gistfile1.txt

use wasm_bindgen::prelude::*;

// RACE 1: Light Task (Grayscale conversion)
#[wasm_bindgen]
pub fn apply_grayscale_wasm(pixels: &mut [u8]) {
    for i in (0..pixels.len()).step_by(4) {
        let r = pixels[i] as u32;
        let g = pixels[i + 1] as u32;
        let b = pixels[i + 2] as u32;
        let avg = ((r + g + b) / 3) as u8;
        
        pixels[i] = avg;
        pixels[i + 1] = avg;
        pixels[i + 2] = avg;
    }
}

// RACE 2: Heavy Task (Sharpen)
#[wasm_bindgen]
pub fn apply_sharpen_wasm(pixels: &mut [u8], width: u32, height: u32) {
    let copy = pixels.to_vec();
    for y in 1..(height - 1) {
        for x in 1..(width - 1) {
            let i = ((y * width + x) * 4) as usize;
            for c in 0..3 {
                let center = i + c;
                let top = center - (width * 4) as usize;
                let bottom = center + (width * 4) as usize;
                let val = 5 * copy[center] as i32 
                          - copy[top] as i32 - copy[bottom] as i32 
                          - copy[center - 4] as i32 - copy[center + 4] as i32;
                pixels[center] = val.clamp(0, 255) as u8;
            }
        }
    }
}