works with Qt5

code/3rd_QGLViewer/CMakeLists.txt

@@ -5,28 +5,7 @@ endif()
 project(libQGLViewer LANGUAGES CXX VERSION 2.9.1)
 cmake_minimum_required(VERSION 3.16)
 
-# Qt6 minimum compiler version
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-
-# Find includes in corresponding build directories
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-# Instruct CMake to run moc automatically when needed.
-set(CMAKE_AUTOMOC ON)
-# Instruct CMake to run uic automatically when needed.
-set(CMAKE_AUTOUIC ON)
-
-# This will find the Qt files.
-find_package(Qt6 COMPONENTS Core Widgets Xml OpenGL OpenGLWidgets)
-if (Qt6_FOUND)
-    message(STATUS "Building with Qt6")
-    set(QtLibs Qt::Core Qt::Widgets Qt::Xml Qt::OpenGL Qt::OpenGLWidgets)
-else()
-    find_package(Qt5 COMPONENTS Core Widgets Xml OpenGL REQUIRED)
-    message(STATUS "Building with Qt5")
-    set(QtLibs Qt5Core Qt5OpenGL Qt5Widgets Qt5Xml)
-endif()
-
+include(../cmake/UseQt.cmake)
 
 find_package(OpenGL REQUIRED)
 

code/3rd_QGLViewer/QGLViewer/camera.h

@@ -2,6 +2,7 @@
 #define QGLVIEWER_CAMERA_H
 
 #include "../basic/canvas.h"
+#include <QMap>
 #include "keyFrameInterpolator.h"
 class QGLViewer;
 

code/3rd_QGLViewer/QGLViewer/qglviewer.cpp

@@ -659,20 +659,28 @@ void QGLViewer::setCamera(Camera *const camera) {
   disconnect(this->camera()->frame(), SIGNAL(manipulated()), this,
              SLOT(update()));
   disconnect(this->camera()->frame(), SIGNAL(spun()), this, SLOT(update()));
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)) // The screen() function was introduced in the QWidget class starting from Qt 5.14.
   disconnect(screen(), SIGNAL(physicalDotsPerInchChanged(qreal)), this->camera(), SLOT(setDevicePixelRatio(qreal)));
+#endif
   connectAllCameraKFIInterpolatedSignals(false);
 
   camera_ = camera;
 
   camera->setSceneRadius(sceneRadius());
   camera->setSceneCenter(sceneCenter());
   camera->setScreenWidthAndHeight(width(), height());
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)) // The screen() function was introduced in the QWidget class starting from Qt 5.14.
   camera->setDevicePixelRatio(screen()->devicePixelRatio());
+#else
+    camera->setDevicePixelRatio(devicePixelRatioF());
+#endif
 
   // Connect camera frame to this viewer.
   connect(camera->frame(), SIGNAL(manipulated()), SLOT(update()));
   connect(camera->frame(), SIGNAL(spun()), SLOT(update()));
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)) // The screen() function was introduced in the QWidget class starting from Qt 5.14.
   connect(screen(), SIGNAL(physicalDotsPerInchChanged(qreal)), camera, SLOT(setDevicePixelRatio(qreal)));
+#endif
   connectAllCameraKFIInterpolatedSignals();
 
   previousCameraZClippingCoefficient_ = this->camera()->zClippingCoefficient();

code/3rd_QGLViewer/QGLViewer/saveSnapshot.cpp

@@ -303,7 +303,11 @@ class ImageInterface : public QDialog, public Ui::ImageInterface {
 // Returns false in case of problem.
 bool QGLViewer::saveImageSnapshot(const QString &fileName) {
   static ImageInterface *imageInterface = nullptr;
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)) // The screen() function was introduced in the QWidget class starting from Qt 5.14.
   qreal devicePixelRatio = screen()->devicePixelRatio();
+#else
+  qreal devicePixelRatio = devicePixelRatioF();
+#endif
   qreal dipWidth = devicePixelRatio * width();
   qreal dipHeight = devicePixelRatio * height();
 

code/PolyFit/CMakeLists.txt

@@ -1,31 +1,7 @@
 get_filename_component(PROJECT_NAME ${CMAKE_CURRENT_SOURCE_DIR} NAME)
 project(${PROJECT_NAME})
 
