Add the graphics api independent scenegraph port

Opt in via environment variables:
QSG_RHI=1 -> enable using QRhi instead of GL
QSG_RHI_BACKEND -> set to vulkan, metal, d3d11, gl to override the default
(the default is d3d11 on Windows, metal on Mac, gl elsewhere)

Or force a given rhi backend via the existing
QQuickWindow::setSceneGraphBackend().

Otherwise the default behavior is the same as before, the rhi code path
is never active by default.

-no-opengl builds are supported in the sense that they work and default
to the software backend. However, the rhi code path cannot currently be
used in such builds, even though QRhi from qtbase is fully functional
with Vulkan, D3D, or Metal even when qtbase was configured with
-no-opengl. This cannot be utilized by Quick atm due to OpenGL usage
being all over the place in the sources corresponding to the default
backend, and those host the rhi code path as well. This will be cleaned up
hopefully in Qt 6, with the removal all direct OpenGL usage.

Other env.vars.:
QSG_RHI_DEBUG_LAYER=1 -> enable D3D debug or Vulkan validation layer
(assuming the system is set up for this)
QSG_RHI_SHADEREFFECT_DEBUG=1 -> print stuff from ShaderEffect
QSG_SAMPLES=1,2,4,... -> MSAA sample count (but QSurfaceFormat works too)
QT_D3D_ADAPTER_INDEX=0,1,... -> D3D adapter index
QT_VK_PHYSICAL_DEVICE_INDEX=0,1,... -> Vulkan physical device index
QSG_RHI_UINT32_INDEX=1 -> always use uint index data (both
merged/unmerged, convert when needed - with some rhi backends this is
implicit)
QSG_RENDER_LOOP -> to override the render loop as usual. The default
with RHI is threaded for Metal, threaded for Vulkan on Windows, basic
for Vulkan on Linux and Android (to be checked later), while the existing
rules apply for OpenGL.

Not supported when running with QRhi:
  - particles
  - compressed atlases (though this is transparent to the apps)
  - QSGRenderNode
  - QQuickRenderControl
  - QQuickFramebufferObject
  - certain QQuickWindow functionality that depends directly on OpenGL
  - anisotropic filtering for textures
  - native text may lack some gamma correction
  - QSGEngine applicability unclear
  - some QML profiler logs may be incorrect or irrelevant

Change-Id: I7822e99ad79e342e4166275da6e9e66498d76521
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 886 insertions, 0 deletions

diff --git a/src/quick/scenegraph/qsgrhishadereffectnode.cpp b/src/quick/scenegraph/qsgrhishadereffectnode.cpp
new file mode 100644
index 0000000000..fe9cecb51b
--- /dev/null
+++ b/src/quick/scenegraph/qsgrhishadereffectnode.cpp
@@ -0,0 +1,886 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQuick module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qsgrhishadereffectnode_p.h"
+#include "qsgdefaultrendercontext_p.h"
+#include "qsgrhisupport_p.h"
+#include <qsgmaterialrhishader.h>
+#include <qsgtextureprovider.h>
+#include <private/qsgplaintexture_p.h>
+#include <QtGui/private/qshaderdescription_p.h>
+#include <QQmlFile>
+#include <QFile>
+#include <QFileSelector>
+
+QT_BEGIN_NAMESPACE
+
+void QSGRhiShaderLinker::reset(const QShader &vs, const QShader &fs)
+{
+    Q_ASSERT(vs.isValid() && fs.isValid());
+    m_vs = vs;
+    m_fs = fs;
+
+    m_error = false;
+
+    m_constantBufferSize = 0;
+    m_constants.clear();
+    m_samplers.clear();
+    m_samplerNameMap.clear();
+}
+
+void QSGRhiShaderLinker::feedConstants(const QSGShaderEffectNode::ShaderData &shader, const QSet<int> *dirtyIndices)
+{
+    Q_ASSERT(shader.shaderInfo.variables.count() == shader.varData.count());
+    if (!dirtyIndices) {
+        m_constantBufferSize = qMax(m_constantBufferSize, shader.shaderInfo.constantDataSize);
+        for (int i = 0; i < shader.shaderInfo.variables.count(); ++i) {
+            const QSGGuiThreadShaderEffectManager::ShaderInfo::Variable &var(shader.shaderInfo.variables.at(i));
+            if (var.type == QSGGuiThreadShaderEffectManager::ShaderInfo::Constant) {
+                const QSGShaderEffectNode::VariableData &vd(shader.varData.at(i));
+                Constant c;
+                c.size = var.size;
+                c.specialType = vd.specialType;
+                if (c.specialType != QSGShaderEffectNode::VariableData::SubRect) {
+                    c.value = vd.value;
+                    if (QSGRhiSupport::instance()->isShaderEffectDebuggingRequested()) {
+                        if (c.specialType == QSGShaderEffectNode::VariableData::None) {
+                            qDebug() << "cbuf prepare" << shader.shaderInfo.name << var.name
+                                     << "offset" << var.offset << "value" << c.value;
+                        } else {
+                            qDebug() << "cbuf prepare" << shader.shaderInfo.name << var.name
+                                     << "offset" << var.offset << "special" << c.specialType;
+                        }
+                    }
+                } else {
+                    Q_ASSERT(var.name.startsWith(QByteArrayLiteral("qt_SubRect_")));
