feat: Adjust zoom speed based on distance for consistent feel

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/Camera.cpp

@@ -44,7 +44,13 @@ void Camera::wheelEvent(QWheelEvent* event, const QVector3D& worldPos)
 {
     QPoint numDegrees = event->angleDelta() / 8;
     if (!numDegrees.isNull()) {
-        float zoomAmount = numDegrees.y() / 5.0f;
+        // Make zoom speed proportional to distance, with a minimum speed and a cap.
+        // The factors are chosen to match the original zoom speed at the default zoom level.
+        float dist = -m_zoom;
+        dist = qMin(dist, 200.0f); // Cap distance to avoid crazy fast zoom out.
+        float zoomFactor = dist * 0.009f + 0.02f;
+        float zoomAmount = numDegrees.y() * zoomFactor;
+
         float oldZoom = m_zoom;
         float newZoom = oldZoom + zoomAmount;