add benchmark

benches/dithering.rs

@@ -1,15 +1,27 @@
-use criterion::{black_box, criterion_group, criterion_main, Criterion};
-
-fn fibonacci(n: u64) -> u64 {
-    match n {
-        0 => 1,
-        1 => 1,
-        n => fibonacci(n-1) + fibonacci(n-2),
-    }
-}
+use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
+use image::{ImageReader, RgbImage};
+use pi_frame_server::dither::{DitherMethod, DitheredImage, Palette};
 
 fn criterion_benchmark(c: &mut Criterion) {
-    c.bench_function("fib 20", |b| b.iter(|| fibonacci(black_box(20))));
+    let sample_file = "sample_0.tiff";
+    let image: RgbImage = ImageReader::open(format!("samples/{sample_file}"))
+        .expect("file exists")
+        .decode()
+        .expect("file is valid")
+        .into_rgb8();
+
+    c.bench_with_input(BenchmarkId::new("dither", "sample_0"), &image, |b, i| {
+        b.iter(|| {
+            let mut method = DitherMethod::Atkinson.get_ditherer();
+            let mut result = DitheredImage::new(
+                image.width(),
+                image.height(),
+                Palette::Default.value().to_vec(),
+            );
+
+            method.dither(i, &mut result);
+        });
+    });
 }
 
 criterion_group!(benches, criterion_benchmark);