Use `link_libraries` instead of `add_defintions` to link against Qt 6.9
and newer to avoid un-expanded generator expressions from Qt cmake files
being appended to linker flags when building the HighGUI module.
The actual bug is likely in how Qt cmake files end up with these
un-expanded generator expressions in the first place — see discussion in
https://bugreports.qt.io/browse/QTBUG-134774 — but the recommended way
to link against the library is to use `link_libraries` anyway, so this
fix should do the trick.
Fixes issue #27223.
Missing include directories needed for wayland-util and xkbcommon #26563
See: #26561
### Pull Request Readiness Checklist
See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request
- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
Support OpenGL GTK3 New API #25822Fixes#20001
GSoC2024 Project
### Pull Request Readiness Checklist
See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request
- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
Highgui backend on top of Framebuffer #25661
### Pull Request Readiness Checklist
See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request
- [ x] I agree to contribute to the project under Apache 2 License.
- [ x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [ x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
Patch to opencv_extra has the same branch name.
- [ x] The feature is well documented and sample code can be built with the project CMake
Environment variables used:
OPENCV_UI_BACKEND - you need to add the value “FB”
OPENCV_UI_PRIORITY_FB - requires priority indication
OPENCV_HIGHGUI_FB_MODE={FB|XVFB|EMU} - mode of using Framebuffer (default "FB")
- FB - Linux Framebuffer
- XVFB - virtual Framebuffer
- EMU - emulation (images are not displayed)
OPENCV_HIGHGUI_FB_DEVICE (FRAMEBUFFER) - path to the Framebuffer file (default "/dev/fb0").
Examples of using:
sudo OPENCV_UI_BACKEND=FB ./opencv_test_highgui
sudo OPENCV_UI_PRIORITY_FB=1111 ./opencv_test_highgui
OPENCV_UI_BACKEND=FB OPENCV_HIGHGUI_FB_MODE=EMU ./opencv_test_highgui
sudo OPENCV_UI_BACKEND=FB OPENCV_HIGHGUI_FB_MODE=FB ./opencv_test_highgui
export DISPLAY=:99
Xvfb $DISPLAY -screen 0 1024x768x24 -fbdir /tmp/ -f /tmp/user.xvfb.auth&
sudo -u sipeed XAUTHORITY=/tmp/user.xvfb.auth x11vnc -display $DISPLAY -listen localhost&
DISPLAY=:0 gvncviewer localhost&
FRAMEBUFFER=/tmp/Xvfb_screen0 OPENCV_UI_BACKEND=FB OPENCV_HIGHGUI_FB_MODE=XVFB ./opencv_test_highgui
The Qt backend directly calls some OpenGL functions (glClear, glHint,
glViewport), but since OCV 4.5.5 the GL libraries are no longer part
of the global extra dependencies. When linking with "-Wl,--no-undefined"
this causes linker errors:
`opencv-4.5.5/modules/highgui/src/window_QT.cpp:3307: undefined reference to `glClear'`
Fixes: #21346
Related issues: #21299
- QGLWidget changed to QOpenGLWidget in window_QT.h for Qt6 using
typedef OpenCVQtWidgetBase for handling Qt version
- Implement Qt6/OpenGL functionality in window_QT.cpp
- Swap QGLWidget:: function calls for OpenCVQtWidgetBase:: function calls
- QGLWidget::updateGL deprecated, swap to QOpenGLWidget::update for Qt6
- Add preprocessor definition to detect Qt6 -- HAVE_QT6
- Add OpenGLWidgets to qdeps list in highgui CMakeLists.txt
- find_package CMake command added for locating Qt module OpenGLWidgets
- Added check that Qt6::OpenGLWidgets component is found. Shut off Qt-openGL functionality if not found.
The objective is to:
*Reduce greatly the number of lines of code in the Java codes;
*Make it easy for Java users to add a trackbar and show the results;
*Get the code more similar between C++, Java and Python, making the tutorials more uniform.
Atri Bhattacharya
Amir Hassan
Corentin Noël
Yoshiki Obinata
kozinove
Alexander Alekhin
Alexander Smorkalov
Suleyman TURKMEN
Joel Winarske
Stefan Brüns
Patrick Whalen
Christian Clauss
Stanislaw Halik
xhawk18
Tatsuro Shibamura
Alexander Alekhin
mevatron
tribta
Vladislav Sovrasov
Vadim Pisarevsky
Maksim Shabunin
Gregory Morse
Alexander Alekhin
Maxim Kostin