Cleanup: Separate the sub-tree layering out of QtQuick into the scene graph

This basically renames QQuickShaderEffectTexture to QSGDefaultLayer and
introduces QSGLayer as interface to be used. QQuickShaderEffectTexture is
generic for the scene graph and has no QtQuick dependencies. The interface
separation allows scene graph backends to customize layers.

Change-Id: I9a7f37addaa4b80a34ff9a1456b0cb9b16d4e9f3
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

5 files changed, 11 insertions, 507 deletions

diff --git a/src/quick/items/context2d/qquickcanvascontext_p.h b/src/quick/items/context2d/qquickcanvascontext_p.h
index 2d8fbb5f85..8988ea9105 100644
--- a/src/quick/items/context2d/qquickcanvascontext_p.h
+++ b/src/quick/items/context2d/qquickcanvascontext_p.h
@@ -49,7 +49,7 @@
 QT_BEGIN_NAMESPACE
 
 class QQuickCanvasItem;
-class QSGDynamicTexture;
+class QSGLayer;
 
 class QQuickCanvasContextPrivate;
 class QQuickCanvasContext : public QObject
diff --git a/src/quick/items/qquickitemgrabresult.cpp b/src/quick/items/qquickitemgrabresult.cpp
index 93b9261c44..f5d72bbd3a 100644
--- a/src/quick/items/qquickitemgrabresult.cpp
+++ b/src/quick/items/qquickitemgrabresult.cpp
@@ -91,7 +91,7 @@ public:
 
     QPointer<QQuickItem> item;
     QPointer<QQuickWindow> window;
-    QQuickShaderEffectTexture *texture;
+    QSGLayer *texture;
     QSizeF itemSize;
     QSize textureSize;
 };
@@ -228,7 +228,8 @@ void QQuickItemGrabResult::setup()
         return;
     }
 
-    d->texture = new QQuickShaderEffectTexture(d->item);
+    QSGRenderContext *rc = QQuickWindowPrivate::get(d->window.data())->context;
+    d->texture = rc->sceneGraphContext()->createLayer(rc);
     d->texture->setItem(QQuickItemPrivate::get(d->item)->itemNode());
     d->itemSize = QSizeF(d->item->width(), d->item->height());
 }
diff --git a/src/quick/items/qquickshadereffectnode.cpp b/src/quick/items/qquickshadereffectnode.cpp
index cefb006648..3f7938c386 100644
--- a/src/quick/items/qquickshadereffectnode.cpp
+++ b/src/quick/items/qquickshadereffectnode.cpp
@@ -418,7 +418,7 @@ void QQuickShaderEffectMaterial::updateTextures() const
 {
     for (int i = 0; i < textureProviders.size(); ++i) {
         if (QSGTextureProvider *provider = textureProviders.at(i)) {
-            if (QSGDynamicTexture *texture = qobject_cast<QSGDynamicTexture *>(provider->texture()))
+            if (QSGLayer *texture = qobject_cast<QSGLayer *>(provider->texture()))
                 texture->updateTexture();
         }
     }
diff --git a/src/quick/items/qquickshadereffectsource.cpp b/src/quick/items/qquickshadereffectsource.cpp
index 2b42a01fc1..f027e044e1 100644
--- a/src/quick/items/qquickshadereffectsource.cpp
+++ b/src/quick/items/qquickshadereffectsource.cpp
@@ -54,44 +54,6 @@
 
