Fix trivial build errors on linux. Also support Qt 5.5.

3 files changed, 5 insertions, 1 deletions

diff --git a/cv/camera-dialog.cpp b/cv/camera-dialog.cpp
index 05161cb1..f2cdf9db 100644
--- a/cv/camera-dialog.cpp
+++ b/cv/camera-dialog.cpp
@@ -20,12 +20,14 @@ void camera_dialog::maybe_grab_frame(cv::VideoCapture& cap)
     }
 }
 
+#ifdef _WIN32
 void camera_dialog::init_com_threading()
 {
     HRESULT hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
     if (FAILED(hr))
         qDebug() << "failed CoInitializeEx" << hr << "code" << GetLastError();
 }
+#endif
 
 camera_dialog::~camera_dialog() {}
 
diff --git a/cv/camera-dialog.hpp b/cv/camera-dialog.hpp
index 08462e92..15ae2bc9 100644
--- a/cv/camera-dialog.hpp
+++ b/cv/camera-dialog.hpp
@@ -16,13 +16,13 @@
 #endif
 
 #ifdef _WIN32
-#   include <opencv2/videoio.hpp>
 #   include <QTimer>
 #   include <objbase.h>
 #   include <winerror.h>
 #   include <windows.h>
 #endif
 
+#include <opencv2/videoio.hpp>
 #include <QMutex>
 
 class camera_dialog
diff --git a/gui/main.cpp b/gui/main.cpp
index e708dc9d..c07a65ac 100644
--- a/gui/main.cpp
+++ b/gui/main.cpp
@@ -116,7 +116,9 @@ int main(int argc, char** argv)
     QCoreApplication::addLibraryPath(".");
 #endif
 
+#if QT_VERSION >= 0x050600 // flag introduced in QT 5.6. It is non-essential so might as well allow compilation on older systems.
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+#endif
     QApplication::setAttribute(Qt::AA_X11InitThreads, true);
     QApplication app(argc, argv);