Plan C - Add More Drawings

Plan C - Make Coalcar Optional

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To make the coalcar optional, we need a command-line option for that. We want it to be a boolean (true/false - yes/no), and to default to showing the coalcar.

get_options.rs

...
struct Args {
    /// Move the train '[[z]ip]py', '[f]ast', '[[m]ed]ium', '[s]low' or '[c]rawl'?
    #[arg(short, long, default_value_t = String::from("med"))]
    // The above tells clap that the next line is an argument, that can be entered in as "s" or "speed".
    speed: String,

    /// Fly?
    #[arg(short, long, default_value_t = false)]
    fly: bool,

    /// What Kind of object? D51 | C51 | Little | Jack | Boat | Plane | Twin | Motorcycle
    #[arg(short, long, default_value_t = String::from("D51"))]
    kind: String,

    /// Oops?
    #[arg(short, long, default_value_t = false)]
    oops: bool,
    
    /// Disable eXtra trailing vehicle?
    #[arg(short = 'x', long, default_value_t = false)]
    notail: bool,
    
} // end of Args definitions
...

pub fn parse_opts() -> (u64, bool, String, bool, String, String, bool) {

We don't need to do any processing of the variable within the "parse_opts()" function, other than to return the value to the "main()" function:

get_options.rs

...
       _ => {
            // If none of them match, then ...
            println!("Invalid input; run program with '--help' option for more information. You entered '{}', so the default of 'd51' was used.", switches.kind);
            (String::from("D51"), D51.to_string(), COALCAR.to_string())
        }
    };

    return (speed, switches.fly, kind, switches.oops, image_string, tail, switches.notail);
} // end of parse_opts()
...

And then in "main()", we need to recieve that option, and make a decision based on it:

get_options.rs

n main() {
    // Get the program options from the command-line, if any.
    let (speed, fly, kind, oops, image_string, tail_string, notail) = parse_opts();

    // Convert image_string to a vector of String vectors
    let mut image_vecvec = string_to_stringvecvec(&image_string);

    // If we have a tail for the main image, such as a coalcar, do likewise to it, and then stitch the two images together.
    if tail_string != "".to_string() && !notail {
        let tail_vecvec = string_to_stringvecvec(&tail_string);
        image_vecvec = stitch_tail_to_body(image_vecvec, tail_vecvec);
    }
    // Animate the resulting image vector.
    draw_image(speed, fly, kind, oops, image_vecvec);
} // end of main()

So, if the "tail_string" is not a blank, empty string, meaning there is no coalcar (or other trailing tailpiece), and if the "notail" switch is not set, then process the tail; otherwise, don't. You can test it with:

$ cargo run -- --kind=d51 --notail

or something like

$ cargo run -- -kc -sf -x

Now we can chug along and Add the Accident Mode.