Make the QGlPicamera2 widget work through XWayland

Signed-off-by: David Plowman <[email protected]>

apps/app_capture2.py

@@ -9,7 +9,7 @@
                              QVBoxLayout, QWidget)
 
 from picamera2 import Picamera2
-from picamera2.previews.qt import QGlPicamera2
+from picamera2.previews.qt import QGlPicamera2, QPicamera2
 
 
 def post_callback(request):

picamera2/__init__.py

@@ -9,6 +9,10 @@
 from .picamera2 import Picamera2, Preview
 from .request import CompletedRequest, MappedArray
 
+if os.environ.get("XDG_SESSION_TYPE", None) == "wayland":
+    # The code here works through the X wayland layer, but not otherwise.
+    os.environ["QT_QPA_PLATFORM"] = "xcb"
+
 
 def _set_configuration_file(filename):
     dirs = [

picamera2/previews/q_gl_picamera2.py

@@ -2,12 +2,9 @@
 import threading
 import time
 
-from libcamera import Transform
-from PyQt5.QtCore import QSocketNotifier, Qt, pyqtSignal, pyqtSlot
-from PyQt5.QtWidgets import QWidget
-
 os.environ["PYOPENGL_PLATFORM"] = "egl"
 
+from libcamera import Transform
 from OpenGL.EGL.EXT.image_dma_buf_import import *
 from OpenGL.EGL.KHR.image import *
 from OpenGL.EGL.VERSION.EGL_1_0 import *
@@ -18,6 +15,8 @@
 from OpenGL.GLES2.OES.EGL_image_external import *
 from OpenGL.GLES2.VERSION.GLES2_2_0 import *
 from OpenGL.GLES3.VERSION.GLES3_3_0 import *
+from PyQt5.QtCore import QSocketNotifier, Qt, pyqtSignal, pyqtSlot
+from PyQt5.QtWidgets import QWidget
 
 from picamera2.previews.gl_helpers import *
 
@@ -201,10 +200,13 @@ def init_gl(self):
             }
         """
 
-        self.program_image = shaders.compileProgram(
-            shaders.compileShader(vertShaderSrc_image, GL_VERTEX_SHADER),
-            shaders.compileShader(fragShaderSrc_image, GL_FRAGMENT_SHADER)
-        )
+        vertex_shader = shaders.compileShader(vertShaderSrc_image, GL_VERTEX_SHADER),
+        # For some reason I seem to be getting a 1 element tuple back. Absolutely no clue why.
+        if isinstance(vertex_shader, tuple):
+            vertex_shader = vertex_shader[0]
+        fragment_shader = shaders.compileShader(fragShaderSrc_image, GL_FRAGMENT_SHADER)
+        self.program_image = shaders.compileProgram(vertex_shader, fragment_shader)
+
         self.program_overlay = shaders.compileProgram(
             shaders.compileShader(vertShaderSrc_overlay, GL_VERTEX_SHADER),
             shaders.compileShader(fragShaderSrc_overlay, GL_FRAGMENT_SHADER)
@@ -369,6 +371,10 @@ def repaint(self, completed_request, update_viewport=False):
 
     def render_request(self, completed_request):
         """Draw the camera image using Qt and OpenGL/GLES."""
+        # For reasons not terribly well understood, eglMakeCurrent hangs in the X-Wayland world if the
+        # window is being closed. This appears to stop it.
+        if not self.isVisible():
+            return
         if self.title_function is not None:
             self.setWindowTitle(self.title_function(completed_request.get_metadata()))
         with self.lock:

picamera2/previews/qt.py

@@ -10,6 +10,6 @@
 _log = getLogger(__name__)
 
 try:
-    from .q_gl_picamera2 import EglState, QGlPicamera2
+    from .q_gl_picamera2 import QGlPicamera2
 except Exception:
     _log.warning("OpenGL will not be available")