cross: OffsetDimSlice: impl indices() enumeration

crates/cross/src/dim/offset_dim_slice.rs

@@ -1,6 +1,6 @@
 use core::ops::{Index, IndexMut};
 
-use crate::dim::DimSlice;
+use crate::dim::{DimIter, DimSlice};
 use crate::vec::Vec3u;
 
 
@@ -13,6 +13,9 @@ impl<T> OffsetDimSlice<T> {
     pub fn new(offset: Vec3u, dim: Vec3u, items: T) -> Self {
         Self { offset, inner: DimSlice::new(dim, items) }
     }
+    pub fn indices(&self) -> OffsetDimIter {
+        OffsetDimIter::new(self.offset, self.inner.indices())
+    }
 }
 
 impl<T> Index<Vec3u> for OffsetDimSlice<T>
@@ -43,6 +46,26 @@ impl<T: IntoIterator> IntoIterator for OffsetDimSlice<T> {
     }
 }
 
+pub struct OffsetDimIter {
+    offset: Vec3u,
+    inner: DimIter,
+}
+
+impl OffsetDimIter {
+    fn new(offset: Vec3u, inner: DimIter) -> Self {
+        Self { offset, inner }
+    }
+}
+
+#[cfg(feature = "iter")]
+impl Iterator for OffsetDimIter {
+    type Item = Vec3u;
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next().map(|i| i + self.offset)
+    }
+}
+
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -87,7 +110,7 @@ mod test {
     }
 
     #[test]
-    fn dim_slice_into_iter() {
+    fn offset_dim_slice_into_iter() {
         let data = [1, 2, 3, 4];
         let s = OffsetDimSlice::new(Vec3u::new(1, 2, 3), Vec3u::new(2, 1, 2), &data);
         let mut i = s.into_iter();
@@ -99,7 +122,7 @@ mod test {
     }
 
     #[test]
-    fn dim_slice_into_iter_mut() {
+    fn offset_dim_slice_into_iter_mut() {
         let mut data = [1, 2, 3, 4];
         let s = OffsetDimSlice::new(Vec3u::new(1, 2, 3), Vec3u::new(2, 1, 2), &mut data);
         let mut i = s.into_iter();
@@ -111,4 +134,16 @@ mod test {
 
         assert_eq!(data, [10,2,30,4]);
     }
+
+    #[test]
+    fn offset_dim_slice_indices() {
+        let s = OffsetDimSlice::new(Vec3u::new(10, 20, 30), Vec3u::new(2, 1, 2), &[()]);
+        let mut i = s.indices();
+        assert_eq!(i.next().unwrap(), Vec3u::new(10, 20, 30));
+        assert_eq!(i.next().unwrap(), Vec3u::new(11, 20, 30));
+        assert_eq!(i.next().unwrap(), Vec3u::new(10, 20, 31));
+        assert_eq!(i.next().unwrap(), Vec3u::new(11, 20, 31));
+        assert_eq!(i.next(), None);
+        assert_eq!(i.next(), None);
+    }
 }