 QT_BEGIN_NAMESPACE
 
-DEFINE_BOOL_CONFIG_OPTION(qmlFboOverlay, QML_FBO_OVERLAY)
-DEFINE_BOOL_CONFIG_OPTION(qmlFboFlushBeforeDetach, QML_FBO_FLUSH_BEFORE_DETACH)
-
-namespace
-{
-    class BindableFbo : public QSGBindable
-    {
-    public:
-        BindableFbo(QOpenGLFramebufferObject *fbo, QSGDepthStencilBuffer *depthStencil);
-        virtual ~BindableFbo();
-        virtual void bind() const;
-    private:
-        QOpenGLFramebufferObject *m_fbo;
-        QSGDepthStencilBuffer *m_depthStencil;
-    };
-
-    BindableFbo::BindableFbo(QOpenGLFramebufferObject *fbo, QSGDepthStencilBuffer *depthStencil)
-        : m_fbo(fbo)
-        , m_depthStencil(depthStencil)
-    {
-    }
-
-    BindableFbo::~BindableFbo()
-    {
-        if (qmlFboFlushBeforeDetach())
-            QOpenGLContext::currentContext()->functions()->glFlush();
-        if (m_depthStencil)
-            m_depthStencil->detach();
-    }
-
-    void BindableFbo::bind() const
-    {
-        m_fbo->bind();
-        if (m_depthStencil)
-            m_depthStencil->attach();
-    }
-}
-
 class QQuickShaderEffectSourceTextureProvider : public QSGTextureProvider
 {
     Q_OBJECT
@@ -113,7 +75,7 @@ public:
         return sourceTexture;
     }
 
-    QQuickShaderEffectTexture *sourceTexture;
+    QSGLayer *sourceTexture;
 
     QSGTexture::Filtering mipmapFiltering;
     QSGTexture::Filtering filtering;
@@ -122,379 +84,10 @@ public:
 };
 #include "qquickshadereffectsource.moc"
 
