beamterm_data/
atlas.rs

1use std::fmt::Debug;
2
3use compact_str::CompactString;
4
5use crate::{Deserializer, FontAtlasDeserializationError, Glyph, Serializable, SerializationError};
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}"),
66        })
67    }
68
69    /// Serializes the font atlas to binary format.
70    ///
71    /// # Returns
72    /// A byte vector containing the serialized font atlas data, or an error
73    /// if serialization fails (e.g., a string field exceeds 255 bytes)
74    pub fn to_binary(&self) -> Result<Vec<u8>, SerializationError> {
75        self.serialize()
76    }
77
78    /// Calculates how many terminal columns and rows fit in the given viewport dimensions.
79    ///
80    /// # Arguments
81    /// * `viewport_width` - Width of the viewport in pixels
82    /// * `viewport_height` - Height of the viewport in pixels
83    ///
84    /// # Returns
85    /// A tuple of (columns, rows) that fit in the viewport
86    pub fn terminal_size(&self, viewport_width: i32, viewport_height: i32) -> (i32, i32) {
87        (
88            viewport_width / self.cell_size.0,
89            viewport_height / self.cell_size.1,
90        )
91    }
92
93    /// Returns the padded terminal cell size.
94    ///
95    /// The cell size includes padding (1 pixel on each side, 2 pixels total per dimension)
96    /// to prevent texture bleeding artifacts during GPU rendering.
97    ///
98    /// # Returns
99    /// A tuple of (width, height) in pixels for each terminal cell
100    pub fn cell_size(&self) -> (i32, i32) {
101        self.cell_size
102    }
103}
104
105impl Default for FontAtlasData {
106    fn default() -> Self {
107        Self::from_binary(include_bytes!("../atlas/bitmap_font.atlas")).unwrap()
108    }
109}
110
111#[derive(Copy, Clone, Debug, PartialEq)]
112pub struct LineDecoration {
113    /// 0.0 to 1.0, where 0.0 is the top of the text line and 1.0 is the bottom.
114    pub position: f32,
115    /// Thickness of the line as a fraction of the cell height (0.0 to 1.0)
116    pub thickness: f32,
117}
118
119impl LineDecoration {
120    pub fn new(position: f32, thickness: f32) -> Self {
121        Self {
122            position: position.clamp(0.0, 1.0),
123            thickness: thickness.clamp(0.0, 1.0),
124        }
125    }
126}
127
128/// Debug pattern for validating pixel-perfect rendering of cell dimensions.
129///
130/// When enabled, replaces the space glyph with a checkered pattern to help
131/// verify that cell boundaries align correctly with pixel boundaries.
132#[derive(Debug, Clone, Copy, PartialEq, Eq)]
133pub enum DebugSpacePattern {
134    /// 1px alternating checkerboard pattern
135    OnePixel,
136    /// 2x2 pixel checkerboard pattern
137    TwoByTwo,
138}
beamterm_data/atlas.rs

beamterm_data/
atlas.rs
