wip: use DitherMethod instead of individual ditherers

Cargo.lock

@@ -167,6 +167,7 @@ checksum = "3a6c9af12842a67734c9a2e355436e5d03b22383ed60cf13cd0c18fbfe3dcbcf"
 dependencies = [
  "async-trait",
  "axum-core",
+ "axum-macros",
  "bytes",
  "futures-util",
  "http",

Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.86"
-axum = { version = "0.7.5", features = ["multipart"] }
+axum = { version = "0.7.5", features = ["macros", "multipart"] }
 axum-macros = "0.4.1"
 clap = { version = "4.5.7", features = ["derive"] }
 epd-waveshare = { git = "https://github.com/caemor/epd-waveshare.git"}

src/api.rs

@@ -1,13 +1,12 @@
-use crate::imageproc::{DiffusionMatrix, Ditherer, EInkImage, ErrorDiffusionDither};
+use crate::imageproc::{DitherMethod, EInkImage, };
 use axum::extract::Multipart;
 use axum::http::StatusCode;
 use axum::response::IntoResponse;
 use axum::{extract::State, response::Response, routing::post, Router};
-use image::ImageReader;
+use image::{DynamicImage, ImageReader};
 use std::io::Cursor;
 use std::time::Duration;
 use tracing::{debug, error, info, instrument};
-use serde::{Serialize, Deserialize};
 
 use crate::display::EInkPanel;
 use std::sync::Arc;
@@ -90,13 +89,14 @@ pub fn router() -> Router<Context> {
         .route("/process_image", post(process_image))
 }
 
-
-
-#[derive(Serialize, Deserialize)]
+#[derive(Debug)]
 pub struct ImageRequest {
+    image: Box<DynamicImage>,
+    
 }
 
 #[instrument(skip(ctx))]
+#[axum::debug_handler]
 async fn set_image(
     State(ctx): State<Context>,
     mut parts: Multipart,
@@ -111,14 +111,15 @@ async fn set_image(
                 .expect("Cursor io never fails");
             debug!("Guessed format: {:?}", reader.format());
 
-            let image = reader.decode()?;
             let mut buf = EInkImage::default();
-            let mut dither = ErrorDiffusionDither::new(DiffusionMatrix::Atkinson);
+            {
+                let image = reader.decode()?;
+                let mut dither = DitherMethod::Atkinson.get_ditherer();
                 dither.dither(&image.into(), &mut buf);
+            }
             let cmd = DisplaySetCommand { img: Box::new(buf) };
             ctx.display_channel
-                .send_timeout(cmd, Duration::from_secs(10))
-                .await?;
+                .send_timeout(cmd, Duration::from_secs(10)).await?;
         }
     }
     Ok(())

src/imageproc.rs

@@ -1,5 +1,6 @@
 use image::{GrayImage, ImageBuffer, Luma, RgbImage};
 use palette::FromColor;
+use serde::{Deserialize, Serialize};
 use tracing::instrument;
 
 use image::Rgb as imgRgb;
@@ -19,6 +20,30 @@ const DISPLAY_PALETTE: [Srgb; 7] = [
     Srgb::new(0.757, 0.443, 0.165), // Orange
 ];
 
+pub enum DitherPalette {}
+
+#[derive(strum::EnumString, Serialize, Deserialize, PartialEq, Eq)]
+pub enum DitherMethod {
+    NearestNeighbor,
+    FloydSteinberg,
+    Atkinson,
+    Stuki,
+    Sierra,
+}
+
+impl DitherMethod {
+    #[must_use]
+    pub fn get_ditherer(&self) -> Box<dyn Ditherer> {
+        match self {
+            Self::NearestNeighbor => Box::new(NNDither {}),
+            Self::Atkinson => Box::new(ErrorDiffusionDither::new(ATKINSON_DITHER_POINTS)),
+            Self::FloydSteinberg => Box::new(ErrorDiffusionDither::new(FLOYD_STEINBERG_POINTS)),
+            Self::Stuki => Box::new(ErrorDiffusionDither::new(STUKI_DITHER_POINTS)),
+            Self::Sierra => Box::new(ErrorDiffusionDither::new(SIERRA_DITHER_POINTS)),
+        }
+    }
+}
+
 pub enum ProcessingError {
     DitherError,
     PaletteIndexError(usize),
@@ -125,6 +150,7 @@ fn compute_error_adjusted_color(orig: &Lab, err: &Lab, weight: f32) -> Lab {
 
