max7219-display 0.1.5

//! Font definitions for use with 8x8 LED matrix displays.

/// 8x8 font mapping for LED matrix displays
#[derive(Copy, Clone)]
pub struct LedFont {
    char_map: &'static [([u8; 8], char)],
}

impl LedFont {
    /// Create a new font
    pub const fn new(char_map: &'static [([u8; 8], char)]) -> Self {
        Self { char_map }
    }

    /// Get bitmap pattern for a character
    pub fn get_char(&self, ch: char) -> [u8; 8] {
        for &(bitmap, c) in self.char_map {
            if c == ch {
                return bitmap;
            }
        }
        FONT8X8_UNKNOWN
    }
}

/// Standard font for 8x8 LED matrix
pub const STANDARD_LED_FONT: LedFont = LedFont::new(FONT8X8);

/// Fallback 8x8 glyph used when a character is not found in the font map.
///
/// This pattern resembles a question mark and is shown for unsupported or unknown characters.
///
/// Each byte represents one row in the 8x8 grid, with bits set to 1 for lit pixels.
pub const FONT8X8_UNKNOWN: [u8; 8] = [
    // Question mark : ?
    0b00000000, 0b00111100, 0b01000010, 0b00000010, 0b00001100, 0b00000000, 0b00001100, 0b00000000,
];

