From 36ccf4d4bf57f12dae13543b37453dc6433018e5 Mon Sep 17 00:00:00 2001
From: gennyble <gen@nyble.dev>
Date: Mon, 10 Jun 2024 17:17:55 -0500
Subject: Use leftover bits in HighestBits selector

---
 squash/Cargo.toml | 12 ++++++------
 src/selection.rs  | 21 ++++++++++++++++-----
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/squash/Cargo.toml b/squash/Cargo.toml
index 3d94c1a..12889f3 100644
--- a/squash/Cargo.toml
+++ b/squash/Cargo.toml
@@ -7,14 +7,14 @@ license = "ISC"
 description = "CLI tool for quantizing colours"
 repository = "https://github.com/gennyble/colorsquash/tree/main/squash"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
 # the meat 'o the thing! the meaning behind it all
-colorsquash = { path = "..", version = "0.2.0", default-features = false, features = [
-	"gifed",
-] }
+[dependencies.colorsquash]
+path = ".."
+version = "0.2.0"
+default-features = false # `kmeans` crate currently very broken
+features = ["gifed"]
 
+[dependencies]
 # just useful tools for writing binaries
 anyhow = "1.0.75"
 camino = "1.1.6"
diff --git a/src/selection.rs b/src/selection.rs
index 84d5ea3..aee3b2f 100644
--- a/src/selection.rs
+++ b/src/selection.rs
@@ -337,17 +337,28 @@ pub struct HighestBits {}
 
 impl Selector for HighestBits {
 	fn select(&mut self, max_colors: usize, image: ImageData) -> Vec<RGB8> {
-		let max_bits = max_colors.next_power_of_two().ilog2() / 3;
-		let shift = 8 - max_bits;
+		let bits = max_colors.next_power_of_two().ilog2();
+		let leftover = bits % 3;
+		let shift = 8 - (bits / 3);
+
+		//TODO: gen- we're taking red/green here because, as i remember, they
+		// are the colours to which we are most sensetive? but it would be cool
+		// if this was selectable
+		let (rshift, gshift, bshift) = match leftover {
+			0 => (shift, shift, shift),
+			1 => (shift, shift - 1, shift),
+			2 => (shift - 1, shift - 1, shift),
+			_ => unreachable!(),
+		};
 
 		image
 			.0
 			.iter()
 			.map(|color| {
 				RGB8::new(
-					color.r >> shift << shift,
-					color.g >> shift << shift,
-					color.b >> shift << shift,
+					color.r >> rshift << rshift,
+					color.g >> gshift << gshift,
+					color.b >> bshift << bshift,
 				)
 			})
 			.collect::<HashSet<_>>()
-- 
cgit 1.4.1-3-g733a5