From 8577bbd70d08e68988f283e68ccff412562b5e4d Mon Sep 17 00:00:00 2001
From: "Christopher N. Hesse" <raymanfx@gmail.com>
Date: Sun, 5 Feb 2023 20:58:12 +0100
Subject: [PATCH] Simplify Pixel trait

Signed-off-by: Christopher N. Hesse <raymanfx@gmail.com>
---
 ffimage-yuv/src/yuv.rs    | 10 ++-------
 ffimage-yuv/src/yuv422.rs | 11 +++-------
 ffimage/src/color/gray.rs | 10 ++-------
 ffimage/src/color/rgb.rs  | 44 ++++++++++++++-------------------------
 ffimage/src/lib.rs        |  5 ++---
 5 files changed, 25 insertions(+), 55 deletions(-)

diff --git a/ffimage-yuv/src/yuv.rs b/ffimage-yuv/src/yuv.rs
index 47fc13f..83559f4 100644
--- a/ffimage-yuv/src/yuv.rs
+++ b/ffimage-yuv/src/yuv.rs
@@ -33,13 +33,7 @@ impl<T, const Y: usize, const U: usize, const V: usize> DerefMut for Yuv<T, Y, U
 }
 
 impl<T, const Y: usize, const U: usize, const V: usize> Pixel for Yuv<T, Y, U, V> {
-    fn channels() -> u8 {
-        3
-    }
-
-    fn subpixels() -> u8 {
-        1
-    }
+    const CHANNELS: u8 = 3;
 }
 
 impl<
@@ -109,6 +103,6 @@ mod tests {
 
     #[test]
     fn channels() {
-        assert_eq!(Yuv::<u8>::channels(), 3);
+        assert_eq!(Yuv::<u8>::CHANNELS, 3);
     }
 }
diff --git a/ffimage-yuv/src/yuv422.rs b/ffimage-yuv/src/yuv422.rs
index f03a9b7..a4d7205 100644
--- a/ffimage-yuv/src/yuv422.rs
+++ b/ffimage-yuv/src/yuv422.rs
@@ -46,13 +46,8 @@ impl<T, const Y0: usize, const Y1: usize, const U: usize, const V: usize> DerefM
 impl<T, const Y0: usize, const Y1: usize, const U: usize, const V: usize> Pixel
     for Yuv422<T, Y0, Y1, U, V>
 {
-    fn channels() -> u8 {
-        4
-    }
-
-    fn subpixels() -> u8 {
-        2
-    }
+    const CHANNELS: u8 = 4;
+    const SUBPIXELS: u8 = 2;
 }
 
 impl<T, const Y0: usize, const Y1: usize, const U: usize, const V: usize>
@@ -89,6 +84,6 @@ mod tests {
 
     #[test]
     fn channels() {
-        assert_eq!(Yuv422::<u8, 0, 2, 1, 3>::channels(), 4);
+        assert_eq!(Yuv422::<u8, 0, 2, 1, 3>::CHANNELS, 4);
     }
 }
diff --git a/ffimage/src/color/gray.rs b/ffimage/src/color/gray.rs
index 1d4965b..7f46760 100644
--- a/ffimage/src/color/gray.rs
+++ b/ffimage/src/color/gray.rs
@@ -29,13 +29,7 @@ impl<T> DerefMut for Gray<T> {
 }
 
 impl<T> Pixel for Gray<T> {
-    fn channels() -> u8 {
-        1
-    }
-
-    fn subpixels() -> u8 {
-        1
-    }
+    const CHANNELS: u8 = 1;
 }
 
 impl<T, U, const R: usize, const G: usize, const B: usize> From<Rgb<U, R, G, B>> for Gray<T>
@@ -68,7 +62,7 @@ mod tests {
 
     #[test]
     fn channels() {
-        assert_eq!(Gray::<u8>::channels(), 1);
+        assert_eq!(Gray::<u8>::CHANNELS, 1);
     }
 
