Introduce `RGBAImageWrapper`

[ricott1]

For my use case, it would be nice to be able to get an RGBAImage rather than the RGBImage. If I understand the code structure correctly, this would require a new struct RGBAImageWrapper (and maybe renaming ImageWrapper to RGBImageWrapper) and adding impl Formatter for Image`.

[unrenamed]

Wouldn't a struct like RgbaImageWrapper require an alpha channel, either as an optional or mandatory parameter? This makes the task more complex than it initially seems, as it would require updates to both the API and CLI.

Have you considered converting the RGB image buffer from knossos to an RGBA buffer within your code? Since you're already using the image crate, you could handle the conversion yourself. Something like this:

use image::{RgbImage, RgbaImage, Rgba};

fn convert_rgb_to_rgba(rgb_image: &RgbImage) -> RgbaImage {
    let (width, height) = rgb_image.dimensions();
    let mut rgba_image = RgbaImage::new(width, height);

    for (x, y, rgb_pixel) in rgb_image.enumerate_pixels() {
        let Rgba([r, g, b, _]) = Rgba([rgb_pixel[0], rgb_pixel[1], rgb_pixel[2], 255]);
        rgba_image.put_pixel(x, y, Rgba([r, g, b, 255]));
    }

    rgba_image
}

[ricott1]

Yep, this is what I'm doing now (indeed this feature is not a must have). The RGBA image is slightly nicer in a terminal cause sometimes u want a transparent background.

You do need the alpha channel, but I was thinking that the background builder API could provide a Color::RGBA option.

[unrenamed]

Let's keep this issue open. I'm open to adding new functionality to the library, but I want to do so thoughtfully while keeping it simple.

Meanwhile, issue #11 looks interesting—I’ll take a look at that. An optional seed parameter is something I’d expect from a random generator.