+                    c.value = var.name.mid(11);
+                }
+                m_constants[var.offset] = c;
+            }
+        }
+    } else {
+        for (int idx : *dirtyIndices) {
+            const int offset = shader.shaderInfo.variables.at(idx).offset;
+            const QVariant value = shader.varData.at(idx).value;
+            m_constants[offset].value = value;
+            if (QSGRhiSupport::instance()->isShaderEffectDebuggingRequested()) {
+                qDebug() << "cbuf update" << shader.shaderInfo.name
+                         << "offset" << offset << "value" << value;
+            }
+        }
+    }
+}
+
+void QSGRhiShaderLinker::feedSamplers(const QSGShaderEffectNode::ShaderData &shader, const QSet<int> *dirtyIndices)
+{
+    if (!dirtyIndices) {
+        for (int i = 0; i < shader.shaderInfo.variables.count(); ++i) {
+            const QSGGuiThreadShaderEffectManager::ShaderInfo::Variable &var(shader.shaderInfo.variables.at(i));
+            const QSGShaderEffectNode::VariableData &vd(shader.varData.at(i));
+            if (var.type == QSGGuiThreadShaderEffectManager::ShaderInfo::Sampler) {
+                Q_ASSERT(vd.specialType == QSGShaderEffectNode::VariableData::Source);
+                m_samplers.insert(var.bindPoint, vd.value);
+                m_samplerNameMap.insert(var.name, var.bindPoint);
+            }
+        }
+    } else {
+        for (int idx : *dirtyIndices) {
+            const QSGGuiThreadShaderEffectManager::ShaderInfo::Variable &var(shader.shaderInfo.variables.at(idx));
+            const QSGShaderEffectNode::VariableData &vd(shader.varData.at(idx));
+            m_samplers.insert(var.bindPoint, vd.value);
+            m_samplerNameMap.insert(var.name, var.bindPoint);
+        }
+    }
+}
+
+void QSGRhiShaderLinker::linkTextureSubRects()
+{
+    // feedConstants stores <name> in Constant::value for subrect entries. Now
+    // that both constants and textures are known, replace the name with the
+    // texture binding point.
+    for (Constant &c : m_constants) {
+        if (c.specialType == QSGShaderEffectNode::VariableData::SubRect) {
+            if (c.value.type() == QVariant::ByteArray) {
+                const QByteArray name = c.value.toByteArray();
+                if (!m_samplerNameMap.contains(name))
+                    qWarning("ShaderEffect: qt_SubRect_%s refers to unknown source texture", name.constData());
+                c.value = m_samplerNameMap[name];
+            }
+        }
+    }
+}
+
+void QSGRhiShaderLinker::dump()
+{
+    if (m_error) {
+        qDebug() << "Failed to generate program data";
+        return;
+    }
+    qDebug() << "Combined shader data" << m_vs << m_fs << "cbuffer size" << m_constantBufferSize;
+    qDebug() << " - constants" << m_constants;
+    qDebug() << " - samplers" << m_samplers;
+}
+
+QDebug operator<<(QDebug debug, const QSGRhiShaderLinker::Constant &c)
+{
+    QDebugStateSaver saver(debug);
+    debug.space();
+    debug << "size" << c.size;
+    if (c.specialType != QSGShaderEffectNode::VariableData::None)
+        debug << "special" << c.specialType;
+    else
+        debug << "value" << c.value;
+    return debug;
+}
+
+struct QSGRhiShaderMaterialTypeCache
+{
+    QSGMaterialType *get(const QShader &vs, const QShader &fs);
+    void reset() { qDeleteAll(m_types); m_types.clear(); }
+
+    struct Key {
+        QShader blob[2];
+        Key() { }
+        Key(const QShader &vs, const QShader &fs) { blob[0] = vs; blob[1] = fs; }
+        bool operator==(const Key &other) const {
+            return blob[0] == other.blob[0] && blob[1] == other.blob[1];
+        }
+    };
+    QHash<Key, QSGMaterialType *> m_types;
+};
+
+uint qHash(const QSGRhiShaderMaterialTypeCache::Key &key, uint seed = 0)
+{
+    uint hash = seed;
+    for (int i = 0; i < 2; ++i)
+        hash = hash * 31337 + qHash(key.blob[i]);
+    return hash;
+}
+
+QSGMaterialType *QSGRhiShaderMaterialTypeCache::get(const QShader &vs, const QShader &fs)
+{
+    const Key k(vs, fs);
+    if (m_types.contains(k))
+        return m_types.value(k);
+
+    QSGMaterialType *t = new QSGMaterialType;
+    m_types.insert(k, t);
+    return t;
+}
+
+static QSGRhiShaderMaterialTypeCache shaderMaterialTypeCache;
+
+class QSGRhiShaderEffectMaterialShader : public QSGMaterialRhiShader
+{
+public:
+    QSGRhiShaderEffectMaterialShader(const QSGRhiShaderEffectMaterial *material);
+
+    bool updateUniformData(const RenderState &state, QSGMaterial *newMaterial, QSGMaterial *oldMaterial) override;
+    void updateSampledImage(const RenderState &state, int binding, QSGTexture **texture, QSGMaterial *newMaterial, QSGMaterial *oldMaterial) override;
+    bool updateGraphicsPipelineState(const RenderState &state, GraphicsPipelineState *ps, QSGMaterial *newMaterial, QSGMaterial *oldMaterial) override;
+};
+
+QSGRhiShaderEffectMaterialShader::QSGRhiShaderEffectMaterialShader(const QSGRhiShaderEffectMaterial *material)
+{
+    setFlag(UpdatesGraphicsPipelineState, true);