-QQuickShaderEffectTexture::QQuickShaderEffectTexture(QQuickItem *shaderSource)
-    : QSGDynamicTexture()
-    , m_item(0)
-    , m_shaderSourceNode(0)
-    , m_device_pixel_ratio(1)
-    , m_format(GL_RGBA)
-    , m_renderer(0)
-    , m_fbo(0)
-    , m_secondaryFbo(0)
-    , m_transparentTexture(0)
-#ifdef QSG_DEBUG_FBO_OVERLAY
-    , m_debugOverlay(0)
-#endif
-    , m_context(QQuickItemPrivate::get(shaderSource)->sceneGraphRenderContext())
-    , m_mipmap(false)
-    , m_live(true)
-    , m_recursive(false)
-    , m_dirtyTexture(true)
-    , m_multisamplingChecked(false)
-    , m_multisampling(false)
-    , m_grab(false)
-{
-}
-
-QQuickShaderEffectTexture::~QQuickShaderEffectTexture()
-{
-    invalidated();
-}
-
-void QQuickShaderEffectTexture::invalidated()
-{
-    delete m_renderer;
-    m_renderer = 0;
-    delete m_fbo;
-    delete m_secondaryFbo;
-    m_fbo = m_secondaryFbo = 0;
-#ifdef QSG_DEBUG_FBO_OVERLAY
-    delete m_debugOverlay;
-    m_debugOverlay = 0;
-#endif
-    if (m_transparentTexture) {
-        QOpenGLContext::currentContext()->functions()->glDeleteTextures(1, &m_transparentTexture);
-        m_transparentTexture = 0;
-    }
-}
-
-void QQuickShaderEffectTexture::markDirtyTextureLater()
-{
-    QCoreApplication::postEvent(this, new QEvent(QEvent::User));
-}
-
-void QQuickShaderEffectTexture::customEvent(QEvent *)
-{
-    markDirtyTexture();
-}
-
-int QQuickShaderEffectTexture::textureId() const
-{
-    return m_fbo ? m_fbo->texture() : 0;
-}
-
-bool QQuickShaderEffectTexture::hasAlphaChannel() const
-{
-    return m_format != GL_RGB;
-}
-
-bool QQuickShaderEffectTexture::hasMipmaps() const
-{
-    return m_mipmap;
-}
-
-
-void QQuickShaderEffectTexture::bind()
-{
-#ifndef QT_NO_DEBUG
-    if (!m_recursive && m_fbo && ((m_multisampling && m_secondaryFbo->isBound()) || m_fbo->isBound()))
-        qWarning("ShaderEffectSource: \'recursive\' must be set to true when rendering recursively.");
-#endif
-    QOpenGLFunctions *funcs = QOpenGLContext::currentContext()->functions();
-    if (!m_fbo && m_format == GL_RGBA) {
-        if (m_transparentTexture == 0) {
-            funcs->glGenTextures(1, &m_transparentTexture);
-            funcs->glBindTexture(GL_TEXTURE_2D, m_transparentTexture);
-            const uint zero = 0;
-            funcs->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, &zero);
-        } else {
-            funcs->glBindTexture(GL_TEXTURE_2D, m_transparentTexture);
-        }
-    } else {
-        funcs->glBindTexture(GL_TEXTURE_2D, m_fbo ? m_fbo->texture() : 0);
-        updateBindOptions();
-    }
-}
-
-bool QQuickShaderEffectTexture::updateTexture()
-{
-    bool doGrab = (m_live || m_grab) && m_dirtyTexture;
-    if (doGrab)
-        grab();
-    if (m_grab)
-        emit scheduledUpdateCompleted();
-    m_grab = false;
-    return doGrab;
-}
-
-void QQuickShaderEffectTexture::setHasMipmaps(bool mipmap)
-{
-    if (mipmap == m_mipmap)
-        return;
-    m_mipmap = mipmap;
-    if (m_mipmap && m_fbo && !m_fbo->format().mipmap())
-        markDirtyTexture();
-}
-
-
-void QQuickShaderEffectTexture::setItem(QSGNode *item)
-{
-    if (item == m_item)
-        return;
-    m_item = item;
-
-    if (m_live && !m_item) {
-        delete m_fbo;
-        delete m_secondaryFbo;
-        m_fbo = m_secondaryFbo = 0;
-        m_depthStencilBuffer.clear();
-    }
-
-    markDirtyTexture();
-}
-
-void QQuickShaderEffectTexture::setRect(const QRectF &rect)
-{
-    if (rect == m_rect)
-        return;
-    m_rect = rect;
-    markDirtyTexture();
-}
-
-void QQuickShaderEffectTexture::setSize(const QSize &size)
-{
-    if (size == m_size)
-        return;
-    m_size = size;
-
-    if (m_live && m_size.isNull()) {
-        delete m_fbo;
-        delete m_secondaryFbo;
-        m_fbo = m_secondaryFbo = 0;
-        m_depthStencilBuffer.clear();
-    }
-
-    markDirtyTexture();
-}
-
-void QQuickShaderEffectTexture::setFormat(GLenum format)
-{
-    if (format == m_format)
-        return;
-    m_format = format;
-    markDirtyTexture();