/// A simple 8x8 font map, with bit-reversed (corrected) glyphs to fix mirroring
#[rustfmt::skip]
pub const FONT8X8: &[([u8; 8], char)] = &[
    (
        [
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        ' ',
    ), // (space)
    (
        [
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00000000,
            0b00011000,
            0b00000000,
        ],
        '!',
    ),
    (
        [
            0b01101100,
            0b01101100,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '"',
    ),
    (
        [
            0b01101100,
            0b01101100,
            0b11111110,
            0b01101100,
            0b11111110,
            0b01101100,
            0b01101100,
            0b00000000,
        ],
        '#',
    ),
    (
        [
            0b00011000,
            0b00111110,
            0b01100000,
            0b00111100,
            0b00000110,
            0b01111100,
            0b00011000,
            0b00000000,
        ],
        '$',
    ),
    (
        [
            0b01100010,
            0b01100100,
            0b00001000,
            0b00010000,
            0b00100000,
            0b01000110,
            0b10000110,
            0b00000000,
        ],
        '%',
    ),
    (
        [
            0b00111000,
            0b01101100,
            0b00111000,
            0b01110110,
            0b11011100,
            0b11001100,
            0b01110110,
            0b00000000,
        ],
        '&',
    ),
    (
        [
            0b00011000,
            0b00011000,
            0b00010000,
            0b00100000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '\'',
    ),
    (
        [
            0b00001100,
            0b00011000,
            0b00110000,
            0b00110000,
            0b00110000,
            0b00011000,
            0b00001100,
            0b00000000,
        ],
        '(',
    ),
    (
        [
            0b00110000,
            0b00011000,
            0b00001100,
            0b00001100,
            0b00001100,
            0b00011000,
            0b00110000,
            0b00000000,
        ],
        ')',
    ),
    (
        [
            0b00000000,
            0b01100110,
            0b00111100,
            0b01111110,
            0b00111100,
            0b01100110,
            0b00000000,
            0b00000000,
        ],
        '*',
    ),
    (
        [
            0b00000000,
            0b00011000,
            0b00011000,
            0b01111110,
            0b00011000,
            0b00011000,
            0b00000000,
            0b00000000,
        ],
        '+',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00011000,
            0b00011000,
            0b00010000,
            0b00100000,
        ],
        ',',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b00000000,
            0b01111110,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '-',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00011000,
            0b00011000,
            0b00000000,
        ],
        '.',
    ),
    (
        [
            0b00000010,
            0b00000110,
            0b00001100,
            0b00011000,
            0b00110000,
            0b01100000,
            0b01000000,
            0b00000000,
        ],
        '/',
    ),
      (
        [
            0b00111100,
            0b01100110,
            0b01101110,
            0b01110110,
            0b01100110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '0',
    ),
    (
        [
            0b00011000,
            0b00111000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b01111110,
            0b00000000,
        ],
        '1',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b00000110,
            0b00001100,
            0b00110000,
            0b01100000,
            0b01111110,
            0b00000000,
        ],
        '2',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b00000110,
            0b00011100,
            0b00000110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '3',
    ),
    (
        [
            0b00001100,
            0b00011100,
            0b00111100,
            0b01101100,
            0b01111110,
            0b00001100,
            0b00011110,
            0b00000000,
        ],
        '4',
    ),
    (
        [
            0b01111110,
            0b01100000,
            0b01111100,
            0b00000110,
            0b00000110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '5',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b01100000,
            0b01111100,
            0b01100110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '6',
    ),
    (
        [
            0b01111110,
            0b01100110,
            0b00000110,
            0b00001100,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00000000,
        ],
        '7',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b01100110,
            0b00111100,
            0b01100110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '8',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b01100110,
            0b00111110,
            0b00000110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        '9',
    ),
    (
        [
            0b00000000,
            0b00011000,
            0b00011000,
            0b00000000,
            0b00011000,
            0b00011000,
            0b00000000,
            0b00000000,
        ],
        ':',
    ),
    (
        [
            0b00000000,
            0b00011000,
            0b00011000,
            0b00000000,
            0b00011000,
            0b00010000,
            0b00100000,
            0b00000000,
        ],
        ';',
    ),
    (
        [
            0b00000110,
            0b00001100,
            0b00011000,
            0b00110000,
            0b00011000,
            0b00001100,
            0b00000110,
            0b00000000,
        ],
        '<',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01111110,
            0b00000000,
            0b01111110,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '=',
    ),
    (
        [
            0b01100000,
            0b00110000,
            0b00011000,
            0b00001100,
            0b00011000,
            0b00110000,
            0b01100000,
            0b00000000,
        ],
        '>',
    ),
    (
        [
            0b00111100,
            0b01100110,
            0b00000110,
            0b00001100,
            0b00011000,
            0b00000000,
            0b00011000,
            0b00000000,
        ],
        '?',
    ),
    (
        [
            0b01111100,
            0b11001100,
            0b11011110,
            0b11011110,
            0b11011110,
            0b11000000,
            0b01111100,
