From 6c8e07c3771ad35c2d01b924095d4f51d8a638f3 Mon Sep 17 00:00:00 2001
From: KIU Shueng Chuan <nixchuan@gmail.com>
Date: Thu, 11 Feb 2021 09:02:33 +0800
Subject: [PATCH 1/2] use 64-bits qimage size for PyQt5 5.15

PyQt5 5.15 has both methods sizeInBytes() (64-bits) and byteCount()
(32-bits)
the previous formulation would use 32-bits qimage size for PyQt5 5.15.
---
 pyqtgraph/functions.py | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/pyqtgraph/functions.py b/pyqtgraph/functions.py
index 0281aacd..d7ddae0c 100644
--- a/pyqtgraph/functions.py
+++ b/pyqtgraph/functions.py
@@ -1358,21 +1358,23 @@ def imageToArray(img, copy=False, transpose=True):
     The array will have shape (width, height, (b,g,r,a)).
     """
     fmt = img.format()
-    ptr = img.bits()
-    if QT_LIB in ['PySide', 'PySide2', 'PySide6']:
-        arr = np.frombuffer(ptr, dtype=np.ubyte)
-    else:
+    img_ptr = img.bits()
+
+    if QT_LIB.startswith('PyQt'):
+        # sizeInBytes() was introduced in Qt 5.10
+        # however PyQt5 5.12 will fail with:
+        #   "TypeError: QImage.sizeInBytes() is a private method"
+        # note that sizeInBytes() works fine with:
+        #   PyQt5 5.15, PySide2 5.12, PySide2 5.15
         try:
-            # removed in Qt6
-            nbytes = img.byteCount()
-        except AttributeError:
-            # introduced in Qt 5.10
-            # however Python 3.7 + PyQt5-5.12 in the CI fails with
-            # "TypeError: QImage.sizeInBytes() is a private method"
+            # 64-bits size
             nbytes = img.sizeInBytes()
-        ptr.setsize(nbytes)
-        arr = np.asarray(ptr)
-    
+        except (TypeError, AttributeError):
+            # 32-bits size
+            nbytes = img.byteCount()
+        img_ptr.setsize(nbytes)
+
+    arr = np.frombuffer(img_ptr, dtype=np.ubyte)
     arr = arr.reshape(img.height(), img.width(), 4)
     if fmt == img.Format_RGB32:
         arr[...,3] = 255

From 659392d4bb3322c0215942b99a4117fb409d9233 Mon Sep 17 00:00:00 2001
From: KIU Shueng Chuan <nixchuan@gmail.com>
Date: Thu, 11 Feb 2021 09:35:48 +0800
Subject: [PATCH 2/2] don't rely on QImage being non-const

the previous formulation creates an ndarray and then creates an QImage
over it w/o copying. this relies on the QImage thus created being
non-const.

if the QImage was (unintentionally) created as const, the subsequent
QPainter render on the const QImage would trigger a COW. i.e. the
original underlying ndarray wouldn't be updated.

this is only an issue for PyQt bindings where const QImages can be
created.
---
 pyqtgraph/tests/image_testing.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pyqtgraph/tests/image_testing.py b/pyqtgraph/tests/image_testing.py
index 1fcfeb53..bfb8dc0f 100644
--- a/pyqtgraph/tests/image_testing.py
+++ b/pyqtgraph/tests/image_testing.py
@@ -137,12 +137,14 @@ def assertImageApproved(image, standardFile, message=None, **kwargs):
         QtGui.QApplication.processEvents()
 
         graphstate = scenegraphState(w, standardFile)
-        image = np.zeros((w.height(), w.width(), 4), dtype=np.ubyte)
-        qimg = fn.makeQImage(image, alpha=True, copy=False, transpose=False)
+        qimg = QtGui.QImage(w.size(), QtGui.QImage.Format.Format_ARGB32)
+        qimg.fill(QtCore.Qt.GlobalColor.transparent)
         painter = QtGui.QPainter(qimg)
         w.render(painter)
         painter.end()
         
+        image = fn.imageToArray(qimg, copy=False, transpose=False)
+
         # transpose BGRA to RGBA
         image = image[..., [2, 1, 0, 3]]