-}
-
-void QQuickShaderEffectTexture::setLive(bool live)
-{
-    if (live == m_live)
-        return;
-    m_live = live;
-
-    if (m_live && (!m_item || m_size.isNull())) {
-        delete m_fbo;
-        delete m_secondaryFbo;
-        m_fbo = m_secondaryFbo = 0;
-        m_depthStencilBuffer.clear();
-    }
-
-    markDirtyTexture();
-}
-
-void QQuickShaderEffectTexture::scheduleUpdate()
-{
-    if (m_grab)
-        return;
-    m_grab = true;
-    if (m_dirtyTexture) {
-        emit updateRequested();
-        if (m_shaderSourceNode)
-            m_shaderSourceNode->markDirty(QSGNode::DirtyMaterial);
-    }
-}
-
-void QQuickShaderEffectTexture::setRecursive(bool recursive)
-{
-    m_recursive = recursive;
-}
-
-void QQuickShaderEffectTexture::markDirtyTexture()
-{
-    m_dirtyTexture = true;
-    if (m_live || m_grab) {
-        emit updateRequested();
-        if (m_shaderSourceNode)
-            m_shaderSourceNode->markDirty(QSGNode::DirtyMaterial);
-    }
-}
-
-void QQuickShaderEffectTexture::grab()
-{
-    if (!m_item || m_size.isNull()) {
-        delete m_fbo;
-        delete m_secondaryFbo;
-        m_fbo = m_secondaryFbo = 0;
-        m_depthStencilBuffer.clear();
-        m_dirtyTexture = false;
-        return;
-    }
-    QSGNode *root = m_item;
-    while (root->firstChild() && root->type() != QSGNode::RootNodeType)
-        root = root->firstChild();
-    if (root->type() != QSGNode::RootNodeType)
-        return;
-
-    if (!m_renderer) {
-        m_renderer = m_context->createRenderer();
-        connect(m_renderer, SIGNAL(sceneGraphChanged()), this, SLOT(markDirtyTextureLater()));
-    }
-    m_renderer->setDevicePixelRatio(m_device_pixel_ratio);
-    m_renderer->setRootNode(static_cast<QSGRootNode *>(root));
-
-    QOpenGLFunctions *funcs = QOpenGLContext::currentContext()->functions();
-    bool deleteFboLater = false;
-    if (!m_fbo || m_fbo->size() != m_size || m_fbo->format().internalTextureFormat() != m_format
-        || (!m_fbo->format().mipmap() && m_mipmap))
-    {
-        if (!m_multisamplingChecked) {
-            if (m_context->openglContext()->format().samples() <= 1) {
-                m_multisampling = false;
-            } else {
-                const QSet<QByteArray> extensions = m_context->openglContext()->extensions();
-                m_multisampling = extensions.contains(QByteArrayLiteral("GL_EXT_framebuffer_multisample"))
-                    && extensions.contains(QByteArrayLiteral("GL_EXT_framebuffer_blit"));
-            }
-            m_multisamplingChecked = true;
-        }
-        if (m_multisampling) {
-            // Don't delete the FBO right away in case it is used recursively.
-            deleteFboLater = true;
-            delete m_secondaryFbo;
-            QOpenGLFramebufferObjectFormat format;
-
-            format.setInternalTextureFormat(m_format);
-            format.setSamples(m_context->openglContext()->format().samples());
-            m_secondaryFbo = new QOpenGLFramebufferObject(m_size, format);
-            m_depthStencilBuffer = m_context->depthStencilBufferForFbo(m_secondaryFbo);
-        } else {
-            QOpenGLFramebufferObjectFormat format;
-            format.setInternalTextureFormat(m_format);
-            format.setMipmap(m_mipmap);
-            if (m_recursive) {
-                deleteFboLater = true;
-                delete m_secondaryFbo;
-                m_secondaryFbo = new QOpenGLFramebufferObject(m_size, format);
-                funcs->glBindTexture(GL_TEXTURE_2D, m_secondaryFbo->texture());
-                updateBindOptions(true);
-                m_depthStencilBuffer = m_context->depthStencilBufferForFbo(m_secondaryFbo);
-            } else {
-                delete m_fbo;
-                delete m_secondaryFbo;
-                m_fbo = new QOpenGLFramebufferObject(m_size, format);
-                m_secondaryFbo = 0;
-                funcs->glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
-                updateBindOptions(true);
