Initial working version (but lots of temp stuff)

src/pixel.rs

@@ -0,0 +1,89 @@
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(transparent)]
+pub struct Pixel<const N: usize>([u8; N]);
+
+impl<const N: usize> Pixel<N> {
+    #[inline]
+    pub const fn new() -> Self {
+        Self([0; N])
+    }
+
+    #[inline]
+    pub const fn r(self) -> u8 {
+        self.0[0]
+    }
+
+    #[inline]
+    pub const fn g(self) -> u8 {
+        self.0[1]
+    }
+
+    #[inline]
+    pub const fn b(self) -> u8 {
+        self.0[2]
+    }
+
+    #[inline]
+    pub const fn with_a(mut self, value: u8) -> Self {
+        if N >= 4 {
+            self.0[3] = value;
+        }
+        self
+    }
+
+    #[inline]
+    pub const fn a_or(self, value: u8) -> u8 {
+        if N < 4 {
+            value
+        } else {
+            self.0[3]
+        }
+    }
+
+    #[inline]
+    pub const fn hash_index(self) -> u8 {
+        (self.r() ^ self.g() ^ self.b() ^ self.a_or(0xff)) % 64
+    }
+
+    #[inline]
+    pub fn rgb_add(&mut self, r: u8, g: u8, b: u8) {
+        self.0[0] = self.0[0].wrapping_add(r);
+        self.0[1] = self.0[1].wrapping_add(g);
+        self.0[2] = self.0[2].wrapping_add(b);
+    }
+
+    #[inline]
+    pub fn rgba_add(&mut self, r: u8, g: u8, b: u8, a: u8) {
+        self.rgb_add(r, g, b);
+        if N >= 4 {
+            self.0[3] = self.0[3].wrapping_add(a);
+        }
+    }
+
+    #[inline]
+    pub fn set_r(&mut self, value: u8) {
+        self.0[0] = value;
+    }
+
+    #[inline]
+    pub fn set_g(&mut self, value: u8) {
+        self.0[1] = value;
+    }
+
+    #[inline]
+    pub fn set_b(&mut self, value: u8) {
+        self.0[2] = value;
+    }
+
+    #[inline]
+    pub fn set_a(&mut self, value: u8) {
+        if N >= 4 {
+            self.0[3] = value;
+        }
+    }
+}
+
+pub trait SupportedChannels {}
+
+impl SupportedChannels for Pixel<3> {}
+impl SupportedChannels for Pixel<4> {}