+    setShader(VertexStage, material->m_vertexShader);
+    setShader(FragmentStage, material->m_fragmentShader);
+}
+
+static inline QColor qsg_premultiply_color(const QColor &c)
+{
+    return QColor::fromRgbF(c.redF() * c.alphaF(), c.greenF() * c.alphaF(), c.blueF() * c.alphaF(), c.alphaF());
+}
+
+bool QSGRhiShaderEffectMaterialShader::updateUniformData(const RenderState &state, QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
+{
+    Q_UNUSED(oldMaterial);
+    QSGRhiShaderEffectMaterial *mat = static_cast<QSGRhiShaderEffectMaterial *>(newMaterial);
+
+    bool changed = false;
+    QByteArray *buf = state.uniformData();
+
+    for (auto it = mat->m_linker.m_constants.constBegin(), itEnd = mat->m_linker.m_constants.constEnd(); it != itEnd; ++it) {
+        const int offset = it.key();
+        char *dst = buf->data() + offset;
+        const QSGRhiShaderLinker::Constant &c(it.value());
+        if (c.specialType == QSGShaderEffectNode::VariableData::Opacity) {
+            if (state.isOpacityDirty()) {
+                const float f = state.opacity();
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, &f, sizeof(f));
+                changed = true;
+            }
+        } else if (c.specialType == QSGShaderEffectNode::VariableData::Matrix) {
+            if (state.isMatrixDirty()) {
+                const int sz = 16 * sizeof(float);
+                Q_ASSERT(sz == c.size);
+                memcpy(dst, state.combinedMatrix().constData(), sz);
+                changed = true;
+            }
+        } else if (c.specialType == QSGShaderEffectNode::VariableData::SubRect) {
+            // vec4
+            QRectF subRect(0, 0, 1, 1);
+            const int binding = c.value.toInt(); // filled in by linkTextureSubRects
+            if (binding < QSGRhiShaderEffectMaterial::MAX_BINDINGS) {
+                if (QSGTextureProvider *tp = mat->m_textureProviders.at(binding)) {
+                    if (QSGTexture *t = tp->texture())
+                        subRect = t->normalizedTextureSubRect();
+                }
+            }
+            const float f[4] = { float(subRect.x()), float(subRect.y()),
+                                 float(subRect.width()), float(subRect.height()) };
+            Q_ASSERT(sizeof(f) == c.size);
+            memcpy(dst, f, sizeof(f));
+        } else if (c.specialType == QSGShaderEffectNode::VariableData::None) {
+            changed = true;
+            switch (int(c.value.type())) {
+            case QMetaType::QColor: {
+                const QColor v = qsg_premultiply_color(qvariant_cast<QColor>(c.value));
+                const float f[4] = { float(v.redF()), float(v.greenF()), float(v.blueF()), float(v.alphaF()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::Float: {
+                const float f = qvariant_cast<float>(c.value);
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, &f, sizeof(f));
+                break;
+            }
+            case QMetaType::Double: {
+                const float f = float(qvariant_cast<double>(c.value));
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, &f, sizeof(f));
+                break;
+            }
+            case QMetaType::Int: {
+                const int i = c.value.toInt();
+                Q_ASSERT(sizeof(i) == c.size);
+                memcpy(dst, &i, sizeof(i));
+                break;
+            }
+            case QMetaType::Bool: {
+                const bool b = c.value.toBool();
+                Q_ASSERT(sizeof(b) == c.size);
+                memcpy(dst, &b, sizeof(b));
+                break;
+            }
+            case QMetaType::QTransform: { // mat3
+                const QTransform v = qvariant_cast<QTransform>(c.value);
+                const float m[3][3] = {
+                    { float(v.m11()), float(v.m12()), float(v.m13()) },
+                    { float(v.m21()), float(v.m22()), float(v.m23()) },
+                    { float(v.m31()), float(v.m32()), float(v.m33()) }
+                };
+                Q_ASSERT(sizeof(m) == c.size);
+                memcpy(dst, m[0], sizeof(m));
+                break;
+            }
+            case QMetaType::QSize:
+            case QMetaType::QSizeF: { // vec2
+                const QSizeF v = c.value.toSizeF();
+                const float f[2] = { float(v.width()), float(v.height()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QPoint:
+            case QMetaType::QPointF: { // vec2
+                const QPointF v = c.value.toPointF();
+                const float f[2] = { float(v.x()), float(v.y()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QRect:
+            case QMetaType::QRectF: { // vec4
+                const QRectF v = c.value.toRectF();
+                const float f[4] = { float(v.x()), float(v.y()), float(v.width()), float(v.height()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QVector2D: { // vec2
+                const QVector2D v = qvariant_cast<QVector2D>(c.value);
