Struct Font 

pub struct Font {
    pub lookup_table: &'static [GlyphEntry],
    pub data: &'static [u8],
    pub ascii_begin: u32,
    pub ascii_end: u32,
    pub max_height: u8,
    pub proportional_width: bool,
}

A bitmap font definition.

Contains all data needed to render text: glyph lookup table, bitmap data, and metadata about the font.

Fields

• lookup_table: Array of glyph entries, one per character in the supported range
• data: Raw bitmap data for all glyphs, packed as bits
• ascii_begin: First character code in the supported range (e.g., 32 for space)
• ascii_end: Last character code in the supported range (e.g., 126 for tilde)
• max_height: Height of all glyphs in pixels
• proportional_width: Whether glyphs have variable widths (vs fixed-width)

Examples

let font = Font::new(
    &LOOKUP_TABLE,    // &[GlyphEntry]
    &FONT_DATA,       // &[u8]
    32,               // ASCII start
    126,              // ASCII end
    8,                // Height
    true,             // Proportional
);

Fields

lookup_table: &'static [GlyphEntry]

Lookup table mapping characters to glyph metadata.

data: &'static [u8]

Packed bitmap data for all glyphs.

ascii_begin: u32

First character code supported by this font.

ascii_end: u32

Last character code supported by this font.

max_height: u8

Maximum height of glyphs in this font (in pixels).

proportional_width: bool

Whether this font uses proportional widths (vs monospace).

Implementations

impl Font

pub const fn new( lookup_table: &'static [GlyphEntry], data: &'static [u8], ascii_begin: u32, ascii_end: u32, max_height: u8, proportional_width: bool, ) -> Self

Create a new font definition.

Arguments

• lookup_table - Array of glyph entries, one per supported character
• data - Raw bitmap data for all glyphs
• ascii_begin - First supported character code
• ascii_end - Last supported character code (inclusive)
• max_height - Height of all glyphs in pixels
• proportional_width - Whether glyphs have variable widths

Examples

let font = Font::new(
    &GLYPHS,      // 95 entries for ASCII 32-126
    &FONT_DATA,   // Binary bitmap data
    32,           // Space
    126,          // Tilde
    8,            // 8-pixel height
    false,        // Monospace
);

pub fn get_glyph(&self, c: char) -> Option<&GlyphEntry>

Get the glyph metadata for a character.

Returns None if the character is not supported by this font.

pub fn glyph_data(&self, entry: &GlyphEntry) -> &[u8]

Get the bitmap data for a glyph.

Data is stored as packed bits: 8 bits per byte, where each set bit represents a pixel that should be drawn.

pub fn measure_str(&self, text: &str, tracking: i32) -> u32

Measure the pixel width of a text string.

Returns the total width including any unsupported characters (which contribute 0 width) and the specified tracking value.

Arguments

• text - The string to measure
• tracking - Extra spacing to add between characters in pixels

Examples

let width = font.measure_str("Hello", 0);      // No extra spacing
let width = font.measure_str("Hello", 2);      // 2 pixels between chars