            0b00000000,
        ],
        '@',
    ),
    (
        [
            0b00011000,
            0b00111100,
            0b01100110,
            0b01100110,
            0b01111110,
            0b01100110,
            0b01100110,
            0b00000000,
        ],
        'A',
    ),
    (
        [
            0b01111100,
            0b00110010,
            0b00110010,
            0b00111100,
            0b00110010,
            0b00110010,
            0b01111100,
            0b00000000,
        ],
        'B',
    ),
    (
        [
            0b00011100,
            0b00100010,
            0b01000000,
            0b01000000,
            0b01000000,
            0b00100010,
            0b00011100,
            0b00000000,
        ],
        'C',
    ),
    (
        [
            0b01111000,
            0b00110100,
            0b00110010,
            0b00110010,
            0b00110010,
            0b00110100,
            0b01111000,
            0b00000000,
        ],
        'D',
    ),
    (
        [
            0b01111110,
            0b00100000,
            0b00100000,
            0b00111100,
            0b00100000,
            0b00100000,
            0b01111110,
            0b00000000,
        ],
        'E',
    ),
    (
        [
            0b01111110,
            0b00110000,
            0b00100000,
            0b00111100,
            0b00100000,
            0b00100000,
            0b01110000,
            0b00000000,
        ],
        'F',
    ),
    (
        [
            0b00011100,
            0b00100010,
            0b01000000,
            0b01001110,
            0b01000010,
            0b00100010,
            0b00011100,
            0b00000000,
        ],
        'G',
    ),
    (
        [
            0b01100110,
            0b01100110,
            0b01100110,
            0b01111110,
            0b01100110,
            0b01100110,
            0b01100110,
            0b00000000,
        ],
        'H',
    ),
    (
        [
            0b00111100,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00111100,
            0b00000000,
        ],
        'I',
    ),
    (
        [
            0b00011110,
            0b00001100,
            0b00001100,
            0b00001100,
            0b00001100,
            0b01101100,
            0b00111000,
            0b00000000,
        ],
        'J',
    ),
    (
        [
            0b01100011,
            0b01100110,
            0b01101100,
            0b01111000,
            0b01101100,
            0b01100110,
            0b01100011,
            0b00000000,
        ],
        'K',
    ),
    (
        [
            0b01110000,
            0b00100000,
            0b00100000,
            0b00100000,
            0b00100000,
            0b00110000,
            0b01111110,
            0b00000000,
        ],
        'L',
    ),
    (
        [
            0b01100011,
            0b01110111,
            0b01111111,
            0b01101011,
            0b01100011,
            0b01100011,
            0b01100011,
            0b00000000,
        ],
        'M',
    ),
    (
        [
            0b01100011,
            0b01110011,
            0b01111011,
            0b01101111,
            0b01100111,
            0b01100011,
            0b01100011,
            0b00000000,
        ],
        'N',
    ),
    (
        [
            0b00011000,
            0b00100100,
            0b01000010,
            0b01000010,
            0b01000010,
            0b00100100,
            0b00011000,
            0b00000000,
        ],
        'O',
    ),
    (
        [
            0b01111100,
            0b00110010,
            0b00110010,
            0b00111100,
            0b00100000,
            0b00100000,
            0b01110000,
            0b00000000,
        ],
        'P',
    ),
    (
        [
            0b00011000,
            0b00100100,
            0b01000010,
            0b01000010,
            0b01001010,
            0b00100100,
            0b00011010,
            0b00000000,
        ],
        'Q',
    ),
    (
        [
            0b01111100,
            0b00110010,
            0b00110010,
            0b00111100,
            0b00110100,
            0b00110110,
            0b01100110,
            0b00000000,
        ],
        'R',
    ),
    (
        [
            0b00111100,
            0b01100010,
            0b01100000,
            0b00111100,
            0b00000110,
            0b01000110,
            0b00111100,
            0b00000000,
        ],
        'S',
    ),
    (
        [
            0b01111110,
            0b01011010,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00111100,
            0b00000000,
        ],
        'T',
    ),
    (
        [
            0b01100110,
            0b01100110,
            0b01100110,
            0b01100110,
            0b01100110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        'U',
    ),
    (
        [
            0b01100110,
            0b01100110,
            0b01100110,
            0b01100110,
            0b00111100,
            0b00011000,
            0b00011000,
            0b00000000,
        ],
        'V',
    ),
    (
        [
            0b01100011,
            0b01100011,
            0b01100011,
            0b01101011,
            0b01111111,
            0b01110111,
            0b01100011,
            0b00000000,
        ],
        'W',
    ),
    (
        [
            0b01100011,
            0b00110110,
            0b00011100,
            0b00001000,
            0b00011100,
            0b00110110,
            0b01100011,
            0b00000000,
        ],
        'X',
    ),
    (
        [
            0b01100011,
            0b00110110,
            0b00011100,
            0b00001000,
            0b00001000,
            0b00001000,
            0b00011100,
            0b00000000,
        ],
        'Y',
    ),
    (
        [
            0b01111110,
            0b00000110,
            0b00001100,
            0b00011000,
            0b00110000,
            0b01100000,
            0b01111110,
            0b00000000,
        ],
        'Z',
    ),
    (
        [
            0b00011100,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011100,
            0b00000000,
        ],
        '[',
    ),
    (
        [
            0b11000000,
            0b01100000,
            0b00110000,
            0b00011000,
            0b00001100,
            0b00000110,
            0b00000011,
            0b00000001,
        ],
        '\\',
    ),
    (
        [
            0b00111000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00111000,
            0b00000000,
        ],
        ']',
    ),
    (
        [
            0b00010000,
            0b00111000,
            0b01101100,