+                const float f[2] = { float(v.x()), float(v.y()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QVector3D: { // vec3
+                const QVector3D v = qvariant_cast<QVector3D>(c.value);
+                const float f[3] = { float(v.x()), float(v.y()), float(v.z()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QVector4D: { // vec4
+                const QVector4D v = qvariant_cast<QVector4D>(c.value);
+                const float f[4] = { float(v.x()), float(v.y()), float(v.z()), float(v.w()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QQuaternion: { // vec4
+                const QQuaternion v = qvariant_cast<QQuaternion>(c.value);
+                const float f[4] = { float(v.x()), float(v.y()), float(v.z()), float(v.scalar()) };
+                Q_ASSERT(sizeof(f) == c.size);
+                memcpy(dst, f, sizeof(f));
+                break;
+            }
+            case QMetaType::QMatrix4x4: { // mat4
+                const QMatrix4x4 v = qvariant_cast<QMatrix4x4>(c.value);
+                const int sz = 16 * sizeof(float);
+                Q_ASSERT(sz == c.size);
+                memcpy(dst, v.constData(), sz);
+                break;
+            }
+            default:
+                break;
+            }
+        }
+    }
+
+    return changed;
+}
+
+void QSGRhiShaderEffectMaterialShader::updateSampledImage(const RenderState &state, int binding, QSGTexture **texture,
+                                                          QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
+{
+    Q_UNUSED(oldMaterial);
+    QSGRhiShaderEffectMaterial *mat = static_cast<QSGRhiShaderEffectMaterial *>(newMaterial);
+
+    if (binding >= QSGRhiShaderEffectMaterial::MAX_BINDINGS)
+        return;
+
+    QSGTextureProvider *tp = mat->m_textureProviders.at(binding);
+    if (tp) {
+        if (QSGTexture *t = tp->texture()) {
+            t->updateRhiTexture(state.rhi(), state.resourceUpdateBatch());
+            if (t->isAtlasTexture() && !mat->m_geometryUsesTextureSubRect) {
+                // Why the hassle with the batch: while removedFromAtlas() is
+                // able to operate with its own resource update batch (which is
+                // then committed immediately), that approach is wrong when the
+                // atlas enqueued (in the updateRhiTexture() above) not yet
+                // committed operations to state.resourceUpdateBatch()... The
+                // only safe way then is to use the same batch the atlas'
+                // updateRhiTexture() used.
+                t->setWorkResourceUpdateBatch(state.resourceUpdateBatch());
+                QSGTexture *newTexture = t->removedFromAtlas();
+                t->setWorkResourceUpdateBatch(nullptr);
+                if (newTexture)
+                    t = newTexture;
+            }
+            *texture = t;
+            return;
+        }
+    }
+
+    if (!mat->m_dummyTexture) {
+        mat->m_dummyTexture = new QSGPlainTexture;
+        mat->m_dummyTexture->setFiltering(QSGTexture::Nearest);
+        mat->m_dummyTexture->setHorizontalWrapMode(QSGTexture::Repeat);
+        mat->m_dummyTexture->setVerticalWrapMode(QSGTexture::Repeat);
+        QImage img(128, 128, QImage::Format_ARGB32_Premultiplied);
+        img.fill(0);
+        mat->m_dummyTexture->setImage(img);
+        mat->m_dummyTexture->updateRhiTexture(state.rhi(), state.resourceUpdateBatch());
+    }
+    *texture = mat->m_dummyTexture;
+}
+
+bool QSGRhiShaderEffectMaterialShader::updateGraphicsPipelineState(const RenderState &state, GraphicsPipelineState *ps,
+                                                                   QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
+{
+    Q_UNUSED(state);
+    Q_UNUSED(oldMaterial);
+    QSGRhiShaderEffectMaterial *mat = static_cast<QSGRhiShaderEffectMaterial *>(newMaterial);
+
+    switch (mat->m_cullMode) {
+    case QSGShaderEffectNode::FrontFaceCulling:
+        ps->cullMode = GraphicsPipelineState::CullFront;
+        return true;
+    case QSGShaderEffectNode::BackFaceCulling:
+        ps->cullMode = GraphicsPipelineState::CullBack;
+        return true;
+    default:
+        return false;
+    }
+}
+
+QSGRhiShaderEffectMaterial::QSGRhiShaderEffectMaterial(QSGRhiShaderEffectNode *node)
+    : m_node(node)
+{
+    setFlag(SupportsRhiShader | Blending | RequiresFullMatrix, true); // may be changed in syncMaterial()
+}
+
+QSGRhiShaderEffectMaterial::~QSGRhiShaderEffectMaterial()
+{
+    delete m_dummyTexture;
+}
+
+static bool hasAtlasTexture(const QVector<QSGTextureProvider *> &textureProviders)
+{
+    for (QSGTextureProvider *tp : textureProviders) {
+        if (tp && tp->texture() && tp->texture()->isAtlasTexture())
+            return true;
+    }
+    return false;
+}
+
+int QSGRhiShaderEffectMaterial::compare(const QSGMaterial *other) const
+{
+    Q_ASSERT(other && type() == other->type());
+    const QSGRhiShaderEffectMaterial *o = static_cast<const QSGRhiShaderEffectMaterial *>(other);
+
