trying things, things don't work

bent-funny-zone/Cargo.toml

@@ -13,4 +13,5 @@ keywords.workspace = true
 [dependencies]
 anyhow = "1.0.86"
 bmp = "0.5.0"
+dasp_sample = "0.11.0"
 synfx-dsp = "0.5.6"

bent-funny-zone/src/main.rs

@@ -1,10 +1,49 @@
 use std::fs::File;
 
 use anyhow::Result;
-use bmp::open;
+use bmp::{open, Pixel};
+use dasp_sample::{FromSample, Sample, ToSample, U24};
 
 fn main() -> Result<()> {
-    let bmp = open("bmp/sample.bmp")?;
+    dbg!((45 << 16) + (18 << 8) + 143);
+    let mut bmp = open("bmp/sample.bmp")?;
+    for y in 0..bmp.get_height() {
+        for x in 0..bmp.get_width() {
+            if x > 100 && x < 300 {
+                bmp.set_pixel(x, y, Pixel::new(0, 0, 0));
+            }
+        }
+    }
     bmp.to_writer(&mut File::create("bmp/out.bmp")?)?;
     Ok(())
 }
+
+fn rgb_to_sample<T: Sample + FromSample<U24>>(pix: Pixel) -> T {
+    U24::new(((pix.r as i32) << 16) + ((pix.g as i32) << 8) + (pix.b as i32))
+        .unwrap()
+        .to_sample()
+}
+
+fn sample_to_rgb<T: Sample + ToSample<U24>>(sample: T) -> Pixel {
+    let rgb: U24 = sample.to_sample();
+    let rg = rgb >> 8.try_into().unwrap();
+    let r = rg >> 8.try_into().unwrap();
+    Pixel::new(
+        r.inner() as u8,
+        (rg - r).inner() as u8,
+        (rgb - rg).inner() as u8,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use bmp::Pixel;
+
+    use super::{rgb_to_sample, sample_to_rgb};
+
+    #[test]
+    fn rgb2s2rgb() {
+        let pix = Pixel::new(45, 18, 143);
+        assert_eq!(pix, sample_to_rgb(rgb_to_sample::<f64>(pix)));
+    }
+}