classpad-image 0.1.0

//! Image converter for the Casio fx-CP400 calculator.
//!
//! Provides functions to convert an image with a common format (PNG, JPG, WEBP, BMP) into a C2P file, or multiple image files into a C2B animation file.
//! Also provides functions to convert C2P and C2B files back into more common formats.

use image::{GenericImageView, Pixel};
use std::error::Error;

/// The largest possible image width on the fx-CP400.
/// MAX_IMAGE_WIDTH is equal to 310 (0x136).
pub const MAX_IMAGE_WIDTH: u32 = 0x136; // 310

/// The largest possible image height on the fx-CP400.
/// MAX_IMAGE_HEIGHT is equal to 401 (0x191).
pub const MAX_IMAGE_HEIGHT: u32 = 0x191; // 401

/// Function to convert an image to C2B.
///
/// Takes two arguments: a vector of image paths, which must point to valid image files with PNG, JPG, WEBP or BMP format.
/// At least two images must be supplied.
/// The second argument is the destination of the C2B file.
///
/// Example:
/// ```
/// let paths: Vec<String> = vec![String::from("path/to/file1.png"), String::from("path/to/file2.png")];
/// convert_img_to_c2b(paths, String::from("path/to/destination.c2b")).unwrap();
/// ```
pub fn convert_img_to_c2b(
    image_paths: Vec<String>,
    destination: String,
) -> Result<(), Box<dyn Error>> {
    if image_paths.len() < 2 {
        eprintln!("At least two images have to be supplied!");
        return Ok(());
    }

    let image = image::ImageReader::open(image_paths[0].clone())
        .expect("Failed to open image!")
        .decode()
        .expect("Failed to decode image!");
    let (mut width, mut height): (u32, u32) = (image.width(), image.height());
    (width, height) = fit_image_dimensions(width, height);
    assert!(width > 0 && height > 0);

    let mut images_data: Vec<u8> = Vec::new();
    for path in &image_paths {
        let image = image::ImageReader::open(path)
            .expect("Failed to open image!")
            .decode()
            .expect("Failed to decode image!");
        let (i_width, i_height): (u32, u32) = (image.width(), image.height());
        assert!(i_width > 0 && i_height > 0);

        let image = if i_width > MAX_IMAGE_WIDTH || i_height > MAX_IMAGE_HEIGHT {
            eprintln!("Image too big! scaling down...");
            image.resize(width, height, image::imageops::FilterType::Lanczos3)
        } else {
            image
        };

        let img_data = bitmap_to_rgb565_data(image.clone());
        let compressed_img_data = compress(img_data);

        // Segment length
        let f = compressed_img_data.len();
        let f4 = f >> 24 & 0xFF;
        let f3 = f >> 16 & 0xFF;
        let f2 = f >> 8 & 0xFF;
        let f1 = f & 0xFF;

        images_data.extend_from_slice(&[f4 as u8, f3 as u8, f2 as u8, f1 as u8]);
        images_data.extend_from_slice(&compressed_img_data);
    }
    let header = &get_c2b_header(
        images_data.len(),
        image_paths.len(),
        width as usize,
        height as usize,
    );
    let footer = &get_c2b_footer();
    let mut new_file: Vec<u8> = Vec::new();

    new_file.extend_from_slice(header);
    new_file.extend_from_slice(&images_data);
    new_file.extend_from_slice(footer);
    std::fs::write(destination, new_file)?;

    Ok(())
}

/// Function to convert an image to C2P.
///
/// Takes two arguments: an image path, which must point to a valid image file with PNG, JPG, WEBP or BMP format.
/// The second argument is the destination of the C2P file.
///
/// Example:
/// ```
/// let path: &str = "path/to/file.png";
/// convert_img_to_c2p(path, String::from("path/to/destination.c2p")).unwrap();
/// ```
pub fn convert_img_to_c2p(image_path: &str, destination: String) -> Result<(), Box<dyn Error>> {
    let image = image::ImageReader::open(image_path)
        .expect("Failed to open image!")
        .decode()
        .expect("Failed to decode image!");
    let (width, height): (u32, u32) = fit_image_dimensions(image.width(), image.height());
    assert!(width > 0 && height > 0);