+    if (int diff = m_cullMode - o->m_cullMode)
+        return diff;
+
+    if (int diff = m_textureProviders.count() - o->m_textureProviders.count())
+        return diff;
+
+    if (m_linker.m_constants != o->m_linker.m_constants)
+        return 1;
+
+    if (hasAtlasTexture(m_textureProviders) && !m_geometryUsesTextureSubRect)
+        return -1;
+
+    if (hasAtlasTexture(o->m_textureProviders) && !o->m_geometryUsesTextureSubRect)
+        return 1;
+
+    for (int binding = 0, count = m_textureProviders.count(); binding != count; ++binding) {
+        QSGTextureProvider *tp1 = m_textureProviders.at(binding);
+        QSGTextureProvider *tp2 = o->m_textureProviders.at(binding);
+        if (tp1 && tp2) {
+            QSGTexture *t1 = tp1->texture();
+            QSGTexture *t2 = tp2->texture();
+            if (t1 && t2) {
+                if (int diff = t1->comparisonKey() - t2->comparisonKey())
+                    return diff;
+            } else {
+                if (!t1 && t2)
+                    return -1;
+                if (t1 && !t2)
+                    return 1;
+            }
+        } else {
+            if (!tp1 && tp2)
+                return -1;
+            if (tp1 && !tp2)
+                return 1;
+        }
+    }
+
+    return 0;
+}
+
+QSGMaterialType *QSGRhiShaderEffectMaterial::type() const
+{
+    return m_materialType;
+}
+
+QSGMaterialShader *QSGRhiShaderEffectMaterial::createShader() const
+{
+    Q_ASSERT(flags().testFlag(RhiShaderWanted));
+    return new QSGRhiShaderEffectMaterialShader(this);
+}
+
+void QSGRhiShaderEffectMaterial::updateTextureProviders(bool layoutChange)
+{
+    if (layoutChange) {
+        for (QSGTextureProvider *tp : m_textureProviders) {
+            if (tp) {
+                QObject::disconnect(tp, SIGNAL(textureChanged()), m_node,
+                                    SLOT(handleTextureChange()));
+                QObject::disconnect(tp, SIGNAL(destroyed(QObject*)), m_node,
+                                    SLOT(handleTextureProviderDestroyed(QObject*)));
+            }
+        }
+        m_textureProviders.fill(nullptr, MAX_BINDINGS);
+    }
+
+    for (auto it = m_linker.m_samplers.constBegin(), itEnd = m_linker.m_samplers.constEnd(); it != itEnd; ++it) {
+        const int binding = it.key();
+        QQuickItem *source = qobject_cast<QQuickItem *>(qvariant_cast<QObject *>(it.value()));
+        QSGTextureProvider *newProvider = source && source->isTextureProvider() ? source->textureProvider() : nullptr;
+        if (binding >= MAX_BINDINGS) {
+            qWarning("Sampler at binding %d exceeds the available ShaderEffect binding slots; ignored",
+                     binding);
+            continue;
+        }
+        QSGTextureProvider *&activeProvider(m_textureProviders[binding]);
+        if (newProvider != activeProvider) {
+            if (activeProvider) {
+                QObject::disconnect(activeProvider, SIGNAL(textureChanged()), m_node,
+                                    SLOT(handleTextureChange()));
+                QObject::disconnect(activeProvider, SIGNAL(destroyed(QObject*)), m_node,
+                                    SLOT(handleTextureProviderDestroyed(QObject*)));
+            }
+            if (newProvider) {
+                Q_ASSERT_X(newProvider->thread() == QThread::currentThread(),
+                           "QSGRhiShaderEffectMaterial::updateTextureProviders",
+                           "Texture provider must belong to the rendering thread");
+                QObject::connect(newProvider, SIGNAL(textureChanged()), m_node, SLOT(handleTextureChange()));
+                QObject::connect(newProvider, SIGNAL(destroyed(QObject*)), m_node,
+                                 SLOT(handleTextureProviderDestroyed(QObject*)));
+            } else {
+                const char *typeName = source ? source->metaObject()->className() : it.value().typeName();
+                qWarning("ShaderEffect: Texture t%d is not assigned a valid texture provider (%s).",
+                         binding, typeName);
+            }
+            activeProvider = newProvider;
+        }
+    }
+}
+
+QSGRhiShaderEffectNode::QSGRhiShaderEffectNode(QSGDefaultRenderContext *rc, QSGRhiGuiThreadShaderEffectManager *mgr)
+    : QSGShaderEffectNode(mgr),
+      m_rc(rc),
+      m_mgr(mgr),
+      m_material(this)
+{
+    setFlag(UsePreprocess, true);
+    setMaterial(&m_material);
+}
+
+QRectF QSGRhiShaderEffectNode::updateNormalizedTextureSubRect(bool supportsAtlasTextures)
+{
+    QRectF srcRect(0, 0, 1, 1);
+    bool geometryUsesTextureSubRect = false;
+    if (supportsAtlasTextures) {
+        QSGTextureProvider *tp = nullptr;
+        for (int binding = 0, count = m_material.m_textureProviders.count(); binding != count; ++binding) {
+            if (QSGTextureProvider *candidate = m_material.m_textureProviders.at(binding)) {
+                if (!tp) {
+                    tp = candidate;
+                } else { // there can only be one...
