assert on unexpected image format from wlroots

src/frame/capturer/wlroots.rs

@@ -110,9 +110,10 @@ impl Capturer {
                     width,
                     height,
                     num_objects,
+                    format,
                     ..
                 } => {
-                    frame.set_metadata(width, height, num_objects);
+                    frame.set_metadata(width, height, num_objects, format);
                 }
 
                 Event::Object {

src/frame/object.rs

@@ -5,15 +5,17 @@ pub struct Object {
     pub width: u32,
     pub height: u32,
     pub num_objects: u32,
+    pub format: u32,
     pub fds: Vec<RawFd>,
     pub sizes: Vec<u32>,
 }
 
 impl Object {
-    pub fn set_metadata(&mut self, width: u32, height: u32, num_objects: u32) {
+    pub fn set_metadata(&mut self, width: u32, height: u32, num_objects: u32, format: u32) {
         self.width = width;
         self.height = height;
         self.num_objects = num_objects;
+        self.format = format;
         self.fds.resize(num_objects as usize, 0);
         self.sizes.resize(num_objects as usize, 0);
     }

src/frame/vulkan.rs

@@ -179,6 +179,10 @@ impl Vulkan {
             1, frame.num_objects,
             "Frames with multiple objects are not supported yet, use WLR_DRM_NO_MODIFIERS=1 as described in README and follow issue #8"
         );
+        assert_eq!(
+            875713112, frame.format,
+            "Frame with formats other than DRM_FORMAT_XRGB8888 are not supported yet (yours is {}). If you see this issue, please open a GitHub issue (unless there's one already open) and share your format value", frame.format
+        );
 
         if self.image.borrow().is_none() {
             self.init_image(frame)?;