kr580 1.0.0

//! Minimal 5×7 bitmap font for the unified monitor canvas.
//!
//! Covers printable ASCII (`0x20..=0x7E`) – enough to render the text
//! layer over the pixel layer when the monitor is in "unified" view.
//! Each glyph is 5 columns × 7 rows. The glyph rows are MSB-aligned in
//! the lower 5 bits of each byte (bit 4 = leftmost pixel, bit 0 =
//! rightmost). Bytes outside the printable range fall back to a
//! middle-dot glyph so unknown OEM/DOS code points still render.

pub const GLYPH_WIDTH: usize = 5;
pub const GLYPH_HEIGHT: usize = 7;
pub const CELL_WIDTH: usize = 7; // 5 px glyph + 2 px gap
pub const CELL_HEIGHT: usize = 10; // 7 px glyph + 3 px gap

const FALLBACK: [u8; GLYPH_HEIGHT] = [
    0b00000, 0b00000, 0b00000, 0b00100, 0b00000, 0b00000, 0b00000,
];

const TABLE: [(u8, [u8; GLYPH_HEIGHT]); 95] = [
    (0x20, [0, 0, 0, 0, 0, 0, 0]),
    (
        0x21,
        [0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0, 0b00100],
    ), // !
    (0x22, [0b01010, 0b01010, 0, 0, 0, 0, 0]), // "
    (
        0x23,
        [
            0b01010, 0b01010, 0b11111, 0b01010, 0b11111, 0b01010, 0b01010,
        ],
    ), // #
    (
        0x24,
        [
            0b00100, 0b01111, 0b10100, 0b01110, 0b00101, 0b11110, 0b00100,
        ],
    ), // $
    (
        0x25,
        [
            0b11000, 0b11001, 0b00010, 0b00100, 0b01000, 0b10011, 0b00011,
        ],
    ), // %
    (
        0x26,
        [
            0b01100, 0b10010, 0b10100, 0b01000, 0b10101, 0b10010, 0b01101,
        ],
    ), // &
    (0x27, [0b00100, 0b00100, 0, 0, 0, 0, 0]), // '
    (
        0x28,
        [
            0b00010, 0b00100, 0b01000, 0b01000, 0b01000, 0b00100, 0b00010,
        ],
    ), // (
    (
        0x29,
        [
            0b01000, 0b00100, 0b00010, 0b00010, 0b00010, 0b00100, 0b01000,
        ],
    ), // )
    (0x2A, [0, 0b00100, 0b10101, 0b01110, 0b10101, 0b00100, 0]), // *
    (0x2B, [0, 0b00100, 0b00100, 0b11111, 0b00100, 0b00100, 0]), // +
    (0x2C, [0, 0, 0, 0, 0b00100, 0b00100, 0b01000]), // ,
    (0x2D, [0, 0, 0, 0b11111, 0, 0, 0]),       // -
    (0x2E, [0, 0, 0, 0, 0, 0b00100, 0b00100]), // .
    (
        0x2F,
        [
            0b00001, 0b00010, 0b00010, 0b00100, 0b01000, 0b01000, 0b10000,
        ],
    ), // /
    (
        0x30,
        [
            0b01110, 0b10001, 0b10011, 0b10101, 0b11001, 0b10001, 0b01110,
        ],
    ), // 0
    (
        0x31,
        [
            0b00100, 0b01100, 0b00100, 0b00100, 0b00100, 0b00100, 0b01110,
        ],
    ), // 1
    (
        0x32,
        [
            0b01110, 0b10001, 0b00001, 0b00010, 0b00100, 0b01000, 0b11111,
        ],
    ), // 2
    (
        0x33,
        [
            0b11111, 0b00010, 0b00100, 0b00010, 0b00001, 0b10001, 0b01110,
        ],
    ), // 3
    (
        0x34,
        [
            0b00010, 0b00110, 0b01010, 0b10010, 0b11111, 0b00010, 0b00010,
        ],
    ), // 4
    (
        0x35,
        [
            0b11111, 0b10000, 0b11110, 0b00001, 0b00001, 0b10001, 0b01110,
        ],
    ), // 5
    (
        0x36,
        [
            0b00110, 0b01000, 0b10000, 0b11110, 0b10001, 0b10001, 0b01110,
        ],
    ), // 6
    (
        0x37,
        [
            0b11111, 0b00001, 0b00010, 0b00100, 0b01000, 0b01000, 0b01000,
        ],
    ), // 7
    (
        0x38,
        [
            0b01110, 0b10001, 0b10001, 0b01110, 0b10001, 0b10001, 0b01110,
        ],
    ), // 8
    (
        0x39,
        [
            0b01110, 0b10001, 0b10001, 0b01111, 0b00001, 0b00010, 0b01100,
        ],
    ), // 9
    (0x3A, [0, 0b00100, 0b00100, 0, 0b00100, 0b00100, 0]), // :
    (0x3B, [0, 0b00100, 0b00100, 0, 0b00100, 0b00100, 0b01000]), // ;
    (
        0x3C,
        [
            0b00010, 0b00100, 0b01000, 0b10000, 0b01000, 0b00100, 0b00010,
