Add Color trait

showbits-common/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 
 [dependencies]
 anyhow = "1.0.80"
+palette = "0.7.5"
 
 [lints]
 workspace = true

showbits-common/src/color.rs

@@ -0,0 +1,11 @@
+use palette::Srgb;
+
+pub trait Color: Copy {
+    /// Convert to an sRGB color.
+    ///
+    /// Useful for debugging or dithering.
+    fn to_srgb(self) -> Srgb;
+
+    /// Combine two colors by putting one "over" the other.
+    fn over(self, below: Self) -> Self;
+}

showbits-common/src/lib.rs

@@ -1,6 +1,7 @@
-pub use crate::{buffer::*, rect::*, vec2::*, view::*, widget::*};
+pub use crate::{buffer::*, color::*, rect::*, vec2::*, view::*, widget::*};
 
 mod buffer;
+mod color;
 mod rect;
 mod vec2;
 mod view;