     #[test]
diff --git a/ffimage/src/color/rgb.rs b/ffimage/src/color/rgb.rs
index 44b3942..6bcb7cc 100644
--- a/ffimage/src/color/rgb.rs
+++ b/ffimage/src/color/rgb.rs
@@ -8,15 +8,15 @@ use crate::Pixel;
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 pub struct Rgb<T, const R: usize = 0, const G: usize = 1, const B: usize = 2>(pub [T; 3]);
 
+/// BGR pixel
+pub type Bgr<T> = Rgb<T, 2, 1, 0>;
+
 impl<T, const R: usize, const G: usize, const B: usize> From<[T; 3]> for Rgb<T, R, G, B> {
     fn from(value: [T; 3]) -> Self {
         Rgb(value)
     }
 }
 
-/// BGR pixel
-pub type Bgr<T> = Rgb<T, 2, 1, 0>;
-
 impl<T, const R: usize, const G: usize, const B: usize> Deref for Rgb<T, R, G, B> {
     type Target = [T; 3];
 
@@ -32,13 +32,7 @@ impl<T, const R: usize, const G: usize, const B: usize> DerefMut for Rgb<T, R, G
 }
 
 impl<T, const R: usize, const G: usize, const B: usize> Pixel for Rgb<T, R, G, B> {
-    fn channels() -> u8 {
-        3
-    }
-
-    fn subpixels() -> u8 {
-        1
-    }
+    const CHANNELS: u8 = 3;
 }
 
 impl<T, U> From<Rgb<U, 2, 1, 0>> for Rgb<T, 0, 1, 2>
@@ -61,6 +55,15 @@ where
     }
 }
 
+/// RGB pixel with alpha channel
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub struct Rgba<T, const R: usize = 0, const G: usize = 1, const B: usize = 2, const A: usize = 3>(
+    pub [T; 4],
+);
+
+/// BGR pixel with alpha channel
+pub type Bgra<T> = Rgba<T, 2, 1, 0, 3>;
+
 impl<
         T,
         U,
@@ -85,15 +88,6 @@ where
     }
 }
 
-/// RGB pixel with alpha channel
-#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
-pub struct Rgba<T, const R: usize = 0, const G: usize = 1, const B: usize = 2, const A: usize = 3>(
-    pub [T; 4],
-);
-
-/// BGR pixel with alpha channel
-pub type Bgra<T> = Rgba<T, 2, 1, 0, 3>;
-
 impl<T, const R: usize, const G: usize, const B: usize, const A: usize> Deref
     for Rgba<T, R, G, B, A>
 {
@@ -115,13 +109,7 @@ impl<T, const R: usize, const G: usize, const B: usize, const A: usize> DerefMut
 impl<T, const R: usize, const G: usize, const B: usize, const A: usize> Pixel
     for Rgba<T, R, G, B, A>
 {
-    fn channels() -> u8 {
-        4
-    }
-
-    fn subpixels() -> u8 {
-        1
-    }
+    const CHANNELS: u8 = 4;
 }
 
 impl<T, U> From<Rgba<U, 2, 1, 0, 3>> for Rgba<T, 0, 1, 2, 3>
@@ -185,8 +173,8 @@ mod tests {
 
     #[test]
     fn channels() {
-        assert_eq!(Rgb::<u8>::channels(), 3);
-        assert_eq!(Rgba::<u8>::channels(), 4);
+        assert_eq!(Rgb::<u8>::CHANNELS, 3);
+        assert_eq!(Rgba::<u8>::CHANNELS, 4);
     }
 
     #[test]
diff --git a/ffimage/src/lib.rs b/ffimage/src/lib.rs
index 0c94fbd..c59fdea 100644
--- a/ffimage/src/lib.rs
+++ b/ffimage/src/lib.rs
@@ -45,10 +45,9 @@
 /// Generic pixel attributes
 pub trait Pixel {
     /// Number of channels for this pixel
-    fn channels() -> u8;
-
+    const CHANNELS: u8;
     /// Number of image pixels for this pixel
-    fn subpixels() -> u8;
+    const SUBPIXELS: u8 = 1;
 }
 
 pub mod color;