-
-# ------------------------------------------------------------------------------
-# Qt
-# ------------------------------------------------------------------------------
-
-# Find includes in corresponding build directories
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-# Instruct CMake to run moc automatically when needed.
-set(CMAKE_AUTOMOC ON)
-# Instruct CMake to run uic automatically when needed.
-set(CMAKE_AUTOUIC ON)
-# Instruct CMake to run rcc automatically when needed.
-set(CMAKE_AUTORCC ON)
-
-# This will find the Qt files.
-find_package(Qt6 COMPONENTS Core Widgets Xml OpenGL OpenGLWidgets)
-if (Qt6_FOUND)
-    message(STATUS "Building with Qt6")
-    set(QtLibs Qt::Core Qt::Widgets Qt::Xml Qt::OpenGL Qt::OpenGLWidgets)
-else()
-    find_package(Qt5 COMPONENTS Core Gui OpenGL Widgets Xml REQUIRED)
-    message(STATUS "Building with Qt5")
-    set(QtLibs Qt5Core Qt5Gui Qt5OpenGL Qt5Widgets Qt5Xml)
-endif()
-
+include(../cmake/UseQt.cmake)
 
 set(${PROJECT_NAME}_HEADERS
     main_window.h

code/cmake/UseQt.cmake

@@ -0,0 +1,80 @@
+# *************************************************************************
+#      Copyright (C) 2015 Liangliang Nan <[email protected]>
+#      https://3d.bk.tudelft.nl/liangliang/
+#
+#      This file is part of Easy3D. If it is useful in your research/work,
+#      I would be grateful if you show your appreciation by citing it:
+#      ------------------------------------------------------------------
+#           Liangliang Nan.
+#           Easy3D: a lightweight, easy-to-use, and efficient C++ library
+#           for processing and rendering 3D data.
+#           Journal of Open Source Software, 6(64), 3255, 2021.
+#      ------------------------------------------------------------------
+#
+#      Easy3D is free software; you can redistribute it and/or modify
+#      it under the terms of the GNU General Public License Version 3
+#      as published by the Free Software Foundation.
+#
+#      Easy3D is distributed in the hope that it will be useful,
+#      but WITHOUT ANY WARRANTY; without even the implied warranty of
+#      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+#      GNU General Public License for more details.
+#
+#      You should have received a copy of the GNU General Public License
+#      along with this program. If not, see <http://www.gnu.org/licenses/>.
+# *************************************************************************
+
+
+# ------------------------------------------------------------------------------
+# This file sets up Qt for CMake. When Qt6 was setup successfully, Qt6_FOUND
+# will be set. If Qt6 is not found, it will try to find Qt5. If Qt5 is found,
+# Qt5_FOUND will be set. If both Qt6 and Qt5 are not found, it will stop the
+# configuration and show an error message.
+# If either Qt6 or Qt5 is found, it will set QtLibs to the corresponding Qt
+# libraries, e.g., Qt5Core, Qt5Gui, Qt5Widgets, Qt5OpenGL, Qt5Xml, etc.
+#
+# To use Qt in your program, you only need to include this file and specifying
+# Qt libraries to link against, e.g.,
+#       ------------------------------------------------------------------------
+#           project(${PROJECT_NAME})
+#           include( ../cmake/UseQt5.cmake )
+#           add_executable(${PROJECT_NAME}, main.cpp)
+#           target_link_libraries(${PROJECT_NAME} ${QtLibs})
+#       ------------------------------------------------------------------------
+# NOTE: 'UseQt.cmake' must be included after you define your project but before
+#       'add_executable()' or 'add_library()'.
+#
+#   The recommended way to specify libraries and headers with CMake is to use the
+#   target_link_libraries command. This command automatically adds appropriate
+#   include directories, compile definitions, the position-independent-code flag,
+#   and links to the qtmain.lib library on Windows.
+# ------------------------------------------------------------------------------
+
+
+# Qt6 minimum compiler version
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Find includes in corresponding build directories
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+# Instruct CMake to run moc automatically when needed.
+set(CMAKE_AUTOMOC ON)
+# Instruct CMake to run uic automatically when needed.
+set(CMAKE_AUTOUIC ON)
+# Instruct CMake to run rcc automatically when needed.
+set(CMAKE_AUTORCC ON)
+
+# This will find the Qt files.
+find_package(Qt6 COMPONENTS Core Widgets OpenGL OpenGLWidgets Xml QUIET)
+if (Qt6_FOUND)
+    message(STATUS "Found Qt6 version: ${Qt5Core_VERSION}")
+    set(QtLibs Qt::Core Qt::Widgets Qt::OpenGL Qt::OpenGLWidgets Qt::Xml)
+else()
+    find_package(Qt5 COMPONENTS Core Widgets OpenGL Xml QUIET)
+    if (Qt5_FOUND)
+        message(STATUS "Found Qt5 version: ${Qt5Core_VERSION}")
+        set(QtLibs Qt5::Core Qt5::Widgets Qt5::OpenGL Qt5::Xml)
+    else()
+        message(FATAL_ERROR "Qt is required, either Qt6 or Qt5, but both cannot be found")
+    endif()
+endif()