    let image = if width > MAX_IMAGE_WIDTH || height > MAX_IMAGE_HEIGHT {
        eprintln!("Image too big! scaling down...");
        let (new_width, new_height) = (
            (width / (width / MAX_IMAGE_WIDTH)).clamp(1, MAX_IMAGE_WIDTH),
            (height / (height / MAX_IMAGE_HEIGHT)).clamp(1, MAX_IMAGE_HEIGHT),
        );
        image.resize(new_width, new_height, image::imageops::FilterType::Lanczos3)
    } else {
        image
    };

    let img_data = bitmap_to_rgb565_data(image.clone());
    let compressed_img_data = compress(img_data);

    let header = &get_c2p_header(
        compressed_img_data.len(),
        image.width() as usize,
        image.height() as usize,
    );

    let footer = &get_c2p_footer();

    let mut new_file = Vec::new();
    new_file.extend_from_slice(header);
    new_file.extend_from_slice(&compressed_img_data);
    new_file.extend_from_slice(footer);

    std::fs::write(destination, new_file)?;

    Ok(())
}

/// Function to convert a C2P image into a normal image file.
///
/// Takes two arguments: an image path, which must point to a valid C2P image.
/// The second argument is the destination of the converted image file.
///
/// Example:
/// ```
/// let path: &str = "path/to/file.c2p";
/// convert_c2p_to_img(path, String::from("path/to/destination.png")).unwrap();
/// ```
pub fn convert_c2p_to_img(c2p_path: &str, destination: String) -> Result<(), Box<dyn Error>> {
    let c2p_data: Vec<u8> = std::fs::read(c2p_path)?;
    let (header, slice) = c2p_data.split_at(0xDC);
    let (compressed_data, _footer) = slice.split_at(slice.len() - 0x17C);

    let (width, height): (u32, u32) = (
        ((header[0xC2] as u32) << 8) + header[0xC3] as u32,
        ((header[0xC4] as u32) << 8) + header[0xC5] as u32,
    );

    let bytes = miniz_oxide::inflate::decompress_to_vec_zlib(compressed_data)
        .expect("Failed to decompress compressed c2p image data!");

    let mut img_buffer = image::RgbImage::new(width, height);

    let (mut x, mut y) = (0, 0);
    for i in (0..bytes.len()).step_by(2) {
        let pixel = img_buffer.get_pixel_mut(x, y);

        let rgb565: u32 = ((bytes[i] as u32) << 8) + bytes[i + 1] as u32;

        let r5 = rgb565 >> 11;
        let g6 = (rgb565 >> 5) & 0b111111;
        let b5 = rgb565 & 0b11111;

        let r = (r5 as f32 / 31.0 * 255.0) as u8;
        let g = (g6 as f32 / 63.0 * 255.0) as u8;
        let b = (b5 as f32 / 31.0 * 255.0) as u8;

        *pixel = image::Rgb::from([r, g, b]);

        x += 1;
        if x == img_buffer.width() {
            x = 0;
            y += 1
        }
    }

    img_buffer.save(destination)?;
    Ok(())
}

/// Function to convert a C2B image into a group of normal image file.
///
/// Takes two arguments: an image path, which must point to a valid C2B image.
/// The second argument is the destination of the converted image files.
/// All images following the first will be named after the first with their respective index.
///
/// Example:
/// ```
/// let path: &str = "path/to/file.c2b";
/// convert_c2p_to_img(path, String::from("path/to/destination.png")).unwrap();
/// ```
pub fn convert_c2b_to_imgs(c2b_path: &str, destination: String) -> Result<(), Box<dyn Error>> {
    let c2b_data: Vec<u8> = std::fs::read(c2b_path)?;
    let (header, data) = c2b_data.split_at(0xD8);

    let (width, height): (u32, u32) = (
        ((header[0xC2] as u32) << 8) + header[0xC3] as u32,
        ((header[0xC4] as u32) << 8) + header[0xC5] as u32,
    );

