path: root/src/plugins/platforms
diff options
authorAllan Sandfeld Jensen <>2016-01-06 11:01:39 +0100
committerAllan Sandfeld Jensen <>2016-01-08 19:08:43 +0000
commit1bcfc3de7586ddb9f5d1b778b97b26ae3dc9584d (patch)
tree66571c15008a0978c8b2335d668656075a504086 /src/plugins/platforms
parentc04cf29b78f3f5747c58dd89ca21523e387ee3ac (diff)
Use backing store formats with alpha
We depend on being able to punch holes in the backing store when integrating with FBO elements. To do that we need a format with an alpha channel. This was only working previously because RGB32 didn't mask when filling or when converting to ARGB32_PM, but other formats didn't. Also unifies the logic for getting alpha versions of QImage formats. Task-number: QTBUG-50281 Change-Id: Ied1325f60e2b67d9ea2dfa9701b06fc2231ebfca Reviewed-by: Laszlo Agocs <>
Diffstat (limited to 'src/plugins/platforms')
1 files changed, 4 insertions, 0 deletions
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
index 1825a463d0..006df320fe 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
@@ -51,6 +51,7 @@
#include <qscreen.h>
#include <QtGui/private/qhighdpiscaling_p.h>
#include <qpa/qplatformgraphicsbuffer.h>
+#include <private/qimage_p.h>
#include <algorithm>
@@ -172,6 +173,9 @@ QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QI
qWarning() << "QXcbBackingStore: Error while marking the shared memory segment to be destroyed";
+ if (QImage::toPixelFormat(format).alphaUsage() == QPixelFormat::IgnoresAlpha)
+ format = qt_alphaVersionForPainting(format);
m_qimage = QImage( (uchar*) m_xcb_image->data, m_xcb_image->width, m_xcb_image->height, m_xcb_image->stride, format);
m_graphics_buffer = new QXcbShmGraphicsBuffer(&m_qimage);