+                    tp = nullptr;
+                    break;
+                }
+            }
+        }
+        if (tp && tp->texture()) {
+            srcRect = tp->texture()->normalizedTextureSubRect();
+            geometryUsesTextureSubRect = true;
+        }
+    }
+
+    if (m_material.m_geometryUsesTextureSubRect != geometryUsesTextureSubRect) {
+        m_material.m_geometryUsesTextureSubRect = geometryUsesTextureSubRect;
+        markDirty(QSGNode::DirtyMaterial);
+    }
+
+    return srcRect;
+}
+
+static QShader loadShader(const QString &filename)
+{
+    QFile f(filename);
+    if (!f.open(QIODevice::ReadOnly)) {
+        qWarning() << "Failed to find shader" << filename;
+        return QShader();
+    }
+    return QShader::fromSerialized(f.readAll());
+}
+
+void QSGRhiShaderEffectNode::syncMaterial(SyncData *syncData)
+{
+    static QShader defaultVertexShader;
+    static QShader defaultFragmentShader;
+
+    if (bool(m_material.flags() & QSGMaterial::Blending) != syncData->blending) {
+        m_material.setFlag(QSGMaterial::Blending, syncData->blending);
+        markDirty(QSGNode::DirtyMaterial);
+    }
+
+    if (m_material.m_cullMode != syncData->cullMode) {
+        m_material.m_cullMode = syncData->cullMode;
+        markDirty(QSGNode::DirtyMaterial);
+    }
+
+    if (syncData->dirty & QSGShaderEffectNode::DirtyShaders) {
+        m_material.m_hasCustomVertexShader = syncData->vertex.shader->hasShaderCode;
+        if (m_material.m_hasCustomVertexShader) {
+            m_material.m_vertexShader = syncData->vertex.shader->shaderInfo.rhiShader;
+        } else {
+            if (!defaultVertexShader.isValid())
+                defaultVertexShader = loadShader(QStringLiteral(":/qt-project.org/scenegraph/shaders_ng/shadereffect.vert.qsb"));
+            m_material.m_vertexShader = defaultVertexShader;
+        }
+
+        m_material.m_hasCustomFragmentShader = syncData->fragment.shader->hasShaderCode;
+        if (m_material.m_hasCustomFragmentShader) {
+            m_material.m_fragmentShader = syncData->fragment.shader->shaderInfo.rhiShader;
+        } else {
+            if (!defaultFragmentShader.isValid())
+                defaultFragmentShader = loadShader(QStringLiteral(":/qt-project.org/scenegraph/shaders_ng/shadereffect.frag.qsb"));
+            m_material.m_fragmentShader = defaultFragmentShader;
+        }
+
+        m_material.m_materialType = shaderMaterialTypeCache.get(m_material.m_vertexShader, m_material.m_fragmentShader);
+        m_material.m_linker.reset(m_material.m_vertexShader, m_material.m_fragmentShader);
+
+        if (m_material.m_hasCustomVertexShader) {
+            m_material.m_linker.feedConstants(*syncData->vertex.shader);
+            m_material.m_linker.feedSamplers(*syncData->vertex.shader);
+        } else {
+            QSGShaderEffectNode::ShaderData defaultSD;
+            defaultSD.shaderInfo.name = QLatin1String("Default ShaderEffect vertex shader");
+            defaultSD.shaderInfo.rhiShader = m_material.m_vertexShader;
+            defaultSD.shaderInfo.type = QSGGuiThreadShaderEffectManager::ShaderInfo::TypeVertex;
+
+            // { mat4 qt_Matrix; float qt_Opacity; } where only the matrix is used
+            QSGGuiThreadShaderEffectManager::ShaderInfo::Variable v;
+            v.name = QByteArrayLiteral("qt_Matrix");
+            v.offset = 0;
+            v.size = 16 * sizeof(float);
+            defaultSD.shaderInfo.variables.append(v);
+            QSGShaderEffectNode::VariableData vd;
+            vd.specialType = QSGShaderEffectNode::VariableData::Matrix;
+            defaultSD.varData.append(vd);
+            defaultSD.shaderInfo.constantDataSize = (16 + 1) * sizeof(float);
+            m_material.m_linker.feedConstants(defaultSD);
+        }
+
+        if (m_material.m_hasCustomFragmentShader) {
+            m_material.m_linker.feedConstants(*syncData->fragment.shader);
+            m_material.m_linker.feedSamplers(*syncData->fragment.shader);
+        } else {
+            QSGShaderEffectNode::ShaderData defaultSD;
