Present new frame only when damaged in iced_tiny_skia

tiny_skia/src/backend.rs

@@ -50,7 +50,7 @@ impl Backend {
         viewport: &Viewport,
         background_color: Color,
         overlay: &[T],
-    ) {
+    ) -> bool {
         let physical_size = viewport.physical_size();
 
         let damage = if self.last_background_color == background_color
@@ -62,7 +62,7 @@ impl Backend {
         };
 
         if damage.is_empty() {
-            return;
+            return false;
         }
 
         self.last_primitives = primitives.to_vec();
@@ -179,6 +179,8 @@ impl Backend {
 
         #[cfg(feature = "svg")]
         self.vector_pipeline.trim_cache();
+
+        true
     }
 
     fn draw_primitive(

tiny_skia/src/window/compositor.rs

@@ -106,7 +106,7 @@ pub fn present<Theme, T: AsRef<str>>(
 ) -> Result<(), compositor::SurfaceError> {
     let physical_size = viewport.physical_size();
 
-    backend.draw(
+    let drawn = backend.draw(
         &mut tiny_skia::PixmapMut::from_bytes(
             bytemuck::cast_slice_mut(&mut surface.buffer),
             physical_size.width,
@@ -120,11 +120,13 @@ pub fn present<Theme, T: AsRef<str>>(
         overlay,
     );
 
-    surface.window.set_buffer(
-        &surface.buffer,
-        physical_size.width as u16,
-        physical_size.height as u16,
-    );
+    if drawn {
+        surface.window.set_buffer(
+            &surface.buffer,
+            physical_size.width as u16,
+            physical_size.height as u16,
+        );
+    }
 
     Ok(())
 }