feat(init,display): loader streams ELF segments (any size, kills half-built proc); window pixels RGBA8 premul (tiny-skia native), canvas mapped plain memory + pixels_mut/touch

crates/types/src/display.rs

@@ -16,6 +16,17 @@ impl Color {
     pub const fn rgba(r: u8, g: u8, b: u8, a: u8) -> Self {
         Self(((a as u32) << 24) | ((r as u32) << 16) | ((g as u32) << 8) | (b as u32))
     }
+
+    /// As a window's pixel is stored: the bytes R, G, B, A (see
+    /// `window::BUFFER`).
+    pub const fn to_rgba(self) -> [u8; 4] {
+        let [b, g, r, a] = self.0.to_le_bytes();
+        [r, g, b, a]
+    }
+
+    pub const fn from_rgba([r, g, b, a]: [u8; 4]) -> Self {
+        Self(u32::from_le_bytes([b, g, r, a]))
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
@@ -61,9 +72,10 @@ pub mod window {
     /// (`pack_name`). Reply `[OK, width, height, 0]` carrying the window
     /// capability, which the launcher passes on; the new window is in front.
     pub const OPEN: usize = 1;
-    /// Through a window: reply `[OK, width, height, 0]` carrying its pixel buffer, a
-    /// region the holder maps read-write: `width * height` pixels, rows
-    /// one after another, each pixel a `Color` as a little-endian u32.
+    /// Through a window: reply `[OK, width, height, 0]` carrying its pixel
+    /// buffer, a region the holder maps read-write: `width * height`
+    /// pixels, rows one after another, each pixel the bytes R, G, B, A
+    /// (alpha premultiplied; the display shows it as opaque).
     pub const BUFFER: usize = 2;
     /// Through a window: the rectangle (`pack_rect`) that changed.
     pub const PRESENT: usize = 3;