+            defaultSD.shaderInfo.name = QLatin1String("Default ShaderEffect fragment shader");
+            defaultSD.shaderInfo.rhiShader = m_material.m_fragmentShader;
+            defaultSD.shaderInfo.type = QSGGuiThreadShaderEffectManager::ShaderInfo::TypeFragment;
+
+            // { mat4 qt_Matrix; float qt_Opacity; } where only the opacity is used
+            QSGGuiThreadShaderEffectManager::ShaderInfo::Variable v;
+            v.name = QByteArrayLiteral("qt_Opacity");
+            v.offset = 16 * sizeof(float);
+            v.size = sizeof(float);
+            defaultSD.shaderInfo.variables.append(v);
+            QSGShaderEffectNode::VariableData vd;
+            vd.specialType = QSGShaderEffectNode::VariableData::Opacity;
+            defaultSD.varData.append(vd);
+
+            v.name = QByteArrayLiteral("source");
+            v.bindPoint = 1;
+            v.type = QSGGuiThreadShaderEffectManager::ShaderInfo::Sampler;
+            defaultSD.shaderInfo.variables.append(v);
+            for (const QSGShaderEffectNode::VariableData &extVarData : qAsConst(syncData->fragment.shader->varData)) {
+                if (extVarData.specialType == QSGShaderEffectNode::VariableData::Source) {
+                    vd.value = extVarData.value;
+                    break;
+                }
+            }
+            vd.specialType = QSGShaderEffectNode::VariableData::Source;
+            defaultSD.varData.append(vd);
+
+            defaultSD.shaderInfo.constantDataSize = (16 + 1) * sizeof(float);
+
+            m_material.m_linker.feedConstants(defaultSD);
+            m_material.m_linker.feedSamplers(defaultSD);
+        }
+
+        m_material.m_linker.linkTextureSubRects();
+        m_material.updateTextureProviders(true);
+        markDirty(QSGNode::DirtyMaterial);
+
+    } else  {
+
+        if (syncData->dirty & QSGShaderEffectNode::DirtyShaderConstant) {
+            if (!syncData->vertex.dirtyConstants->isEmpty())
+                m_material.m_linker.feedConstants(*syncData->vertex.shader, syncData->vertex.dirtyConstants);
+            if (!syncData->fragment.dirtyConstants->isEmpty())
+                m_material.m_linker.feedConstants(*syncData->fragment.shader, syncData->fragment.dirtyConstants);
+            markDirty(QSGNode::DirtyMaterial);
+        }
+
+        if (syncData->dirty & QSGShaderEffectNode::DirtyShaderTexture) {
+            if (!syncData->vertex.dirtyTextures->isEmpty())
+                m_material.m_linker.feedSamplers(*syncData->vertex.shader, syncData->vertex.dirtyTextures);
+            if (!syncData->fragment.dirtyTextures->isEmpty())
+                m_material.m_linker.feedSamplers(*syncData->fragment.shader, syncData->fragment.dirtyTextures);
+            m_material.m_linker.linkTextureSubRects();
+            m_material.updateTextureProviders(false);
+            markDirty(QSGNode::DirtyMaterial);
+        }
+    }
+
+    if (bool(m_material.flags() & QSGMaterial::RequiresFullMatrix) != m_material.m_hasCustomVertexShader) {
+        m_material.setFlag(QSGMaterial::RequiresFullMatrix, m_material.m_hasCustomVertexShader);
+        markDirty(QSGNode::DirtyMaterial);
+    }
+}
+
+void QSGRhiShaderEffectNode::handleTextureChange()
+{
+    markDirty(QSGNode::DirtyMaterial);
+    emit m_mgr->textureChanged();
+}
+
+void QSGRhiShaderEffectNode::handleTextureProviderDestroyed(QObject *object)
+{
+    for (QSGTextureProvider *&tp : m_material.m_textureProviders) {
+        if (tp == object)
+            tp = nullptr;
+    }
+}
+
+void QSGRhiShaderEffectNode::preprocess()
+{
+    for (QSGTextureProvider *tp : m_material.m_textureProviders) {
+        if (tp) {
+            if (QSGDynamicTexture *texture = qobject_cast<QSGDynamicTexture *>(tp->texture()))
+                texture->updateTexture();
+        }
+    }
+}
+
+void QSGRhiShaderEffectNode::cleanupMaterialTypeCache()
+{
+    shaderMaterialTypeCache.reset();
+}
+
+bool QSGRhiGuiThreadShaderEffectManager::hasSeparateSamplerAndTextureObjects() const
+{
