cv/video-frame, tracker/pt: add hidpi preview support

2 files changed, 29 insertions, 3 deletions

diff --git a/cv/video-widget.cpp b/cv/video-widget.cpp
index 4c9a73e6..f125bf76 100644
--- a/cv/video-widget.cpp
+++ b/cv/video-widget.cpp
@@ -85,8 +85,27 @@ void cv_video_widget::update_image(const QImage& img)
 void cv_video_widget::paintEvent(QPaintEvent*)
 {
     QMutexLocker foo(&mtx);
+
     QPainter painter(this);
+
+    double dpr = devicePixelRatioF();
+
+    int W = int(QWidget::width() * dpr);
+    int H = int(QWidget::height() * dpr);
+
     painter.drawImage(rect(), texture);
+
+    if (texture.width() != W || texture.height() != H)
+    {
+        texture = QImage(W, H, QImage::Format_ARGB32);
+        texture.setDevicePixelRatio(dpr);
+
+        width = W, height = H;
+
+        _frame = cv::Mat();
+        _frame2 = cv::Mat();
+        _frame3 = cv::Mat();
+    }
 }
 
 void cv_video_widget::update_and_repaint()
@@ -102,3 +121,10 @@ void cv_video_widget::update_and_repaint()
         repaint();
     }
 }
+
+void cv_video_widget::get_preview_size(int& w, int& h)
+{
+    QMutexLocker l(&mtx);
+
+    w = width, h = height;
+}
diff --git a/cv/video-widget.hpp b/cv/video-widget.hpp
index 7faddb49..15430e2f 100644
--- a/cv/video-widget.hpp
+++ b/cv/video-widget.hpp
@@ -31,9 +31,8 @@ public:
     cv_video_widget(QWidget *parent);
     void update_image(const cv::Mat& frame);
     void update_image(const QImage& image);
-
-    static constexpr inline int width = 320, height = 240;
-protected slots:
+    void get_preview_size(int& w, int& h);
+private slots:
     void paintEvent(QPaintEvent*) override;
     void update_and_repaint();
 private:
@@ -42,5 +41,6 @@ private:
     std::vector<unsigned char> vec;
     QTimer timer;
     cv::Mat _frame, _frame2, _frame3;
+    int width = 320, height = 240;
     bool freshp = false;
 };