Add Hq{2,3,4}x (#624)

* Scaling works on native

* It works in wasm

* Integrate with UI

* Remove benchmark

* Integrate Hqx into Resizer module

* Link against repo for hqx

* Remove unused defaultOpts

* Re-add test file

* Adding size dropdown

* Chrome: go and sit on the naughty step

* Better docs

* Review

* Add link to crbug

* Update src/codecs/processor-worker/index.ts

Co-Authored-By: Jake Archibald <jaffathecake@gmail.com>

* Terminate worker inbetween resize jobs

codecs/hqx/src/lib.rs

@@ -0,0 +1,55 @@
+extern crate cfg_if;
+extern crate hqx;
+extern crate wasm_bindgen;
+
+mod utils;
+
+use cfg_if::cfg_if;
+use wasm_bindgen::prelude::*;
+
+cfg_if! {
+    // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
+    // allocator.
+    if #[cfg(feature = "wee_alloc")] {
+        extern crate wee_alloc;
+        #[global_allocator]
+        static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+    }
+}
+
+#[wasm_bindgen]
+#[no_mangle]
+pub fn resize(
+    input_image: Vec<u32>,
+    input_width: usize,
+    input_height: usize,
+    factor: usize,
+) -> Vec<u32> {
+    let num_output_pixels = input_width * input_height * factor * factor;
+    let mut output_image = Vec::<u32>::with_capacity(num_output_pixels * 4);
+    output_image.resize(num_output_pixels, 0);
+
+    match factor {
+        2 => hqx::hq2x(
+            input_image.as_slice(),
+            output_image.as_mut_slice(),
+            input_width,
+            input_height,
+        ),
+        3 => hqx::hq3x(
+            input_image.as_slice(),
+            output_image.as_mut_slice(),
+            input_width,
+            input_height,
+        ),
+        4 => hqx::hq4x(
+            input_image.as_slice(),
+            output_image.as_mut_slice(),
+            input_width,
+            input_height,
+        ),
+        _ => unreachable!(),
+    };
+
+    return output_image;
+}