+    return false; // because SPIR-V and QRhi make it look so, regardless of the underlying API
+}
+
+QString QSGRhiGuiThreadShaderEffectManager::log() const
+{
+    return QString();
+}
+
+QSGGuiThreadShaderEffectManager::Status QSGRhiGuiThreadShaderEffectManager::status() const
+{
+    return m_status;
+}
+
+void QSGRhiGuiThreadShaderEffectManager::prepareShaderCode(ShaderInfo::Type typeHint, const QByteArray &src, ShaderInfo *result)
+{
+    QUrl srcUrl(QString::fromUtf8(src));
+    if (!srcUrl.scheme().compare(QLatin1String("qrc"), Qt::CaseInsensitive) || srcUrl.isLocalFile()) {
+        if (!m_fileSelector) {
+            m_fileSelector = new QFileSelector(this);
+            m_fileSelector->setExtraSelectors(QStringList() << QStringLiteral("qsb"));
+        }
+        const QString fn = m_fileSelector->select(QQmlFile::urlToLocalFileOrQrc(srcUrl));
+        QFile f(fn);
+        if (!f.open(QIODevice::ReadOnly)) {
+            qWarning("ShaderEffect: Failed to read %s", qPrintable(fn));
+            m_status = Error;
+            emit shaderCodePrepared(false, typeHint, src, result);
+            emit logAndStatusChanged();
+            return;
+        }
+        const QShader s = QShader::fromSerialized(f.readAll());
+        f.close();
+        if (!s.isValid()) {
+            qWarning("ShaderEffect: Failed to deserialize QShader from %s", qPrintable(fn));
+            m_status = Error;
+            emit shaderCodePrepared(false, typeHint, src, result);
+            emit logAndStatusChanged();
+            return;
+        }
+        result->name = fn;
+        result->rhiShader = s;
+        const bool ok = reflect(result);
+        m_status = ok ? Compiled : Error;
+        emit shaderCodePrepared(ok, typeHint, src, result);
+        emit logAndStatusChanged();
+    } else {
+        qWarning("rhi shader effect only supports files (qrc or local) at the moment");
+        emit shaderCodePrepared(false, typeHint, src, result);
+    }
+}
+
+bool QSGRhiGuiThreadShaderEffectManager::reflect(ShaderInfo *result)
+{
+    switch (result->rhiShader.stage()) {
+    case QShader::VertexStage:
+        result->type = ShaderInfo::TypeVertex;
+        break;
+    case QShader::FragmentStage:
+        result->type = ShaderInfo::TypeFragment;
+        break;
+    default:
+        result->type = ShaderInfo::TypeOther;
+        qWarning("Unsupported shader stage (%d)", result->rhiShader.stage());
+        return false;
+    }
+
+    const QShaderDescription desc = result->rhiShader.description();
+    result->constantDataSize = 0;
+
+    int ubufBinding = -1;
+    const QVector<QShaderDescription::UniformBlock> ubufs = desc.uniformBlocks();
+    const int ubufCount = ubufs.count();
+    for (int i = 0; i < ubufCount; ++i) {
+        const QShaderDescription::UniformBlock &ubuf(ubufs[i]);
+        if (ubufBinding == -1 && ubuf.binding >= 0) {
+            ubufBinding = ubuf.binding;
+            result->constantDataSize = ubuf.size;
+            for (const QShaderDescription::BlockVariable &member : ubuf.members) {
+                ShaderInfo::Variable v;
+                v.type = ShaderInfo::Constant;
+                v.name = member.name.toUtf8();
+                v.offset = member.offset;
+                v.size = member.size;
+                result->variables.append(v);
+            }
+        } else {
+            qWarning("Uniform block %s (binding %d) ignored", qPrintable(ubuf.blockName), ubuf.binding);
+        }
+    }
+
+    const QVector<QShaderDescription::InOutVariable> combinedImageSamplers = desc.combinedImageSamplers();
+    const int samplerCount = combinedImageSamplers.count();
+    for (int i = 0; i < samplerCount; ++i) {
+        const QShaderDescription::InOutVariable &combinedImageSampler(combinedImageSamplers[i]);
+        ShaderInfo::Variable v;
+        v.type = ShaderInfo::Sampler;
+        v.name = combinedImageSampler.name.toUtf8();
+        v.bindPoint = combinedImageSampler.binding;
+        result->variables.append(v);
+    }
+
+    return true;
+}
+
+QT_END_NAMESPACE