Dither images using wasm plugin

showbits-thermal-printer/src/documents.rs

@@ -1,7 +1,8 @@
 use showbits_typst::Typst;
 
-pub use self::text::*;
+pub use self::{image::*, text::*};
 
+mod image;
 mod text;
 
 fn typst_with_lib() -> Typst {

showbits-thermal-printer/src/documents/image/lib.typ

@@ -0,0 +1 @@
+../lib.typ

showbits-thermal-printer/src/documents/image/main.typ

@@ -0,0 +1,4 @@
+#import "lib.typ";
+#show: it => lib.init(it)
+
+#lib.dither("image.png")

showbits-thermal-printer/src/documents/image/mod.rs

@@ -0,0 +1,24 @@
+use std::io::Cursor;
+
+use anyhow::Context;
+use image::{ImageFormat, RgbaImage};
+use showbits_typst::Typst;
+
+pub struct Image {
+    pub image: RgbaImage,
+}
+
+impl Image {
+    pub fn into_typst(self) -> anyhow::Result<Typst> {
+        let mut bytes: Vec<u8> = Vec::new();
+        self.image
+            .write_to(&mut Cursor::new(&mut bytes), ImageFormat::Png)
+            .context("failed to encode image as png")?;
+
+        let typst = super::typst_with_lib()
+            .with_file("/image.png", bytes)
+            .with_main_file(include_str!("main.typ"));
+
+        Ok(typst)
+    }
+}

showbits-thermal-printer/src/documents/image/plugin.wasm

@@ -0,0 +1 @@
+../plugin.wasm

showbits-thermal-printer/src/documents/lib.typ

@@ -20,4 +20,14 @@
 // the same size after tearing off the paper.
 #let feed = v(64pt + 32pt)
 
-#import plugin("plugin.wasm") as plugin
+////////////
+// Plugin //
+////////////
+
+#import plugin("plugin.wasm") as p
+
+#let dither(path) = {
+  let bytes = read(path, encoding: none)
+  let dithered = p.dither(bytes)
+  image(dithered)
+}

showbits-thermal-printer/src/main.rs

@@ -1,8 +1,8 @@
+mod documents;
 mod drawer;
 mod persistent_printer;
 mod printer;
 mod server;
-mod documents;
 
 use std::{path::PathBuf, time::Duration};
 

showbits-thermal-printer/src/server.rs

@@ -14,7 +14,7 @@ use showbits_common::widgets::DitherAlgorithm;
 use tokio::{net::TcpListener, sync::mpsc};
 
 use crate::{
-    documents::Text,
+    documents::{Image, Text},
     drawer::{
         CalendarDrawing, CellsDrawing, ChatMessageDrawing, Command, EggDrawing, ImageDrawing,
         NewTypstDrawing, PhotoDrawing, TextDrawing, TicTacToeDrawing, TypstDrawing,
@@ -40,6 +40,7 @@ pub async fn run(tx: mpsc::Sender<Command>, addr: String) -> anyhow::Result<()>
         .route("/tictactoe", post(post_tictactoe))
         .route("/typst", post(post_typst).fallback(get_static_file))
         .route("/test", post(post_test).fallback(get_static_file))
+        .route("/test2", post(post_test2).fallback(get_static_file))
         .fallback(get(get_static_file))
         .layer(DefaultBodyLimit::max(32 * 1024 * 1024)) // 32 MiB
         .with_state(Server { tx });
@@ -235,3 +236,33 @@ async fn post_test(server: State<Server>, request: Form<Text>) {
         .send(Command::draw(NewTypstDrawing::new(request.0)))
         .await;
 }
+
+// /test2
+
+async fn post_test2(server: State<Server>, mut multipart: Multipart) -> somehow::Result<Response> {
+    let mut image = None;
+
+    while let Some(field) = multipart.next_field().await? {
+        match field.name() {
+            Some("image") => {
+                let data = field.bytes().await?;
+                let decoded = image::load_from_memory(&data)?.into_rgba8();
+                image = Some(decoded);
+            }
+            _ => {}
+        }
+    }
+
+    let Some(image) = image else {
+        return Ok(status_code(StatusCode::UNPROCESSABLE_ENTITY));
+    };
+
+    let image = Image { image }.into_typst().map_err(somehow::Error)?;
+
+    let _ = server
+        .tx
+        .send(Command::draw(NewTypstDrawing::new(image)))
+        .await;
+
+    Ok(().into_response())
+}