124    }
125}
126
127/// Debug pattern for validating pixel-perfect rendering of cell dimensions.
128///
129/// When enabled, replaces the space glyph with a checkered pattern to help
130/// verify that cell boundaries align correctly with pixel boundaries.
131#[derive(Debug, Clone, Copy, PartialEq, Eq)]
132pub enum DebugSpacePattern {
133    /// 1px alternating checkerboard pattern
134    OnePixel,
135    /// 2x2 pixel checkerboard pattern
136    TwoByTwo,
137}
beamterm_data/atlas.rs

beamterm_data/
atlas.rs
