refactor overlay windowing

wlx-overlay-s/src/windowing/mod.rs

@@ -0,0 +1,45 @@
+use glam::{Affine3A, Vec3A};
+use slotmap::new_key_type;
+use std::sync::Arc;
+
+pub mod backend;
+pub mod manager;
+mod set;
+pub mod window;
+
+new_key_type! {
+    pub struct OverlayID;
+}
+
+#[derive(Clone, Debug)]
+pub enum OverlaySelector {
+    Id(OverlayID),
+    Name(Arc<str>),
+}
+
+pub const Z_ORDER_TOAST: u32 = 70;
+pub const Z_ORDER_LINES: u32 = 69;
+pub const Z_ORDER_WATCH: u32 = 68;
+pub const Z_ORDER_ANCHOR: u32 = 67;
+pub const Z_ORDER_DEFAULT: u32 = 0;
+pub const Z_ORDER_DASHBOARD: u32 = Z_ORDER_DEFAULT;
+
+pub fn snap_upright(transform: Affine3A, up_dir: Vec3A) -> Affine3A {
+    if transform.x_axis.dot(up_dir).abs() < 0.2 {
+        let scale = transform.x_axis.length();
+        let col_z = transform.z_axis.normalize();
+        let col_y = up_dir;
+        let col_x = col_y.cross(col_z);
+        let col_y = col_z.cross(col_x).normalize();
+        let col_x = col_x.normalize();
+
+        Affine3A::from_cols(
+            col_x * scale,
+            col_y * scale,
+            col_z * scale,
+            transform.translation,
+        )
+    } else {
+        transform
+    }
+}