            0b11000110,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '^',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b11111111,
        ],
        '_',
    ),
    (
        [
            0b00010000,
            0b00001000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '`',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01111000,
            0b00001100,
            0b01111100,
            0b11001100,
            0b01110110,
            0b00000000,
        ],
        'a',
    ),
    (
        [
            0b11100000,
            0b01100000,
            0b01100000,
            0b01111100,
            0b01100110,
            0b01100110,
            0b11011100,
            0b00000000,
        ],
        'b',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01111000,
            0b11001100,
            0b11000000,
            0b11001100,
            0b01111000,
            0b00000000,
        ],
        'c',
    ),
    (
        [
            0b00011110,
            0b00001100,
            0b00001100,
            0b01111100,
            0b11001100,
            0b11001100,
            0b01110110,
            0b00000000,
        ],
        'd',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01111000,
            0b11001100,
            0b11111100,
            0b11000000,
            0b01111000,
            0b00000000,
        ],
        'e',
    ),
    (
        [
            0b00011100,
            0b00110000,
            0b00110000,
            0b01111100,
            0b00110000,
            0b00110000,
            0b00110000,
            0b00000000,
        ],
        'f',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01110110,
            0b11001100,
            0b11001100,
            0b01111100,
            0b00001100,
            0b11111000,
        ],
        'g',
    ),
    (
        [
            0b11100000,
            0b01100000,
            0b01101100,
            0b01110110,
            0b01100110,
            0b01100110,
            0b11100110,
            0b00000000,
        ],
        'h',
    ),
    (
        [
            0b00110000,
            0b00000000,
            0b01110000,
            0b00110000,
            0b00110000,
            0b00110000,
            0b01111000,
            0b00000000,
        ],
        'i',
    ),
    (
        [
            0b00000110,
            0b00000000,
            0b00000110,
            0b00000110,
            0b00000110,
            0b01100110,
            0b00111100,
            0b00000000,
        ],
        'j',
    ),
    (
        [
            0b11100000,
            0b01100000,
            0b01101100,
            0b01101100,
            0b01111000,
            0b01101100,
            0b11100110,
            0b00000000,
        ],
        'k',
    ),
    (
        [
            0b01110000,
            0b00110000,
            0b00110000,
            0b00110000,
            0b00110000,
            0b00110000,
            0b01111000,
            0b00000000,
        ],
        'l',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01101100,
            0b11111110,
            0b11011010,
            0b11011010,
            0b11011010,
            0b00000000,
        ],
        'm',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11110000,
            0b11001100,
            0b11001100,
            0b11001100,
            0b11001100,
            0b00000000,
        ],
        'n',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01111000,
            0b11001100,
            0b11001100,
            0b11001100,
            0b01111000,
            0b00000000,
        ],
        'o',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11011100,
            0b01100110,
            0b01100110,
            0b01111100,
            0b01100000,
            0b11110000,
        ],
        'p',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b01110110,
            0b11001100,
            0b11001100,
            0b01111100,
            0b00001100,
            0b00011110,
        ],
        'q',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11011100,
            0b01110110,
            0b01100110,
            0b01100000,
            0b11110000,
            0b00000000,
        ],
        'r',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b00111100,
            0b01100000,
            0b00111100,
            0b00000110,
            0b01111100,
            0b00000000,
        ],
        's',
    ),
    (
        [
            0b00010000,
            0b00010000,
            0b01111100,
            0b00010000,
            0b00010000,
            0b00010000,
            0b00001100,
            0b00000000,
        ],
        't',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11001100,
            0b11001100,
            0b11001100,
            0b11001100,
            0b01110110,
            0b00000000,
        ],
        'u',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11001100,
            0b11001100,
            0b11001100,
            0b01111000,
            0b00110000,
            0b00000000,
        ],
        'v',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11011010,
            0b11011010,
            0b11011010,
            0b11111110,
            0b01101100,
            0b00000000,
        ],
        'w',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11001100,
            0b01111000,
            0b00110000,
            0b01111000,
            0b11001100,
            0b00000000,
        ],
        'x',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11001100,
            0b11001100,
            0b11001100,
            0b01111100,
            0b00001100,
            0b11110000,
        ],
        'y',
    ),
    (
        [
            0b00000000,
            0b00000000,
            0b11111100,
            0b10011000,
            0b00110000,
            0b01100100,
            0b11111100,
            0b00000000,
        ],
        'z',
    ),
    (
        [
            0b00001100,
            0b00011000,
            0b00011000,
            0b01110000,
            0b00011000,
            0b00011000,
            0b00001100,
            0b00000000,
        ],
        '{',
    ),
    (
        [
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00011000,
            0b00000000,
        ],
        '|',
    ),
    (
        [
            0b00110000,
            0b00011000,
            0b00011000,
            0b00001110,
            0b00011000,
            0b00011000,
            0b00110000,
            0b00000000,
        ],
        '}',
    ),
    (
        [
            0b01110110,
            0b11011100,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
            0b00000000,
        ],
        '~',
    ),
];