-                m_depthStencilBuffer = m_context->depthStencilBufferForFbo(m_fbo);
-            }
-        }
-    }
-
-    if (m_recursive && !m_secondaryFbo) {
-        // m_fbo already created, m_recursive was just set.
-        Q_ASSERT(m_fbo);
-        Q_ASSERT(!m_multisampling);
-
-        m_secondaryFbo = new QOpenGLFramebufferObject(m_size, m_fbo->format());
-        funcs->glBindTexture(GL_TEXTURE_2D, m_secondaryFbo->texture());
-        updateBindOptions(true);
-    }
-
-    // Render texture.
-    root->markDirty(QSGNode::DirtyForceUpdate); // Force matrix, clip and opacity update.
-    m_renderer->nodeChanged(root, QSGNode::DirtyForceUpdate); // Force render list update.
-
-#ifdef QSG_DEBUG_FBO_OVERLAY
-    if (qmlFboOverlay()) {
-        if (!m_debugOverlay)
-            m_debugOverlay = new QSGSimpleRectNode();
-        m_debugOverlay->setRect(QRectF(0, 0, m_size.width(), m_size.height()));
-        m_debugOverlay->setColor(QColor(0xff, 0x00, 0x80, 0x40));
-        root->appendChildNode(m_debugOverlay);
-    }
-#endif
-
-    m_dirtyTexture = false;
-
-    m_renderer->setDeviceRect(m_size);
-    m_renderer->setViewportRect(m_size);
-    QRectF mirrored(m_rect.left(), m_rect.bottom(), m_rect.width(), -m_rect.height());
-    m_renderer->setProjectionMatrixToRect(mirrored);
-    m_renderer->setClearColor(Qt::transparent);
-
-    if (m_multisampling) {
-        m_renderer->renderScene(BindableFbo(m_secondaryFbo, m_depthStencilBuffer.data()));
-
-        if (deleteFboLater) {
-            delete m_fbo;
-            QOpenGLFramebufferObjectFormat format;
-            format.setInternalTextureFormat(m_format);
-            format.setAttachment(QOpenGLFramebufferObject::NoAttachment);
-            format.setMipmap(m_mipmap);
-            format.setSamples(0);
-            m_fbo = new QOpenGLFramebufferObject(m_size, format);
-            funcs->glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
-            updateBindOptions(true);
-        }
-
-        QRect r(QPoint(), m_size);
-        QOpenGLFramebufferObject::blitFramebuffer(m_fbo, r, m_secondaryFbo, r);
-    } else {
-        if (m_recursive) {
-            m_renderer->renderScene(BindableFbo(m_secondaryFbo, m_depthStencilBuffer.data()));
-
-            if (deleteFboLater) {
-                delete m_fbo;
-                QOpenGLFramebufferObjectFormat format;
-                format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
-                format.setInternalTextureFormat(m_format);
-                format.setMipmap(m_mipmap);
-                m_fbo = new QOpenGLFramebufferObject(m_size, format);
-                funcs->glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
-                updateBindOptions(true);
-            }
-            qSwap(m_fbo, m_secondaryFbo);
-        } else {
-            m_renderer->renderScene(BindableFbo(m_fbo, m_depthStencilBuffer.data()));
-        }
-    }
-
-    if (m_mipmap) {
-        funcs->glBindTexture(GL_TEXTURE_2D, textureId());
-        funcs->glGenerateMipmap(GL_TEXTURE_2D);
-    }
-
-    root->markDirty(QSGNode::DirtyForceUpdate); // Force matrix, clip, opacity and render list update.
-
-#ifdef QSG_DEBUG_FBO_OVERLAY
-    if (qmlFboOverlay())
-        root->removeChildNode(m_debugOverlay);
-#endif
-    if (m_recursive)
-        markDirtyTexture(); // Continuously update if 'live' and 'recursive'.
-}
-
-QImage QQuickShaderEffectTexture::toImage() const
-{
-    if (m_fbo)
-        return m_fbo->toImage();
-
-    return QImage();
-}
-
 class QQuickShaderEffectSourceCleanup : public QRunnable
 {
 public:
-    QQuickShaderEffectSourceCleanup(QQuickShaderEffectTexture *t, QQuickShaderEffectSourceTextureProvider *p)
+    QQuickShaderEffectSourceCleanup(QSGLayer *t, QQuickShaderEffectSourceTextureProvider *p)
         : texture(t)
         , provider(p)
     {}
@@ -502,7 +95,7 @@ public:
         delete texture;
         delete provider;
     }
-    QQuickShaderEffectTexture *texture;
+    QSGLayer *texture;
     QQuickShaderEffectSourceTextureProvider *provider;
 };
 
