Initial + split from my custom roguelike engine

src/palette.rs

@@ -0,0 +1,19 @@
+//! Palette-Presets.
+
+/// RGB332-Palette: 8 Levels Rot, 8 Levels Grün, 4 Levels Blau.
+///
+/// Index-Bits: `RRRGGGBB` — `r = idx / 32`, `g = (idx / 4) % 8`, `b = idx % 4`.
+pub const RGB332: [[u8; 3]; 256] = {
+    let mut p = [[0u8; 3]; 256];
+    let mut i = 0;
+    while i < 256 {
+        let r = (i / 32) as u32;        // 0..=7
+        let g = ((i / 4) % 8) as u32;   // 0..=7
+        let b = (i % 4) as u32;         // 0..=3
+        p[i][0] = ((r * 255) / 7) as u8;
+        p[i][1] = ((g * 255) / 7) as u8;
+        p[i][2] = ((b * 255) / 3) as u8;
+        i += 1;
+    }
+    p
+};