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_new_font() {
        // Create a minimal font for testing
        const TEST_FONT_DATA: &[([u8; 8], char)] = &[
            (
                [
                    0b00111100, 0b01100110, 0b01101110, 0b01110110, 0b01100110, 0b01100110,
                    0b00111100, 0b00000000,
                ],
                '0',
            ),
            (
                [
                    0b00011000, 0b00111000, 0b00011000, 0b00011000, 0b00011000, 0b00011000,
                    0b01111110, 0b00000000,
                ],
                '1',
            ),
        ];

        let font = LedFont::new(TEST_FONT_DATA);
        assert_eq!(font.char_map, TEST_FONT_DATA);
    }

    #[test]
    fn test_get_char_existing() {
        // Test getting bitmap for existing characters
        let bitmap_0 = STANDARD_LED_FONT.get_char('0');
        let expected_0 = [
            0b00111100, 0b01100110, 0b01101110, 0b01110110, 0b01100110, 0b01100110, 0b00111100,
            0b00000000,
        ];
        assert_eq!(bitmap_0, expected_0);

        let bitmap_a = STANDARD_LED_FONT.get_char('A');
        let expected_a = [
            0b00011000, 0b00111100, 0b01100110, 0b01100110, 0b01111110, 0b01100110, 0b01100110,
            0b00000000,
        ];
        assert_eq!(bitmap_a, expected_a);
    }

    #[test]
    fn test_get_char_missing() {
        // Test getting bitmap for non-existing character
        let bitmap_unknown = STANDARD_LED_FONT.get_char('€');
        assert_eq!(bitmap_unknown, FONT8X8_UNKNOWN);
    }

    #[test]
    fn test_get_char_case_sensitivity() {
        // Test that uppercase and lowercase are different
        let bitmap_upper_a = STANDARD_LED_FONT.get_char('A');
        let bitmap_lower_a = STANDARD_LED_FONT.get_char('a');

        assert_ne!(bitmap_upper_a, bitmap_lower_a);

        let expected_upper_a = [
            0b00011000, 0b00111100, 0b01100110, 0b01100110, 0b01111110, 0b01100110, 0b01100110,
            0b00000000,
        ];

        let expected_lower_a = [
            0b00000000, 0b00000000, 0b01111000, 0b00001100, 0b01111100, 0b11001100, 0b01110110,
            0b00000000,
        ];

        assert_eq!(bitmap_upper_a, expected_upper_a);
        assert_eq!(bitmap_lower_a, expected_lower_a);
    }

    #[test]
    fn test_special_characters() {
        // Test a few special characters to ensure they're in the font
        let space_bitmap = STANDARD_LED_FONT.get_char(' ');
        let expected_space = [
            0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000,
            0b00000000,
        ];
        assert_eq!(space_bitmap, expected_space);

        let exclamation_bitmap = STANDARD_LED_FONT.get_char('!');
        let expected_exclamation = [
            0b00011000, 0b00011000, 0b00011000, 0b00011000, 0b00011000, 0b00000000, 0b00011000,
            0b00000000,
        ];
        assert_eq!(exclamation_bitmap, expected_exclamation);
    }
}