    let mut image_block_len = (((data[0x00] as u32) << 24)
        + ((data[0x01] as u32) << 16)
        + ((data[0x02] as u32) << 8)
        + (data[0x03] as u32)) as usize;
    let mut offset: usize = 0x04;
    let mut index: usize = 0;

    while data[offset] == 0x78 && data[offset + 1] == 0x9C {
        let (mut x, mut y) = (0, 0);
        let mut img_buffer = image::RgbImage::new(width, height);
        let data_buffer = &data[offset..offset + image_block_len];
        let bytes = miniz_oxide::inflate::decompress_to_vec_zlib(data_buffer)
            .expect("Failed to decompress compressed c2p image data!");

        for i in (0..bytes.len()).step_by(2) {
            let pixel = img_buffer.get_pixel_mut(x, y);

            let rgb565: u32 = ((bytes[i] as u32) << 8) + bytes[i + 1] as u32;

            let r5 = rgb565 >> 11;
            let g6 = (rgb565 >> 5) & 0b111111;
            let b5 = rgb565 & 0b11111;

            let r = (r5 as f32 / 31.0 * 255.0) as u8;
            let g = (g6 as f32 / 63.0 * 255.0) as u8;
            let b = (b5 as f32 / 31.0 * 255.0) as u8;

            *pixel = image::Rgb::from([r, g, b]);

            x += 1;
            if x == img_buffer.width() {
                x = 0;
                y += 1
            }
        }

        let tmp = image_block_len;
        image_block_len = (((data[offset + image_block_len + 0x00] as u32) << 24)
            + ((data[offset + image_block_len + 0x01] as u32) << 16)
            + ((data[offset + image_block_len + 0x02] as u32) << 8)
            + (data[offset + image_block_len + 0x03] as u32)) as usize;
        offset += tmp + 4;

        let (file_dest, ext) = destination.rsplit_once('.').unwrap();
        let destination = format!("{file_dest}{index}.{ext}");
        index += 1;

        img_buffer.save(&destination)?;
    }

    Ok(())
}

/// Function to scale the initial image dimensions to fit into the maximum image scale.
fn fit_image_dimensions(width: u32, height: u32) -> (u32, u32) {
    let (mut new_width, mut new_height) = (width, height);

    if width > MAX_IMAGE_WIDTH || height > MAX_IMAGE_HEIGHT {
        eprintln!("Image too big! scaling down...");
        if width < height {
            let aspect_ratio: f32 = width as f32 / height as f32;
            new_height = MAX_IMAGE_HEIGHT;
            new_width = (aspect_ratio * new_height as f32) as u32;
        } else {
            let aspect_ratio: f32 = height as f32 / width as f32;
            new_width = MAX_IMAGE_WIDTH;
            new_height = (aspect_ratio * new_width as f32) as u32;
        }

        eprintln!("New size: {} x {}", new_width, new_height);
    }

    (new_width, new_height)
}

/// Function to convert the color data of the image into the RGB565 color format.
fn bitmap_to_rgb565_data(image: image::DynamicImage) -> Vec<u8> {
    let mut image_data = Vec::new();

    for y in 0..image.height() {
        for x in 0..image.width() {
            let c = image.get_pixel(x, y).to_rgb().0;

            let (r, g, b) = (
                convert_range(0, 255, 0, 0x1F, c[0] as usize),
                convert_range(0, 255, 0, 0x3F, c[1] as usize),
                convert_range(0, 255, 0, 0x1F, c[2] as usize),
            );

            let rgb565: usize = (r << 11) + (g << 5) + b;
            let rgb565_2: u8 = (rgb565 >> 8 & 0xFF) as u8;
            let rgb565_1: u8 = (rgb565 & 0xFF) as u8;

            image_data.push(rgb565_2);
            image_data.push(rgb565_1);
        }
    }
    image_data
}

/// Function that converts the given range to correctly display the bytes.
fn convert_range(
    original_start: usize,
    original_end: usize,
    new_start: usize,
    new_end: usize,
    value: usize,
) -> usize {
    let scale: f64 = (new_end - new_start) as f64 / (original_end - original_start) as f64;
    (new_start as f64 + ((value - original_start) as f64 * scale)) as usize
}

