common: aabb: area_weight fn

lib/common/src/aabb.rs

@@ -61,11 +61,11 @@ impl Aabb{
 	pub fn center(&self)->Planar64Vec3{
 		self.min.map_zip(self.max,|(min,max)|min.midpoint(max))
 	}
-	//probably use floats for area & volume because we don't care about precision
-	// pub fn area_weight(&self)->f32{
-	// 	let d=self.max-self.min;
-	// 	d.x*d.y+d.y*d.z+d.z*d.x
-	// }
+	#[inline]
+	pub fn area_weight(&self)->fixed_wide::fixed::Fixed<2,64>{
+		let d=self.max-self.min;
+		d.x*d.y+d.y*d.z+d.z*d.x
+	}
 	// pub fn volume(&self)->f32{
 	// 	let d=self.max-self.min;
 	// 	d.x*d.y*d.z