Change render functions to accept iterators

src/niri.rs

@@ -2499,6 +2499,7 @@ impl Niri {
                 // FIXME: Hidden / embedded / metadata cursor
                 let elements = elements
                     .get_or_insert_with(|| self.render::<GlesRenderer>(renderer, output, true));
+                let elements = elements.iter().rev();
 
                 if let Err(err) = render_to_dmabuf(renderer, dmabuf, size, scale, elements) {
                     error!("error rendering to dmabuf: {err:?}");
@@ -2577,8 +2578,9 @@ impl Niri {
 
                 let scale = Scale::from(output.current_scale().fractional_scale());
                 let elements = self.render::<GlesRenderer>(renderer, &output, true);
+                let elements = elements.iter().rev();
 
-                let res = render_to_texture(renderer, size, scale, Fourcc::Abgr8888, &elements);
+                let res = render_to_texture(renderer, size, scale, Fourcc::Abgr8888, elements);
                 let screenshot = match res {
                     Ok((texture, _)) => texture,
                     Err(err) => {
@@ -2607,7 +2609,8 @@ impl Niri {
 
         let scale = Scale::from(output.current_scale().fractional_scale());
         let elements = self.render::<GlesRenderer>(renderer, output, true);
-        let pixels = render_to_vec(renderer, size, scale, Fourcc::Abgr8888, &elements)?;
+        let elements = elements.iter().rev();
+        let pixels = render_to_vec(renderer, size, scale, Fourcc::Abgr8888, elements)?;
 
         self.save_screenshot(size, pixels)
             .context("error saving screenshot")
@@ -2632,7 +2635,8 @@ impl Niri {
             scale,
             1.,
         );
-        let pixels = render_to_vec(renderer, size, scale, Fourcc::Abgr8888, &elements)?;
+        let elements = elements.iter().rev();
+        let pixels = render_to_vec(renderer, size, scale, Fourcc::Abgr8888, elements)?;
 
         self.save_screenshot(size, pixels)
             .context("error saving screenshot")
@@ -2730,12 +2734,13 @@ impl Niri {
         let size = transform.transform_size(size);
 
         let elements = self.render::<GlesRenderer>(renderer, &output, include_pointer);
+        let elements = elements.iter().rev();
         let pixels = render_to_vec(
             renderer,
             size,
             Scale::from(f64::from(output_scale)),
             Fourcc::Abgr8888,
-            &elements,
+            elements,
         )?;
 
         let path = make_screenshot_path(&self.config.borrow())

src/render_helpers/mod.rs

@@ -15,7 +15,7 @@ pub fn render_to_texture(
     size: Size<i32, Physical>,
     scale: Scale<f64>,
     fourcc: Fourcc,
-    elements: &[impl RenderElement<GlesRenderer>],
+    elements: impl Iterator<Item = impl RenderElement<GlesRenderer>>,
 ) -> anyhow::Result<(GlesTexture, SyncPoint)> {
     let _span = tracy_client::span!();
 
@@ -34,7 +34,7 @@ pub fn render_to_texture(
         .render(size, Transform::Normal)
         .context("error starting frame")?;
 
-    for element in elements.iter().rev() {
+    for element in elements {
         let src = element.src();
         let dst = element.geometry(scale);
 
@@ -55,7 +55,7 @@ pub fn render_and_download(
     size: Size<i32, Physical>,
     scale: Scale<f64>,
     fourcc: Fourcc,
-    elements: &[impl RenderElement<GlesRenderer>],
+    elements: impl Iterator<Item = impl RenderElement<GlesRenderer>>,
 ) -> anyhow::Result<GlesMapping> {
     let _span = tracy_client::span!();
 
@@ -74,7 +74,7 @@ pub fn render_to_vec(
     size: Size<i32, Physical>,
     scale: Scale<f64>,
     fourcc: Fourcc,
-    elements: &[impl RenderElement<GlesRenderer>],
+    elements: impl Iterator<Item = impl RenderElement<GlesRenderer>>,
 ) -> anyhow::Result<Vec<u8>> {
     let _span = tracy_client::span!();
 
@@ -92,7 +92,7 @@ pub fn render_to_dmabuf(
     dmabuf: smithay::backend::allocator::dmabuf::Dmabuf,
     size: Size<i32, Physical>,
     scale: Scale<f64>,
-    elements: &[impl RenderElement<GlesRenderer>],
+    elements: impl Iterator<Item = impl RenderElement<GlesRenderer>>,
 ) -> anyhow::Result<()> {
     let _span = tracy_client::span!();
 
@@ -103,7 +103,7 @@ pub fn render_to_dmabuf(
         .render(size, Transform::Normal)
         .context("error starting frame")?;
 
-    for element in elements.iter().rev() {
+    for element in elements {
         let src = element.src();
         let dst = element.geometry(scale);