        ],
    ), // <
    (0x3D, [0, 0, 0b11111, 0, 0b11111, 0, 0]), // =
    (
        0x3E,
        [
            0b01000, 0b00100, 0b00010, 0b00001, 0b00010, 0b00100, 0b01000,
        ],
    ), // >
    (
        0x3F,
        [0b01110, 0b10001, 0b00001, 0b00010, 0b00100, 0, 0b00100],
    ), // ?
    (
        0x40,
        [
            0b01110, 0b10001, 0b00001, 0b01101, 0b10101, 0b10101, 0b01110,
        ],
    ), // @
    (
        0x41,
        [
            0b01110, 0b10001, 0b10001, 0b10001, 0b11111, 0b10001, 0b10001,
        ],
    ), // A
    (
        0x42,
        [
            0b11110, 0b10001, 0b10001, 0b11110, 0b10001, 0b10001, 0b11110,
        ],
    ), // B
    (
        0x43,
        [
            0b01110, 0b10001, 0b10000, 0b10000, 0b10000, 0b10001, 0b01110,
        ],
    ), // C
    (
        0x44,
        [
            0b11100, 0b10010, 0b10001, 0b10001, 0b10001, 0b10010, 0b11100,
        ],
    ), // D
    (
        0x45,
        [
            0b11111, 0b10000, 0b10000, 0b11110, 0b10000, 0b10000, 0b11111,
        ],
    ), // E
    (
        0x46,
        [
            0b11111, 0b10000, 0b10000, 0b11110, 0b10000, 0b10000, 0b10000,
        ],
    ), // F
    (
        0x47,
        [
            0b01110, 0b10001, 0b10000, 0b10111, 0b10001, 0b10001, 0b01110,
        ],
    ), // G
    (
        0x48,
        [
            0b10001, 0b10001, 0b10001, 0b11111, 0b10001, 0b10001, 0b10001,
        ],
    ), // H
    (
        0x49,
        [
            0b01110, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b01110,
        ],
    ), // I
    (
        0x4A,
        [
            0b00111, 0b00010, 0b00010, 0b00010, 0b00010, 0b10010, 0b01100,
        ],
    ), // J
    (
        0x4B,
        [
            0b10001, 0b10010, 0b10100, 0b11000, 0b10100, 0b10010, 0b10001,
        ],
    ), // K
    (
        0x4C,
        [
            0b10000, 0b10000, 0b10000, 0b10000, 0b10000, 0b10000, 0b11111,
        ],
    ), // L
    (
        0x4D,
        [
            0b10001, 0b11011, 0b10101, 0b10101, 0b10001, 0b10001, 0b10001,
        ],
    ), // M
    (
        0x4E,
        [
            0b10001, 0b10001, 0b11001, 0b10101, 0b10011, 0b10001, 0b10001,
        ],
    ), // N
    (
        0x4F,
        [
            0b01110, 0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b01110,
        ],
    ), // O
    (
        0x50,
        [
            0b11110, 0b10001, 0b10001, 0b11110, 0b10000, 0b10000, 0b10000,
        ],
    ), // P
    (
        0x51,
        [
            0b01110, 0b10001, 0b10001, 0b10001, 0b10101, 0b10010, 0b01101,
        ],
    ), // Q
    (
        0x52,
        [
            0b11110, 0b10001, 0b10001, 0b11110, 0b10100, 0b10010, 0b10001,
        ],
    ), // R
    (
        0x53,
        [
            0b01111, 0b10000, 0b10000, 0b01110, 0b00001, 0b00001, 0b11110,
        ],
    ), // S
    (
        0x54,
        [
            0b11111, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100,
        ],
    ), // T
    (
        0x55,
        [
            0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b01110,
        ],
    ), // U
    (
        0x56,
        [
            0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b01010, 0b00100,
        ],
    ), // V
    (
        0x57,
        [
            0b10001, 0b10001, 0b10001, 0b10101, 0b10101, 0b10101, 0b01010,
        ],
    ), // W
    (
        0x58,
        [
            0b10001, 0b10001, 0b01010, 0b00100, 0b01010, 0b10001, 0b10001,
        ],
    ), // X
    (
        0x59,
        [
            0b10001, 0b10001, 0b10001, 0b01010, 0b00100, 0b00100, 0b00100,
        ],
    ), // Y
    (
        0x5A,
        [
            0b11111, 0b00001, 0b00010, 0b00100, 0b01000, 0b10000, 0b11111,
