fix for jitter and not rendering in tablet

interface/src/ui/ResourceImageItem.cpp

@@ -18,34 +18,36 @@
 
 #include <DependencyManager.h>
 
-ResourceImageItem::ResourceImageItem(QQuickItem* parent) : QQuickFramebufferObject(parent) {
-    connect(&m_updateTimer, SIGNAL(timeout()), this, SLOT(onUpdateTimer()));
-}
-
-void ResourceImageItem::onUpdateTimer() {
-    update();
-}
-
 void ResourceImageItem::setUrl(const QString& url) {
     if (url != m_url) {
         m_url = url;
+        update();
     }
-    update();
 }
 
 void ResourceImageItem::setReady(bool ready) {
     if (ready != m_ready) {
         m_ready = ready;
-        if (m_ready) {
+        update();
-            // 10 HZ for now.  Also this serves as a small
+    }
-            // delay before getting the network texture, which
+}
-            // helps a lot.  TODO: find better way.
+
-            m_updateTimer.start(100);
+void ResourceImageItemRenderer::onUpdateTimer() {
+    if (_ready && _networkTexture && _networkTexture->isLoaded()) {
+        if(_fboMutex.tryLock()) {
+            invalidateFramebufferObject();
+            qApp->getActiveDisplayPlugin()->copyTextureToQuickFramebuffer(_networkTexture, _copyFbo, &_fenceSync);
+            _fboMutex.unlock();
         } else {
-            m_updateTimer.stop();
+            qDebug() << "couldn't get a lock, using last frame";
-            update();
         }
     }
+
+    update();
+}
+
+ResourceImageItemRenderer::ResourceImageItemRenderer() : QQuickFramebufferObject::Renderer() {
+    connect(&_updateTimer, SIGNAL(timeout()), this, SLOT(onUpdateTimer()));
 }
 
 void ResourceImageItemRenderer::synchronize(QQuickFramebufferObject* item) {
@@ -68,18 +70,11 @@ void ResourceImageItemRenderer::synchronize(QQuickFramebufferObject* item) {
         _networkTexture = DependencyManager::get<TextureCache>()->getTexture(_url);
     }
 
-    if (_ready && _networkTexture && _networkTexture->isLoaded()) {
+    if (_ready && !_updateTimer.isActive()) {
-        if(_fboMutex.tryLock()) {
+        _updateTimer.start(100);
-            invalidateFramebufferObject();
+    } else if (!_ready && _updateTimer.isActive()) {
-            qApp->getActiveDisplayPlugin()->copyTextureToQuickFramebuffer(_networkTexture, _copyFbo, &_fenceSync);
+        _updateTimer.stop();
-            _fboMutex.unlock();
-        } else {
-            qDebug() << "couldn't get a lock, using last frame";
-        }
-
     }
-    glFlush();
-
 }
 
 QOpenGLFramebufferObject* ResourceImageItemRenderer::createFramebufferObject(const QSize& size) {
@@ -90,28 +85,6 @@ QOpenGLFramebufferObject* ResourceImageItemRenderer::createFramebufferObject(con
     return new QOpenGLFramebufferObject(size, format);
 }
 
-/*
-// this is helpful to look for problems without the confusion of the framebufer stuff
-void ResourceImageItemRenderer::render() {
-    qDebug() << "rendering";
-    static int colorInt = 0;
-    float red = (float)((colorInt++ % 50)/(float)50);
-    glClearColor(red, 0.0f, 0.0f, 0.5f + red/2.0f);
-    glClear(GL_COLOR_BUFFER_BIT);
-    glFlush();
-    update();
-    //_window->resetOpenGLState();
-    // we only want to call Renderer::update once per timer tick, and
-    // so waiting on the fenceSync and resetting it does that
-    auto f = QOpenGLContext::currentContext()->extraFunctions();
-    if (_fenceSync) {
-        f->glWaitSync(_fenceSync, 0, GL_TIMEOUT_IGNORED);
-        f->glDeleteSync(_fenceSync);
-        _fenceSync = 0;
-        update();
-    }
-}
-*/
 void ResourceImageItemRenderer::render() {
     auto f = QOpenGLContext::currentContext()->extraFunctions();
     bool doUpdate = false;
@@ -136,4 +109,5 @@ void ResourceImageItemRenderer::render() {
         }
     }
     glFlush();
+    _window->resetOpenGLState();
 }

interface/src/ui/ResourceImageItem.h

@@ -18,8 +18,10 @@
 
 #include <TextureCache.h>
 
-class ResourceImageItemRenderer : public QQuickFramebufferObject::Renderer {
+class ResourceImageItemRenderer : public QObject, public QQuickFramebufferObject::Renderer {
+    Q_OBJECT
 public:
+    ResourceImageItemRenderer();
     QOpenGLFramebufferObject* createFramebufferObject(const QSize& size) override;
     void synchronize(QQuickFramebufferObject* item) override;
     void render() override;
@@ -32,6 +34,9 @@ private:
     QMutex _fboMutex;
     QOpenGLFramebufferObject* _copyFbo;
     GLsync _fenceSync { 0 };
+    QTimer _updateTimer;
+public slots:
+    void onUpdateTimer();
 };
 
 class ResourceImageItem : public QQuickFramebufferObject {
@@ -39,20 +44,15 @@ class ResourceImageItem : public QQuickFramebufferObject {
     Q_PROPERTY(QString url READ getUrl WRITE setUrl)
     Q_PROPERTY(bool ready READ getReady WRITE setReady)
 public:
-    ResourceImageItem(QQuickItem* parent = Q_NULLPTR);
     QString getUrl() const { return m_url; }
     void setUrl(const QString& url);
     bool getReady() const { return m_ready; }
     void setReady(bool ready);
     QQuickFramebufferObject::Renderer* createRenderer() const override { return new ResourceImageItemRenderer; }
 
-public slots:
-    void onUpdateTimer();
-
 private:
     QString m_url;
     bool m_ready { false };
-    QTimer m_updateTimer; // TODO: something more clever
 
 };