Make sure cameraInit change does not clear cache

Author: Fabien Servant

src/qtAliceVision/AsyncFetcher.hpp

@@ -67,6 +67,11 @@ class AsyncFetcher : public QObject, public QRunnable
     */
     void stopAsync();
 
+    bool isAsync() const 
+    {
+        return _isAsynchroneous;
+    }
+
     /**
      * @brief get the cache content size in bytes
      * @return the cache content size in bytes

src/qtAliceVision/FloatImageViewer.cpp

@@ -185,11 +185,13 @@ QVector4D FloatImageViewer::pixelValueAt(int x, int y)
 {
     if (!_image)
     {
+        std::cout << "error no image" << std::endl;
         // qInfo() << "[QtAliceVision] FloatImageViewer::pixelValueAt(" << x << ", " << y << ") => no valid image";
         return QVector4D(0.0, 0.0, 0.0, 0.0);
     }
     else if (x < 0 || x >= _image->width() || y < 0 || y >= _image->height())
     {
+        std::cout << "error out of image " << x << " " << _image->width() << " " << y << " " << _image->height()<< std::endl;
         // qInfo() << "[QtAliceVision] FloatImageViewer::pixelValueAt(" << x << ", " << y << ") => out of range";
         return QVector4D(0.0, 0.0, 0.0, 0.0);
     }

src/qtAliceVision/SequenceCache.cpp

@@ -24,6 +24,13 @@ SequenceCache::SequenceCache(QObject* parent)
     _maxMemory = static_cast<size_t>(cacheRam);  
 
     _fetcher.setAutoDelete(false); 
+    
+    //Cache does not exist
+    //Let's create a new one !
+    {
+        image::ImageCache::uptr cache = std::make_unique<image::ImageCache>(_maxMemory, image::EImageColorSpace::LINEAR);
+        _fetcher.setCache(std::move(cache));
+    }
 }
 
 SequenceCache::~SequenceCache()
@@ -34,16 +41,11 @@ SequenceCache::~SequenceCache()
 
 void SequenceCache::setSequence(const QVariantList& paths)
 {
+    bool isAsync = _fetcher.isAsync();
+
     _fetcher.stopAsync();
     _threadPool.waitForDone();
 
-    //On changing sequence, the cache become totally invalid
-    //Let's create a new one !
-    {
-        image::ImageCache::uptr cache = std::make_unique<image::ImageCache>(_maxMemory, image::EImageColorSpace::LINEAR);
-        _fetcher.setCache(std::move(cache));
-    }
-
     //Convert to string
     std::vector<std::string> sequence;
     for (const auto & item : paths)
@@ -53,6 +55,9 @@ void SequenceCache::setSequence(const QVariantList& paths)
 
     //Assign sequence to fetcher
     _fetcher.setSequence(sequence);
+
+    //Restart if needed
+    setAsyncFetching(isAsync);
 }
 
 void SequenceCache::setResizeRatio(double ratio)