        ],
    ), // Z
    (
        0x5B,
        [
            0b01110, 0b01000, 0b01000, 0b01000, 0b01000, 0b01000, 0b01110,
        ],
    ), // [
    (
        0x5C,
        [
            0b10000, 0b01000, 0b01000, 0b00100, 0b00010, 0b00010, 0b00001,
        ],
    ), // backslash
    (
        0x5D,
        [
            0b01110, 0b00010, 0b00010, 0b00010, 0b00010, 0b00010, 0b01110,
        ],
    ), // ]
    (0x5E, [0b00100, 0b01010, 0b10001, 0, 0, 0, 0]), // ^
    (0x5F, [0, 0, 0, 0, 0, 0, 0b11111]),       // _
    (0x60, [0b01000, 0b00100, 0b00010, 0, 0, 0, 0]), // `
    (0x61, [0, 0, 0b01110, 0b00001, 0b01111, 0b10001, 0b01111]), // a
    (
        0x62,
        [
            0b10000, 0b10000, 0b11110, 0b10001, 0b10001, 0b10001, 0b11110,
        ],
    ), // b
    (0x63, [0, 0, 0b01110, 0b10001, 0b10000, 0b10001, 0b01110]), // c
    (
        0x64,
        [
            0b00001, 0b00001, 0b01111, 0b10001, 0b10001, 0b10001, 0b01111,
        ],
    ), // d
    (0x65, [0, 0, 0b01110, 0b10001, 0b11111, 0b10000, 0b01110]), // e
    (
        0x66,
        [
            0b00110, 0b01000, 0b01000, 0b11100, 0b01000, 0b01000, 0b01000,
        ],
    ), // f
    (0x67, [0, 0, 0b01111, 0b10001, 0b01111, 0b00001, 0b01110]), // g
    (
        0x68,
        [
            0b10000, 0b10000, 0b11110, 0b10001, 0b10001, 0b10001, 0b10001,
        ],
    ), // h
    (
        0x69,
        [0b00100, 0, 0b01100, 0b00100, 0b00100, 0b00100, 0b01110],
    ), // i
    (
        0x6A,
        [0b00010, 0, 0b00110, 0b00010, 0b00010, 0b10010, 0b01100],
    ), // j
    (
        0x6B,
        [
            0b10000, 0b10000, 0b10010, 0b10100, 0b11000, 0b10100, 0b10010,
        ],
    ), // k
    (
        0x6C,
        [
            0b01100, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b01110,
        ],
    ), // l
    (0x6D, [0, 0, 0b11010, 0b10101, 0b10101, 0b10101, 0b10001]), // m
    (0x6E, [0, 0, 0b11110, 0b10001, 0b10001, 0b10001, 0b10001]), // n
    (0x6F, [0, 0, 0b01110, 0b10001, 0b10001, 0b10001, 0b01110]), // o
    (0x70, [0, 0, 0b11110, 0b10001, 0b11110, 0b10000, 0b10000]), // p
    (0x71, [0, 0, 0b01111, 0b10001, 0b01111, 0b00001, 0b00001]), // q
    (0x72, [0, 0, 0b10110, 0b11001, 0b10000, 0b10000, 0b10000]), // r
    (0x73, [0, 0, 0b01111, 0b10000, 0b01110, 0b00001, 0b11110]), // s
    (
        0x74,
        [
            0b01000, 0b01000, 0b11100, 0b01000, 0b01000, 0b01000, 0b00110,
        ],
    ), // t
    (0x75, [0, 0, 0b10001, 0b10001, 0b10001, 0b10001, 0b01110]), // u
    (0x76, [0, 0, 0b10001, 0b10001, 0b10001, 0b01010, 0b00100]), // v
    (0x77, [0, 0, 0b10001, 0b10001, 0b10101, 0b10101, 0b01010]), // w
    (0x78, [0, 0, 0b10001, 0b01010, 0b00100, 0b01010, 0b10001]), // x
    (0x79, [0, 0, 0b10001, 0b10001, 0b01111, 0b00001, 0b01110]), // y
    (0x7A, [0, 0, 0b11111, 0b00010, 0b00100, 0b01000, 0b11111]), // z
    (
        0x7B,
        [
            0b00010, 0b00100, 0b00100, 0b01000, 0b00100, 0b00100, 0b00010,
        ],
    ), // {
    (
        0x7C,
        [
            0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100,
        ],
    ), // |
    (
        0x7D,
        [
            0b01000, 0b00100, 0b00100, 0b00010, 0b00100, 0b00100, 0b01000,
        ],
    ), // }
    (0x7E, [0, 0b01001, 0b10110, 0, 0, 0, 0]), // ~
];

pub fn glyph(code: u8) -> [u8; GLYPH_HEIGHT] {
    if code == 0 {
        return [0; GLYPH_HEIGHT];
    }
    for (c, rows) in TABLE.iter() {
        if *c == code {
            return *rows;
        }
    }
    FALLBACK
}

pub fn pixel_lit(code: u8, col: usize, row: usize) -> bool {
    if col >= GLYPH_WIDTH || row >= GLYPH_HEIGHT {
        return false;
    }
    let rows = glyph(code);
    let bit = (GLYPH_WIDTH - 1) - col;
    (rows[row] >> bit) & 1 == 1
}