/// Compresses the given image data with the default zlib compression.
fn compress(input: Vec<u8>) -> Vec<u8> {
    miniz_oxide::deflate::compress_to_vec_zlib(&input, 6)
}

/// Function that returns the C2P file header, with certain bytes changed depending on the file size.
fn get_c2p_header(image_data_size: usize, width: usize, height: usize) -> Vec<u8> {
    let file_size: usize = image_data_size + 0xDC + 0x17C; // image size + header size + footer size
    let a = !(file_size & 0xFFFFFF) & 0xFFFFFF;
    let a3 = (a >> 16 & 0xFF) as u8;
    let a2 = (a >> 8 & 0xFF) as u8;
    let a1 = (a & 0xFF) as u8;

    let b1 = ((0x1D1 - (file_size & 0xFF)) & 0xFF) as u8;

    let c = file_size - 0x20;
    let c4 = (c >> 24 & 0xFF) as u8;
    let c3 = (c >> 16 & 0xFF) as u8;
    let c2 = (c >> 8 & 0xFF) as u8;
    let c1 = (c & 0xFF) as u8;

    let d = file_size - 0x234;
    let d4 = (d >> 24 & 0xFF) as u8;
    let d3 = (d >> 16 & 0xFF) as u8;
    let d2 = (d >> 8 & 0xFF) as u8;
    let d1 = (d & 0xFF) as u8;

    let e = file_size - 0x254;
    let e4 = (e >> 24 & 0xFF) as u8;
    let e3 = (e >> 16 & 0xFF) as u8;
    let e2 = (e >> 8 & 0xFF) as u8;
    let e1 = (e & 0xFF) as u8;

    let w = width & 0xFFFF;
    let h = height & 0xFFFF;
    let w2 = (w >> 8 & 0xFF) as u8;
    let w1 = (w & 0xFF) as u8;
    let h2 = (h >> 8 & 0xFF) as u8;
    let h1 = (h & 0xFF) as u8;

    let f = file_size - 0x258;
    let f4 = (f >> 24 & 0xFF) as u8;
    let f3 = (f >> 16 & 0xFF) as u8;
    let f2 = (f >> 8 & 0xFF) as u8;
    let f1 = (f & 0xFF) as u8;

    vec![
        0xBC, 0xBE, 0xAC, 0xB6, 0xB0, 0xFF, 0xFF, 0xFF, 0x9C, 0xCD, 0x8F, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFE, 0xFF, 0xEF, 0xFF, 0xFE, 0xFF, a3, a2, a1, b1, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x43, 0x43, 0x30, 0x31, 0x30, 0x30, 0x43, 0x6F, 0x6C, 0x6F, 0x72, 0x43, 0x50, 0x00,
        0x00, 0x00, c4, c3, c2, c1, 0x00, 0x00, 0x00, 0x09, d4, d3, d2, d1, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x7C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x30, 0x31, 0x30, 0x30, e4, e3, e2, e1, 0x00, 0x00, w2, w1, h2, h1, 0x00, 0x10, 0x00, 0xFF,
        0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x01, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, f4, f3,
        f2, f1,
    ]
}

/// Function that returns the C2P footer.
/// This is the same for all C2P files.
fn get_c2p_footer() -> Vec<u8> {
    vec![
        0x30, 0x31, 0x30, 0x30, 0x00, 0x00, 0x00, 0x8C, 0x07, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x60, 0x00, 0x07, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x05,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x09, 0x98, 0x04, 0x60, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x04, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x10, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x09, 0x98, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x28, 0x31, 0x85,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x06, 0x28, 0x32, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x09, 0x98, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x30, 0x31,
        0x30, 0x30, 0xE0, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
        0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x02, 0x50, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
        0x02, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x02, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01,
        0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x07, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00,
        0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x01, 0x01,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
    ]
}

