metal: support multi-gpu systems via copying

src/ifs/jay_screencast.rs

@@ -163,7 +163,9 @@ impl JayScreencast {
         let mut buffer = self.buffers.borrow_mut();
         for (idx, buffer) in buffer.deref_mut().iter_mut().enumerate() {
             if buffer.free {
-                buffer.fb.copy_texture(&self.client.state, texture, 0, 0);
+                buffer
+                    .fb
+                    .copy_texture(&self.client.state, texture, 0, 0, false);
                 self.client.event(Ready {
                     self_id: self.id,
                     idx: idx as _,

src/ifs/wl_output.rs

@@ -241,7 +241,13 @@ impl WlOutputGlobal {
                         continue;
                     }
                 };
-                fb.copy_texture(&self.state, tex, -capture.rect.x1(), -capture.rect.y1());
+                fb.copy_texture(
+                    &self.state,
+                    tex,
+                    -capture.rect.x1(),
+                    -capture.rect.y1(),
+                    false,
+                );
             }
             if capture.with_damage.get() {
                 capture.send_damage();