ui: scale training image to fit window (#28454)

selfdrive/ui/qt/offroad/onboarding.cc

@@ -4,6 +4,7 @@
 #include <QPainter>
 #include <QQmlContext>
 #include <QQuickWidget>
+#include <QTransform>
 #include <QVBoxLayout>
 
 #include "common/util.h"
@@ -21,36 +22,54 @@ void TrainingGuide::mouseReleaseEvent(QMouseEvent *e) {
   }
   click_timer.restart();
 
-  if (boundingRect[currentIndex].contains(e->x(), e->y())) {
+  auto contains = [this](QRect r, const QPoint &pt) {
+    if (image.size() != image_raw_size) {
+      QTransform transform;
+      transform.translate((width()- image.width()) / 2.0, (height()- image.height()) / 2.0);
+      transform.scale(image.width() / (float)image_raw_size.width(), image.height() / (float)image_raw_size.height());
+      r= transform.mapRect(r);
+    }
+    return r.contains(pt);
+  };
+
+  if (contains(boundingRect[currentIndex], e->pos())) {
     if (currentIndex == 9) {
       const QRect yes = QRect(707, 804, 531, 164);
-      Params().putBool("RecordFront", yes.contains(e->x(), e->y()));
+      Params().putBool("RecordFront", contains(yes, e->pos()));
     }
     currentIndex += 1;
-  } else if (currentIndex == (boundingRect.size() - 2) && boundingRect.last().contains(e->x(), e->y())) {
+  } else if (currentIndex == (boundingRect.size() - 2) && contains(boundingRect.last(), e->pos())) {
     currentIndex = 0;
   }
 
   if (currentIndex >= (boundingRect.size() - 1)) {
     emit completedTraining();
   } else {
-    image.load(img_path + "step" + QString::number(currentIndex) + ".png");
     update();
   }
 }
 
 void TrainingGuide::showEvent(QShowEvent *event) {
   currentIndex = 0;
-  image.load(img_path + "step0.png");
   click_timer.start();
 }
 
+QImage TrainingGuide::loadImage(int id) {
+  QImage img(img_path + QString("step%1.png").arg(id));
+  image_raw_size = img.size();
+  if (image_raw_size != rect().size()) {
+    img = img.scaled(width(), height(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
+  }
+  return img;
+}
+
 void TrainingGuide::paintEvent(QPaintEvent *event) {
   QPainter painter(this);
 
   QRect bg(0, 0, painter.device()->width(), painter.device()->height());
   painter.fillRect(bg, QColor("#000000"));
 
+  image = loadImage(currentIndex);
   QRect rect(image.rect());
   rect.moveCenter(bg.center());
   painter.drawImage(rect.topLeft(), image);

selfdrive/ui/qt/offroad/onboarding.h

@@ -20,8 +20,10 @@ private:
   void showEvent(QShowEvent *event) override;
   void paintEvent(QPaintEvent *event) override;
   void mouseReleaseEvent(QMouseEvent* e) override;
+  QImage loadImage(int id);
 
   QImage image;
+  QSize image_raw_size;
   int currentIndex = 0;
 
   // Bounding boxes for each training guide step