/// Function that returns the C2B file header, with certain bytes changed depending on the file size.
fn get_c2b_header(
    image_data_size: usize,
    total_image_count: usize,
    width: usize,
    height: usize,
) -> Vec<u8> {
    let file_size: usize = image_data_size + 0xD8 + 0x1A8; // image size + header size + footer size
    let a = !(file_size & 0xFFFFFF) & 0xFFFFFF;
    let a3 = (a >> 16 & 0xFF) as u8;
    let a2 = (a >> 8 & 0xFF) as u8;
    let a1 = (a & 0xFF) as u8;

    let b1 = ((0x1D0 - (file_size & 0xFF)) & 0xFF) as u8;

    let c = file_size - 0x20;
    let c4 = (c >> 24 & 0xFF) as u8;
    let c3 = (c >> 16 & 0xFF) as u8;
    let c2 = (c >> 8 & 0xFF) as u8;
    let c1 = (c & 0xFF) as u8;

    let d = file_size - 0x260;
    let d4 = (d >> 24 & 0xFF) as u8;
    let d3 = (d >> 16 & 0xFF) as u8;
    let d2 = (d >> 8 & 0xFF) as u8;
    let d1 = (d & 0xFF) as u8;

    let e = file_size - 0x280;
    let e4 = (e >> 24 & 0xFF) as u8;
    let e3 = (e >> 16 & 0xFF) as u8;
    let e2 = (e >> 8 & 0xFF) as u8;
    let e1 = (e & 0xFF) as u8;

    let w = width & 0xFFFF;
    let h = height & 0xFFFF;
    let w2 = (w >> 8 & 0xFF) as u8;
    let w1 = (w & 0xFF) as u8;
    let h2 = (h >> 8 & 0xFF) as u8;
    let h1 = (h & 0xFF) as u8;

    let i = total_image_count as u8;

    vec![
        0xBC, 0xBE, 0xAC, 0xB6, 0xB0, 0xFF, 0xFF, 0xFF, 0x9C, 0xCD, 0x9D, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFE, 0xFF, 0xEF, 0xFF, 0xFE, 0xFF, a3, a2, a1, b1, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x43, 0x43, 0x30, 0x31, 0x30, 0x30, 0x43, 0x6F, 0x6C, 0x6F, 0x72, 0x43, 0x50, 0x00,
        0x00, 0x00, c4, c3, c2, c1, 0x00, 0x00, 0x00, 0x92, 0x00, 0x00, 0x00, 0x00, d4, d3, d2, d1,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x7C, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x30, 0x31, 0x30, 0x30, e4, e3, e2, e1, 0x00, 0x00, w2, w1, h2, h1, 0x00, 0x10, 0x00, 0xFF,
        0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x01, 0x00, i, 0xFF, 0xFF, 0xFF, 0xFF,
    ]
}

/// Function that returns the C2B footer.
/// Note: this is the same for all files in this program. There are certain bytes that change the size of the window in the 'Picture Plot' program, which are ignored here.
fn get_c2b_footer() -> Vec<u8> {
    vec![
        0x30, 0x31, 0x30, 0x30, 0x00, 0x00, 0x00, 0x8C, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x10, 0x01, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x10, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x03,
        0x24, 0x67, 0x53, 0x24, 0x67, 0x53, 0x25, 0x00, 0x00, 0x09, 0x97, 0x01, 0x02, 0x54, 0x71,
        0x69, 0x81, 0x13, 0x21, 0x00, 0x00, 0x10, 0x01, 0x01, 0x07, 0x45, 0x28, 0x30, 0x18, 0x86,
        0x79, 0x00, 0x00, 0x10, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x10, 0x00, 0x02, 0x35, 0x84, 0x90, 0x56, 0x60, 0x37, 0x74, 0x00, 0x00, 0x09, 0x97, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x28, 0x31, 0x85,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x06, 0x28, 0x32, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x09, 0x98, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x30, 0x31,
        0x30, 0x30, 0xE0, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
        0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x02, 0x50, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
        0x02, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x02, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01,
        0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x07, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x01, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x10, 0x00, 0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00,
        0x03, 0x14, 0x15, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x01, 0x01,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x30, 0x31, 0x30, 0x30, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00,
        0x50, 0x47, 0x54, 0x69, 0x6D, 0x65, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x09, 0x99,
    ]
}