Native wayland preview window

CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Added
 
+* Add `Preview.QTGL_WL`, a GPU-accelerated Qt preview that runs as a native Wayland client (as well as X11), avoiding XWayland. See `examples/preview_qtgl_wayland.py`.
+* Add `Preview.QTGL_WL_DIRECT`, a native-Wayland Qt preview that renders directly to the window surface (QOpenGLWindow), avoiding the FBO blit of `Preview.QTGL_WL` for higher throughput. See `examples/preview_qtgl_wayland_direct.py`.
+
 ### Changed
 
 ## 0.3.36 Beta Release 35

examples/preview_qtgl_wayland.py

@@ -0,0 +1,26 @@
+#!/usr/bin/python3
+
+# QtGlPreviewWayland is a GPU-accelerated Qt preview (like QtGlPreview) that
+# also works as a *native* Wayland client, not only through XWayland.
+#
+# QtGlPreview renders raw EGL onto the widget's native window, which only works
+# on X11; under a Wayland compositor it falls back to XWayland. QtGlPreviewWayland
+# instead renders through Qt's own OpenGL context (QOpenGLWidget), so it needs no
+# X server and composites natively. The zero-copy dmabuf import is unchanged.
+#
+# Select it with Preview.QTGL_WL. Prefer it when running under Wayland (e.g.
+# labwc) and you want to avoid XWayland; on X11 the regular Preview.QTGL is the
+# usual choice.
+
+import time
+
+from picamera2 import Picamera2, Preview
+
+picam2 = Picamera2()
+picam2.start_preview(Preview.QTGL_WL)
+
+preview_config = picam2.create_preview_configuration()
+picam2.configure(preview_config)
+
+picam2.start()
+time.sleep(5)

examples/preview_qtgl_wayland_direct.py

@@ -0,0 +1,24 @@
+#!/usr/bin/python3
+
+# QtGlPreviewWaylandDirect is like QtGlPreviewWayland (a native-Wayland,
+# GPU-accelerated Qt preview) but renders straight to the window surface using
+# a QOpenGLWindow, avoiding the QOpenGLWidget FBO -> window blit. This is the
+# fastest option, especially at high resolutions.
+#
+# Caveat: it uses a container/native window, which always stacks above sibling
+# Qt widgets and can't be clipped by non-rectangular masks. For a viewfinder
+# that fills its area this is fine (overlays are drawn inside the GL context);
+# apps that float Qt widgets over the preview should use Preview.QTGL_WL.
+
+import time
+
+from picamera2 import Picamera2, Preview
+
+picam2 = Picamera2()
+picam2.start_preview(Preview.QTGL_WL_DIRECT)
+
+preview_config = picam2.create_preview_configuration()
+picam2.configure(preview_config)
+
+picam2.start()
+time.sleep(5)

picamera2/picamera2.py

@@ -1,40 +1,41 @@
 #!/usr/bin/python3
 """picamera2 main class"""
 
 import atexit
 import contextlib
 import json
 import logging
 import os
 import selectors
 import sys
 import tempfile
 import threading
 import time
 from collections.abc import Callable
 from enum import Enum
 from functools import partial
 from typing import Any, Generic, Literal, Optional, TypedDict, TypeVar, Union, cast, overload
 
 import libcamera
 import numpy as np
 from libcamera import controls
 from numpy.typing import NDArray
 from PIL import Image
 
 import picamera2.formats as formats
 import picamera2.platform as Platform
 import picamera2.utils as utils
 from picamera2.allocators import DmaAllocator
 from picamera2.encoders import Encoder, H264Encoder, MJPEGEncoder, Quality
 from picamera2.outputs import FileOutput, PyavOutput
-from picamera2.previews import DrmPreview, NullPreview, QtGlPreview, QtPreview
+from picamera2.previews import (DrmPreview, NullPreview, QtGlPreview, QtGlPreviewWayland,
+                                QtGlPreviewWaylandDirect, QtPreview)
 
 from .configuration import CameraConfiguration
 from .controls import Controls
 from .job import Job
 from .request import CompletedRequest, Helpers
 from .sensor_format import SensorFormat
 
 STILL = libcamera.StreamRole.StillCapture
 RAW = libcamera.StreamRole.Raw
@@ -52,6 +53,8 @@
     DRM = DrmPreview
     QT = QtPreview
     QTGL = QtGlPreview
+    QTGL_WL = QtGlPreviewWayland
+    QTGL_WL_DIRECT = QtGlPreviewWaylandDirect
 
 
 class GlobalCameraInfo(TypedDict):

picamera2/previews/__init__.py

@@ -1,3 +1,3 @@
 from .drm_preview import DrmPreview
 from .null_preview import NullPreview
-from .qt_previews import QtGlPreview, QtPreview
+from .qt_previews import QtGlPreview, QtGlPreviewWayland, QtGlPreviewWaylandDirect, QtPreview