system/ui: implement CameraView widget (#35185)

* initial commit

* run at 60hz, nonblock

* graceful cleanup

* re-position

* rename

---------

Co-authored-by: Cameron Clough <cameronjclough@gmail.com>

system/ui/widgets/cameraview.py

@@ -0,0 +1,87 @@
+import pyray as rl
+from msgq.visionipc import VisionIpcClient, VisionStreamType
+from openpilot.system.ui.lib.application import gui_app
+
+FRAME_FRAGMENT_SHADER = """
+#version 330 core
+in vec2 fragTexCoord; uniform sampler2D texture0, texture1; out vec4 fragColor;
+void main() {
+  float y = texture(texture0, fragTexCoord).r;
+  vec2 uv = texture(texture1, fragTexCoord).ra - 0.5;
+  fragColor = vec4(y + 1.402*uv.y, y - 0.344*uv.x - 0.714*uv.y, y + 1.772*uv.x, 1.0);
+}"""
+
+
+class CameraView:
+  def __init__(self, name: str, stream_type: VisionStreamType):
+    self.client = VisionIpcClient(name, stream_type, False)
+    self.shader = rl.load_shader_from_memory(rl.ffi.NULL, FRAME_FRAGMENT_SHADER)
+    self.texture_y: rl.Texture | None = None
+    self.texture_uv: rl.Texture | None = None
+    self.frame = None
+
+  def close(self):
+    self._clear_textures()
+    if self.shader and self.shader.id:
+      rl.unload_shader(self.shader)
+
+  def render(self, rect: rl.Rectangle):
+    if not self._ensure_connection():
+      return
+
+    buffer = self.client.recv(timeout_ms=0)
+    self.frame = buffer if buffer else self.frame
+    if not self.frame or not self.texture_y or not self.texture_uv:
+      return
+
+    y_data = self.frame.data[: self.frame.uv_offset]
+    uv_data = self.frame.data[self.frame.uv_offset :]
+
+    rl.update_texture(self.texture_y, rl.ffi.cast("void *", y_data.ctypes.data))
+    rl.update_texture(self.texture_uv, rl.ffi.cast("void *", uv_data.ctypes.data))
+
+    # Calculate scaling to maintain aspect ratio
+    scale = min(rect.width / self.frame.width, rect.height / self.frame.height)
+    x_offset = rect.x + (rect.width - (self.frame.width * scale)) / 2
+    y_offset = rect.y + (rect.height - (self.frame.height * scale)) / 2
+    src_rect = rl.Rectangle(0, 0, float(self.frame.width), float(self.frame.height))
+    dst_rect = rl.Rectangle(x_offset, y_offset, self.frame.width * scale, self.frame.height * scale)
+
+    rl.begin_shader_mode(self.shader)
+    rl.set_shader_value_texture(self.shader, rl.get_shader_location(self.shader, "texture1"), self.texture_uv)
+    rl.draw_texture_pro(self.texture_y, src_rect, dst_rect, rl.Vector2(0, 0), 0.0, rl.WHITE)
+    rl.end_shader_mode()
+
+  def _ensure_connection(self) -> bool:
+    if not self.client.is_connected():
+      self.frame = None
+      if not self.client.connect(False) or not self.client.num_buffers:
+        return False
+
+      self._clear_textures()
+      self.texture_y = rl.load_texture_from_image(rl.Image(None, int(self.client.stride),
+        int(self.client.height), 1, rl.PixelFormat.PIXELFORMAT_UNCOMPRESSED_GRAYSCALE))
+      self.texture_uv = rl.load_texture_from_image(rl.Image(None, int(self.client.stride // 2),
+        int(self.client.height // 2), 1, rl.PixelFormat.PIXELFORMAT_UNCOMPRESSED_GRAY_ALPHA))
+    return True
+
+  def _clear_textures(self):
+    if self.texture_y and self.texture_y.id:
+      rl.unload_texture(self.texture_y)
+    if self.texture_uv and self.texture_uv.id:
+      rl.unload_texture(self.texture_uv)
+
+if __name__ == "__main__":
+  gui_app.init_window("watch3")
+  road_camera_view = CameraView("camerad", VisionStreamType.VISION_STREAM_ROAD)
+  driver_camera_view = CameraView("camerad", VisionStreamType.VISION_STREAM_DRIVER)
+  wide_road_camera_view = CameraView("camerad", VisionStreamType.VISION_STREAM_WIDE_ROAD)
+  try:
+    for _ in gui_app.render():
+      road_camera_view.render(rl.Rectangle(gui_app.width // 4, 0, gui_app.width // 2, gui_app.height // 2))
+      driver_camera_view.render(rl.Rectangle(0, gui_app.height // 2, gui_app.width // 2, gui_app.height // 2))
+      wide_road_camera_view.render(rl.Rectangle(gui_app.width // 2, gui_app.height // 2, gui_app.width // 2, gui_app.height // 2))
+  finally:
+    road_camera_view.close()
+    driver_camera_view.close()
+    wide_road_camera_view.close()