From 0324f5f389cd369f4b8e73d5f6c0f002705fe5dd Mon Sep 17 00:00:00 2001
From: Max Bradbury <max@tinybird.info>
Date: Sun, 15 Nov 2020 16:54:25 +0000
Subject: [PATCH] wip wtf

---
 Cargo.toml |  1 +
 index.pug  |  7 ++++--
 src/lib.rs | 67 ++++++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 3738210..2a5c73c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,7 @@ crate-type = ["cdylib"]
 [dependencies]
 base64 = "^0.12.3"
 bitsy-parser = "^0.72.5"
+dither = "^1.3.9"
 image = "^0.23.7"
 json = "^0.12.4"
 lazy_static = "^1.4.0"
diff --git a/index.pug b/index.pug
index 27f4c8d..f8b893b 100644
--- a/index.pug
+++ b/index.pug
@@ -74,9 +74,12 @@ html(lang="en-gb")
                                         input#colour-foreground(type="color" value="#ffffff")
 
                                 label
-                                    input#dither(type="checkbox" checked=true)
                                     | dither
-                                br
+                                    select#dither
+                                    option None
+                                    option(value="Atkinson" selected=true) Atkinson
+                                    option(value="Bayer4x4") Bayer 4×4
+                                    option(value="FloydSteinberg") Floyd-Steinberg
 
                 button.pagination.prev#back-to-image previous
                 button.pagination.next#room-next add room
diff --git a/src/lib.rs b/src/lib.rs
index b6178a1..5669d2f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,6 +3,7 @@
 use bitsy_parser::game::Game;
 use bitsy_parser::image::Image;
 use bitsy_parser::tile::Tile;
+use dither::prelude::Dither;
 use image::{GenericImageView, Pixel, DynamicImage};
 use image::imageops::ColorMap;
 use image::imageops::FilterType::CatmullRom;
@@ -27,12 +28,18 @@ enum SelectedPalette {
     }
 }
 
+enum DitherAlgorithm {
+    Atkinson,
+    Bayer4x4,
+    FloydSteinberg,
+}
+
 struct State {
     game:       Option<Game>,
     image:      Option<DynamicImage>,
     room_name:  Option<String>,
     palette:    SelectedPalette,
-    dither:     bool,
+    dither:     Option<DitherAlgorithm>,
     brightness: i32,
 }
 
@@ -43,7 +50,7 @@ lazy_static! {
             image:      None,
             room_name:  None,
             palette:    SelectedPalette::None,
-            dither:     true,
+            dither:     Some(DitherAlgorithm::Atkinson),
             brightness: 0,
         }
     );
@@ -126,9 +133,15 @@ pub fn load_image(image_base64: String) -> String {
 }
 
 #[wasm_bindgen]
-pub fn set_dither(dither: bool) {
+pub fn set_dither(dither: &str) {
     let mut state = STATE.lock().unwrap();
-    state.dither = dither;
+
+    state.dither = match dither {
+        "Atkinson"       => Some(DitherAlgorithm::Atkinson),
+        "Bayer4x4"       => Some(DitherAlgorithm::Bayer4x4),
+        "FloydSteinberg" => Some(DitherAlgorithm::FloydSteinberg),
+        _                => None,
+    }
 }
 
 #[wasm_bindgen]
@@ -204,25 +217,55 @@ fn render_preview(state: &State) -> DynamicImage {
     let mut buffer = state.image.as_ref().unwrap().clone().into_rgba();
 
     let palette = match &state.palette {
-        SelectedPalette::None => bitsy_parser::mock::game_default().palettes[0].clone(),
-        SelectedPalette::Existing { id } => state.game.as_ref().unwrap().get_palette(id).unwrap().clone(),
-        SelectedPalette::New { background, foreground } => palette_from(background, foreground),
+        SelectedPalette::None => {
+            bitsy_parser::mock::game_default().palettes[0].clone()
+        },
+        SelectedPalette::Existing { id } => {
+            state.game.as_ref().unwrap().get_palette(id).unwrap().clone()
+        },
+        SelectedPalette::New { background, foreground } => {
+            palette_from(background, foreground)
+        },
     };
 
     let colour_map = crate::ColourMap::from(&palette);
 
     // adjust brightness
-    let mut buffer = image::imageops::brighten(&mut buffer, state.brightness);
+    let mut buffer = image::imageops::brighten(
+        &mut buffer,
+        state.brightness
+    );
 
-    if state.dither {
-        image::imageops::dither(&mut buffer, &colour_map);
+    if state.dither.is_some() {
+        // image::imageops::dither(&mut buffer, &colour_map);
+
+        // so, what needs doing?
+        // convert the buffer to the format required by the dither crate
+
+        let dither_img = dither::prelude::Img::new(buffer.iter(), 128).unwrap();
+
+        // run the dither according to user preference
+
+        // todo what is the quantise function supposed to be like?
+        // dither::ditherer::ATKINSON.dither(dither_img, colour_map);
+
+        // convert the dither format back to an ImageBuffer
+        // buffer = image::ImageBuffer::new(128, 128); //from_vec(128, 128, pixels).unwrap();
+        //
+        // for pixel in dither_img.iter() {
+        //     // todo enumerate?
+        //     buffer.put_pixel(0,0, image::Rgba::from([0,0,0,0]));
+        // }
     } else {
         // just do colour indexing
-        let indices = image::imageops::colorops::index_colors(&mut buffer, &colour_map);
+        let colour_indices = image::imageops::colorops::index_colors(
+            &mut buffer,
+            &colour_map
+        );
 
         // todo get rid of magic numbers! what about Bitsy HD?
         buffer = image::ImageBuffer::from_fn(128, 128, |x, y| -> image::Rgba<u8> {
-            let p = indices.get_pixel(x, y);
+            let p = colour_indices.get_pixel(x, y);
 
             colour_map
                 .lookup(p.0[0] as usize)