@@ -642,7 +235,8 @@ void QQuickShaderEffectSource::ensureTexture()
                "QQuickShaderEffectSource::ensureTexture",
                "Cannot be used outside the rendering thread");
 
-    m_texture = new QQuickShaderEffectTexture(this);
+    QSGRenderContext *rc = QQuickItemPrivate::get(this)->sceneGraphRenderContext();
+    m_texture = rc->sceneGraphContext()->createLayer(rc);
     connect(QQuickItemPrivate::get(this)->window, SIGNAL(sceneGraphInvalidated()), m_texture, SLOT(invalidated()), Qt::DirectConnection);
     connect(m_texture, SIGNAL(updateRequested()), this, SLOT(update()));
     connect(m_texture, SIGNAL(scheduledUpdateCompleted()), this, SIGNAL(scheduledUpdateCompleted()));
diff --git a/src/quick/items/qquickshadereffectsource_p.h b/src/quick/items/qquickshadereffectsource_p.h
index 4caeaab52c..35899339ce 100644
--- a/src/quick/items/qquickshadereffectsource_p.h
+++ b/src/quick/items/qquickshadereffectsource_p.h
@@ -53,8 +53,6 @@
 #include "qsize.h"
 #include "qrect.h"
 
-#define QSG_DEBUG_FBO_OVERLAY
-
 QT_BEGIN_NAMESPACE
 
 class QSGNode;
@@ -64,95 +62,6 @@ class QSGSimpleRectNode;
 
 class QQuickShaderEffectSourceTextureProvider;
 
-class Q_QUICK_PRIVATE_EXPORT QQuickShaderEffectTexture : public QSGDynamicTexture
-{
-    Q_OBJECT
-public:
-    QQuickShaderEffectTexture(QQuickItem *shaderSource);
-    ~QQuickShaderEffectTexture();
-
-    virtual bool updateTexture();
-
-    // The item's "paint node", not effect node.
-    QSGNode *item() const { return m_item; }
-    void setItem(QSGNode *item);
-
-    void setShaderSourceNode(QSGNode *node) { m_shaderSourceNode = node; }
-
-    QRectF rect() const { return m_rect; }
-    void setRect(const QRectF &rect);
-
-    QSize size() const { return m_size; }
-    void setSize(const QSize &size);
-
-    void setHasMipmaps(bool mipmap);
-
-    void bind();
-
-    bool hasAlphaChannel() const;
-    bool hasMipmaps() const;
-    int textureId() const;
-    QSize textureSize() const { return m_size; }
-
-    GLenum format() const { return m_format; }
-    void setFormat(GLenum format);
-
-    bool live() const { return bool(m_live); }
-    void setLive(bool live);
-
-    bool recursive() const { return bool(m_recursive); }
-    void setRecursive(bool recursive);
-
-    void setDevicePixelRatio(qreal ratio) { m_device_pixel_ratio = ratio; }
-
-    void scheduleUpdate();
-
-    QImage toImage() const;
-
-Q_SIGNALS:
-    void updateRequested();
-    void scheduledUpdateCompleted();
-
-public Q_SLOTS:
-    void markDirtyTexture();
-    void invalidated();
-    void markDirtyTextureLater();
-
-protected:
-    virtual void customEvent(QEvent *);
-
-private:
-    void grab();
-
-    QSGNode *m_item;
-    QSGNode *m_shaderSourceNode;
-    QRectF m_rect;
-    QSize m_size;
-    qreal m_device_pixel_ratio;
-    GLenum m_format;
-
-    QSGRenderer *m_renderer;
-    QOpenGLFramebufferObject *m_fbo;
-    QOpenGLFramebufferObject *m_secondaryFbo;
-    QSharedPointer<QSGDepthStencilBuffer> m_depthStencilBuffer;
-
-    GLuint m_transparentTexture;
-
-#ifdef QSG_DEBUG_FBO_OVERLAY
-    QSGSimpleRectNode *m_debugOverlay;
-#endif
-
-    QSGRenderContext *m_context;
-
-    uint m_mipmap : 1;
-    uint m_live : 1;
-    uint m_recursive : 1;
-    uint m_dirtyTexture : 1;
-    uint m_multisamplingChecked : 1;
-    uint m_multisampling : 1;
-    uint m_grab : 1;
-};
-
 class Q_QUICK_PRIVATE_EXPORT QQuickShaderEffectSource : public QQuickItem, public QQuickItemChangeListener
 {
     Q_OBJECT
@@ -244,7 +153,7 @@ private:
     void ensureTexture();
 
     QQuickShaderEffectSourceTextureProvider *m_provider;
-    QQuickShaderEffectTexture *m_texture;
+    QSGLayer *m_texture;
     WrapMode m_wrapMode;
     QQuickItem *m_sourceItem;
     QRectF m_sourceRect;