 /// ``DiffusionPoint`` is part of the diffusion matrix, represented by a shift in x and y and an error
 /// scaling factor.
+#[derive(Debug)]
 struct DiffusionPoint {
     xshift: i32,
     yshift: i32,
@@ -186,35 +212,19 @@ static STUKI_DITHER_POINTS: &[DiffusionPoint] = &[
     DiffusionPoint::new(1, 2, 1.0 / 42.0),
 ];
 
-#[derive(Debug)]
-pub enum DiffusionMatrix {
-    FloydSteinberg,
-    Atkinson,
-    Sierra,
-    Stuki,
-}
-
-impl DiffusionMatrix {
-    fn value(&self) -> &'static [DiffusionPoint] {
-        match *self {
-            Self::FloydSteinberg => FLOYD_STEINBERG_POINTS,
-            Self::Atkinson => ATKINSON_DITHER_POINTS,
-            Self::Sierra => SIERRA_DITHER_POINTS,
-            Self::Stuki => STUKI_DITHER_POINTS,
-        }
-    }
-}
+pub type DiffusionMatrix<'a> = &'a [DiffusionPoint];
 
 #[derive(Debug)]
-pub struct ErrorDiffusionDither(DiffusionMatrix);
-impl ErrorDiffusionDither {
+pub struct ErrorDiffusionDither<'a>(&'a [DiffusionPoint]);
+
+impl<'a> ErrorDiffusionDither<'a> {
     #[must_use]
-    pub const fn new(dm: DiffusionMatrix) -> Self {
+    pub const fn new(dm: DiffusionMatrix<'a>) -> Self {
         Self(dm)
     }
 }
 
-impl Ditherer for ErrorDiffusionDither {
+impl<'a> Ditherer for ErrorDiffusionDither<'a> {
     #[instrument]
     fn dither(&mut self, img: &RgbImage, output: &mut EInkImage) {
         // create a copy of the image in Lab space, mutable.
@@ -226,8 +236,8 @@ impl Ditherer for ErrorDiffusionDither {
         for pix in srgb {
             temp_img.push(pix.into_format().into_color());
         }
-        // now we take our units.
 
+        // TODO: rework this to make more sense.
         for y in 0..ysize {
             for x in 0..xsize {
                 let index = coord_to_idx(x, y, xsize);
@@ -236,7 +246,8 @@ impl Ditherer for ErrorDiffusionDither {
                 // set the color in the output buffer.
                 *output.buf.get_mut(index).unwrap() = nearest;
                 // take the error, and propagate it.
-                for point in self.0.value() {
+                for point in self.0 {
+                    // bounds checking.
                     let Some(target_x) = x.checked_add_signed(point.xshift) else {
                         continue;
                     };

src/main.rs

@@ -3,8 +3,8 @@ pub mod display;
 pub mod errors;
 pub mod imageproc;
 
-use crate::display::{FakeEInk, EInkPanel, Wrapper};
-use crate::imageproc::{DiffusionMatrix, Ditherer, EInkImage, ErrorDiffusionDither};
+use crate::display::{EInkPanel, FakeEInk, Wrapper};
+use crate::imageproc::{DitherMethod, EInkImage};
 use clap::{Parser, Subcommand};
 use image::RgbImage;
 use tracing::{error, info};
@@ -39,7 +39,7 @@ async fn main() -> anyhow::Result<()> {
         let mut display = FakeEInk {};
 
         let mut eink_buf = EInkImage::default();
-        let mut dither = ErrorDiffusionDither::new(DiffusionMatrix::Atkinson);
+        let mut dither = DitherMethod::Atkinson.get_ditherer();
 
         dither.dither(&img, &mut eink_buf);
         display.display(&eink_buf)?;