Image is now mapped to a pixel-identical image

Cargo.lock

@@ -8,6 +8,15 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -29,6 +38,16 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a19187fea3ac7e84da7dacf48de0c45d63c6a76f9490dae389aead16c243fce3"
+dependencies = [
+ "log",
+ "regex",
+]
+
 [[package]]
 name = "fdeflate"
 version = "0.3.4"
@@ -48,6 +67,35 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a06fddc2749e0528d2813f95e050e87e52c8cbbae56223b9babf73b3e53b0cc6"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.153"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
+
+[[package]]
+name = "log"
+version = "0.4.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+
+[[package]]
+name = "memchr"
+version = "2.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c8640c5d730cb13ebd907d8d04b52f55ac9a2eec55b440c8892f40d56c76c1d"
+
 [[package]]
 name = "miniz_oxide"
 version = "0.7.2"
@@ -71,11 +119,70 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "quickcheck"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
+dependencies = [
+ "env_logger",
+ "log",
+ "rand",
+]
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "regex"
+version = "1.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c117dbdfde9c8308975b6a18d71f3f385c89461f7b3fb054288ecf2a2058ba4c"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86b83b8b9847f9bf95ef68afb0b8e6cdb80f498442f5179a29fad448fcc1eaea"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adad44e29e4c806119491a7f06f03de4d1af22c3a680dd47f1e6e179439d1f56"
+
 [[package]]
 name = "rximg"
 version = "0.1.0"
 dependencies = [
  "png",
+ "quickcheck",
 ]
 
 [[package]]
@@ -83,3 +190,9 @@ name = "simd-adler32"
 version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 
 [dependencies]
 png = "0.17.13"
+quickcheck = "1.0.3"

src/main.rs

@@ -70,7 +70,7 @@ fn save_image(width: usize, height: usize, image: Vec<Vec<u8>>) {
     assert_eq!(image.len(), 3);
 
     let mut encoder = png::Encoder::new(
-        File::create("outputs/avatar2.png").unwrap(),
+        File::create("outputs/avatar2_out.png").unwrap(),
         width as u32, height as u32, 
     );
     encoder.set_color(ColorType::Rgb);

src/transform.rs

@@ -38,3 +38,34 @@ fn transform(data: &mut [i32], zero: usize, stride: usize, divisor: i32) {
         data[ix(GRAY[i])] = row[i] / divisor;
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use quickcheck::{quickcheck, Arbitrary};
+
+    use crate::{constants::TILE_SZ, transform::{decode, encode}};
+
+    #[derive(Clone, Debug)]
+    struct Encodable { args: [i32; TILE_SZ] }
+
+    impl Arbitrary for Encodable {
+        fn arbitrary(g: &mut quickcheck::Gen) -> Self {
+            let mut args = [0; TILE_SZ];
+            for i in 0..TILE_SZ {
+                args[i] = i16::arbitrary(g) as i32;
+            }
+            return Encodable { args };
+        }
+    }
+
+    quickcheck! {
+        fn reversible(xs: Encodable) -> bool {
+            let orig = xs.args;
+            let mut enc = orig.clone();
+            encode(&mut enc, 0, 1);
+            let mut dec = enc.clone();
+            decode(&mut dec, 0, 1);
+            orig == dec
+        }
+    }
+}