works, sorta, but blinks like crazy, cursor gets f-ed up...

interface/resources/qml/hifi/SpectatorCamera.qml

@@ -190,6 +190,7 @@ Rectangle {
             boxSize: 24;
             onClicked: {
                 sendToScript({method: (checked ? 'spectatorCameraOn' : 'spectatorCameraOff')});
+                spectatorCameraPreviewItem.ready = checked;
             }
         }
 
@@ -202,7 +203,10 @@ Rectangle {
             anchors.topMargin: 20;
             anchors.right: parent.right;
             Hifi.ResourceImageItem {
+                id: spectatorCameraPreviewItem;
                 anchors.fill: parent;
+                url: "resource://spectatorCameraFrame";
+                ready: false;
             }
         }
 

interface/src/ui/ResourceImageItem.cpp

@@ -8,11 +8,55 @@
 // See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+#include "Application.h"
 #include "ResourceImageItem.h"
 #include <QOpenGLFramebufferObjectFormat>
 #include <DependencyManager.h>
 #include <TextureCache.h>
 
+
+ResourceImageItem::ResourceImageItem(QQuickItem* parent) : QQuickFramebufferObject(parent) {
+    connect(&m_updateTimer, SIGNAL(timeout()), this, SLOT(update()));
+}
+
+void ResourceImageItem::setUrl(const QString& url) {
+    if (url != m_url) {
+        m_url = url;
+        update();
+    }
+}
+
+void ResourceImageItem::setReady(bool ready) {
+    if (ready != m_ready) {
+        m_ready = ready;
+        if (m_ready) {
+            m_updateTimer.start(1000);
+        } else {
+            m_updateTimer.stop();
+        }
+        update();
+    }
+}
+
+void ResourceImageItemRenderer::synchronize(QQuickFramebufferObject* item) {
+    ResourceImageItem* resourceImageItem = static_cast<ResourceImageItem*>(item);
+    bool urlChanged = false;
+    if( _url != resourceImageItem->getUrl()) {
+        _url = resourceImageItem->getUrl();
+        urlChanged = true;
+    }
+    bool readyChanged = false;
+    if (_ready != resourceImageItem->getReady()) {
+        _ready = resourceImageItem->getReady();
+        readyChanged = true;
+    }
+    _window = resourceImageItem->window();
+    qDebug() << "synchronize called!!!!!!!";
+    if (_ready && !_url.isNull() && !_url.isEmpty() && (readyChanged || urlChanged)) {
+        _networkTexture = DependencyManager::get<TextureCache>()->getTexture(_url);
+    }
+}
+
 QOpenGLFramebufferObject* ResourceImageItemRenderer::createFramebufferObject(const QSize& size) {
     QOpenGLFramebufferObjectFormat format;
     format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
@@ -20,9 +64,12 @@ QOpenGLFramebufferObject* ResourceImageItemRenderer::createFramebufferObject(con
 }
 
 void ResourceImageItemRenderer::render() {
-    auto texture = DependencyManager::get<TextureCache>()->getTexture(QUrl("resource://spectatorCameraFrame"));
+    qDebug() << "render called!!!!!!!!!!!!!!";
+    if (_networkTexture && _ready) {
+        auto texture = _networkTexture->getGPUTexture();
         if (texture) {
-        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture->getGPUTexture(), 0);
+            qApp->getActiveDisplayPlugin()->copyTextureToQuickFramebuffer(texture, framebufferObject());
+            _window->resetOpenGLState();
+        }
     }
-
 }

interface/src/ui/ResourceImageItem.h

@@ -13,15 +13,37 @@
 #define hifi_ResourceImageItem_h
 
 #include <QQuickFramebufferObject>
-#include <QOpenGLFunctions>
+#include <QQuickWindow>
+#include <QTimer>
 
-class ResourceImageItemRenderer : public QQuickFramebufferObject::Renderer, protected QOpenGLFunctions {
+class ResourceImageItemRenderer : public QQuickFramebufferObject::Renderer {
+public:
     QOpenGLFramebufferObject* createFramebufferObject(const QSize& size);
+    void synchronize(QQuickFramebufferObject* item);
     void render();
+private:
+    bool _ready;
+    QString _url;
+    NetworkTexturePointer _networkTexture;
+    QQuickWindow* _window;
 };
 
 class ResourceImageItem : public QQuickFramebufferObject {
+    Q_OBJECT
+    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 { return new ResourceImageItemRenderer; }
+private:
+    QString m_url;
+    bool m_ready { false };
+    QTimer m_updateTimer; // TODO: something more clever
 };
 
 #endif // hifi_ResourceImageItem_h

libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp

@@ -16,6 +16,7 @@
 
 #include <QtOpenGL/QGLWidget>
 #include <QtGui/QImage>
+#include <QOpenGLFramebufferObject>
 #if defined(Q_OS_MAC)
 #include <OpenGL/CGLCurrent.h>
 #endif
@@ -820,3 +821,20 @@ void OpenGLDisplayPlugin::updateCompositeFramebuffer() {
         _compositeFramebuffer = gpu::FramebufferPointer(gpu::Framebuffer::create("OpenGLDisplayPlugin::composite", gpu::Element::COLOR_RGBA_32, renderSize.x, renderSize.y));
     }
 }
+
+void OpenGLDisplayPlugin::copyTextureToQuickFramebuffer(gpu::TexturePointer source, QOpenGLFramebufferObject* target) {
+    auto glBackend = const_cast<OpenGLDisplayPlugin&>(*this).getGLBackend();
+    withMainThreadContext([&] {
+        GLuint sourceTexture = glBackend->getTextureID(source);
+        GLuint targetTexture = target->texture();
+        GLuint fbo { 0 };
+        glCreateFramebuffers(1, &fbo);
+        glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
+        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, sourceTexture, 0);
+        glCopyTextureSubImage2D(targetTexture, 0, 0, 0, 0, 0, target->width(), target->height());
+        glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+        glDeleteFramebuffers(1, &fbo);
+        glDeleteTextures(1, &fbo);
+    });
+}
+

libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h

@@ -78,6 +78,8 @@ public:
     // Three threads, one for rendering, one for texture transfers, one reserved for the GL driver
     int getRequiredThreadCount() const override { return 3; }
 
+    void copyTextureToQuickFramebuffer(gpu::TexturePointer source, QOpenGLFramebufferObject* target);
+
 protected:
     friend class PresentThread;
 

libraries/plugins/src/plugins/DisplayPlugin.h

@@ -25,6 +25,8 @@
 
 #include "Plugin.h"
 
+class QOpenGLFramebufferObject;
+
 class QImage;
 
 enum Eye {
@@ -208,6 +210,8 @@ public:
     // Hardware specific stats
     virtual QJsonObject getHardwareStats() const { return QJsonObject(); }
 
+    virtual void copyTextureToQuickFramebuffer(gpu::TexturePointer source, QOpenGLFramebufferObject* target) = 0;
+
     uint32_t presentCount() const { return _presentedFrameIndex; }
     // Time since last call to incrementPresentCount (only valid if DEBUG_PAINT_DELAY is defined)
     int64_t getPaintDelayUsecs() const;