ui: fill the bg with disengaged color if no frame

selfdrive/ui/onroad/augmented_road_view.py

@@ -28,6 +28,7 @@
 class AugmentedRoadView(CameraView):
   def __init__(self, stream_type: VisionStreamType = VisionStreamType.VISION_STREAM_ROAD):
     super().__init__("camerad", stream_type)
+    self._set_placeholder_color(BORDER_COLORS[UIStatus.DISENGAGED])
 
     self.device_camera: DeviceCameraConfig | None = None
     self.view_from_calib = view_frame_from_device_frame.copy()

selfdrive/ui/onroad/cameraview.py

@@ -74,6 +74,8 @@ def __init__(self, name: str, stream_type: VisionStreamType):
     self.egl_images: dict[int, EGLImage] = {}
     self.egl_texture: rl.Texture | None = None
 
+    self._placeholder_color : rl.Color | None = None
+
     # Initialize EGL for zero-copy rendering on TICI
     if TICI:
       if not init_egl():
@@ -84,6 +86,10 @@ def __init__(self, name: str, stream_type: VisionStreamType):
       self.egl_texture = rl.load_texture_from_image(temp_image)
       rl.unload_image(temp_image)
 
+  def _set_placeholder_color(self, color: rl.Color):
+    """Set a placeholder color to be drawn when no frame is available."""
+    self._placeholder_color = color
+
   def switch_stream(self, stream_type: VisionStreamType) -> None:
     if self._stream_type != stream_type:
       cloudlog.debug(f'switching stream from {self._stream_type} to {stream_type}')
@@ -130,6 +136,7 @@ def _calc_frame_matrix(self, rect: rl.Rectangle) -> np.ndarray:
 
   def render(self, rect: rl.Rectangle):
     if not self._ensure_connection():
+      self._draw_placeholder(rect)
       return
 
     # Try to get a new buffer without blocking
@@ -139,6 +146,7 @@ def render(self, rect: rl.Rectangle):
       self.frame = buffer
 
     if not self.frame:
+      self._draw_placeholder(rect)
       return
 
     transform = self._calc_frame_matrix(rect)
@@ -163,6 +171,10 @@ def render(self, rect: rl.Rectangle):
     else:
       self._render_textures(src_rect, dst_rect)
 
+  def _draw_placeholder(self, rect: rl.Rectangle):
+    if self._placeholder_color:
+      rl.draw_rectangle_rec(rect, self._placeholder_color)
+
   def _render_egl(self, src_rect: rl.Rectangle, dst_rect: rl.Rectangle) -> None:
     """Render using EGL for direct buffer access"""
     if self.frame is None or self.egl_texture is None: