Simple .ppm loader written in Rust.

This is more of a toy project, I have written, to be able to easy reuse it for some of my experiments with 2d graphics in Rust.

v.0.20.0 Note: This version introduces proper error handling. Earlier tinyppm was a bit of pain as it exited when something unexpected happened (unrecognized header, unsupported color depth, non-existing/unreadable file specified...). Currently tinyppm returns an error in case some problem occurs. It is responsibility of the consumer to decide if this is critical or not, and take appropriate action.

Note: the above change will require some slight modification of code that relies on tinyppm 0.1.x.

1. Add tinyppm to your Cargo.toml
2. Call read_image_data:

extern crate tinyppm;

fn my_function(filename: &String) {
    let ppm_image_result = tinyppm::ppm_loader::read_image_data(filename);
    let ppm_image = match ppm_image_result {
        Ok(image) => image,
        _ => panic!("unable to read specified image file!"),
    };
    // `ppm_image` is now a struct containing image with, height and pixels 
}

The structure returned is defined as follows:

pub struct PPMImage {
    height: usize,
    width: usize,
    pixels: Vec<u32>,
}

and it exposes 3 public methods:

    pub fn height() -> usize {
        // returns image height
    }

    pub fn width() -> usize {
        // returns image width
    }

    pub fn pixels() -> &Vec<u32> {
        // returns reference to buffer containing pixels
    } 

• only 'raw ppm' format is supported (the most popular format of ppm. More details: ppm format specification ).

• tinyppm supports only True Color images (i.e. 24bits per pixel - 3 color channels & 8 bits per channel). After the image is read it is converted to RGB+A format (32bpp) so that it is ready to be pushed directly to framebuffer.

If you want to check how it works, please have a look at ppm_viewer which is simple image viewer written in Rust: https://github.com/MaciekTalaska/2d_effects/tree/master/ppm_viewer

This code is released under the MIT license.