Add more dithering options

showbits-thermal-printer-ui/src/components/CDocumentXkcd.vue

@@ -7,12 +7,16 @@ const { disabled, error, makeRequest } = useApiRequest();
 const form = useTemplateRef<HTMLFormElement>("form");
 
 const number = ref<number>();
+const dither = ref(true);
+const bright = ref(false);
 const feed = ref(true);
 
 function submit() {
   const data = new URLSearchParams();
   if (typeof number.value === "number")
     data.append("number", number.value.toFixed());
+  data.append("dither", String(dither.value));
+  data.append("bright", String(bright.value));
   data.append("feed", String(feed.value));
   void makeRequest("api/xkcd", data);
 }
@@ -33,7 +37,18 @@ function submit() {
       />
     </label>
 
-    <label><input v-model="feed" type="checkbox" :disabled /> Feed</label>
+    <div class="wide">
+      <label><input v-model="dither" type="checkbox" :disabled /> Dither</label>
+      <label
+        ><input
+          v-model="bright"
+          type="checkbox"
+          :disabled="disabled || !dither"
+        />
+        Bright</label
+      >
+      <label><input v-model="feed" type="checkbox" :disabled /> Feed</label>
+    </div>
 
     <button :disabled>Print</button>
     <CError :message="error" />

showbits-thermal-printer/src/documents/xkcd/data.json

@@ -2,5 +2,6 @@
   "number": 3064,
   "title": "Lungfish",
   "alt": "I know having so many base pairs makes rebasing complicated, but you're in Bilateria, so shouldn't you at LEAST be better at using git head?",
+  "dither": false,
   "feed": false
 }

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

@@ -9,14 +9,18 @@
   #text(size: 32pt, data.title)
 ]
 
-// If the image is an odd number of pixels wide, we need to add an extra row of
-// pixels (in this case, on the right) to ensure that the image pixels fall on
-// screen pixels.
-#context {
-  let img = image("image.png")
-  let width = measure(img).width
-  let additional = 2pt * calc.fract(width.pt() / 2)
-  align(center, stack(dir: ltr, img, h(additional)))
+#if data.dither {
+  // If the image is an odd number of pixels wide, we need to add an extra row
+  // of pixels (in this case, on the right) to ensure that the image pixels fall
+  // on screen pixels.
+  context {
+    let img = image("image.png")
+    let width = measure(img).width
+    let additional = 2pt * calc.fract(width.pt() / 2)
+    align(center, stack(dir: ltr, img, h(additional)))
+  }
+} else {
+  image("image.png", width: lib.width)
 }
 
 #align(center, data.alt)

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

@@ -24,12 +24,15 @@ struct Data {
     number: u32,
     title: String,
     alt: String,
+    dither: bool,
     feed: bool,
 }
 
 #[derive(Deserialize)]
 pub struct FormData {
     pub number: Option<u32>,
+    pub dither: Option<bool>,
+    pub bright: Option<bool>,
     pub feed: Option<bool>,
 }
 
@@ -46,20 +49,29 @@ pub async fn post(server: State<Server>, Form(form): Form<FormData>) -> somehow:
     let info = client.get(url).send().await?.json::<ComicInfo>().await?;
 
     let image_data = client.get(&info.img).send().await?.bytes().await?;
-    let image = image::load_from_memory(&image_data)?.into_rgba8();
-
-    let max_width = Some(384);
-    let max_height = Some(1024);
-    let image = super::image::dither(image, max_width, max_height, false, "stucki")
-        .map_err(somehow::Error)?;
+    let mut image = image::load_from_memory(&image_data)?.into_rgba8();
 
     let data = Data {
         number: info.num,
         title: info.title,
         alt: info.alt,
+        dither: form.dither.unwrap_or(true),
         feed: form.feed.unwrap_or(true),
     };
 
+    if data.dither {
+        let max_width = Some(384);
+        let max_height = Some(1024);
+        image = super::image::dither(
+            image,
+            max_width,
+            max_height,
+            form.bright.unwrap_or(false),
+            "stucki",
+        )
+        .map_err(somehow::Error)?;
+    }
+
     let mut bytes: Vec<u8> = Vec::new();
     image
         .write_to(&mut Cursor::new(&mut bytes), ImageFormat::Png)