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// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include "rhirenderingextensions.h"
#include "cube.h"
#include <QGuiApplication>
#include <QFile>
#include <ssg/qquick3dextensionhelpers.h>
#include <ssg/qssgrendercontextcore.h>
#include <ssg/qssgrenderextensions.h>
#include <ssg/qssgrenderhelpers.h>
// The extension exposed to QML is the consumer, backed by an extension node
// with Main mode that renders a textured cube within the main render pass. It
// automatically creates a child extension, acting as the producer. This
// backend node for this has the Standalone mode, as it creates and renders
// into a QRhiTexture (doing its own render pass with a custom render target).
//
// The order is like this because extension backend nodes are invoked
// (prepareData, prepareRender, render) in a bottom-up order based on the
// frontend object relationships, i.e. the backend node of a child gets its
// functions called before the backend node of its parent. For siblings the
// order is undefined.
class ProducerRenderer : public QSSGRenderExtension
{
public:
ProducerRenderer();
~ProducerRenderer();
bool prepareData(QSSGFrameData &data) override;
void prepareRender(QSSGFrameData &data) override;
void render(QSSGFrameData &data) override;
void resetForFrame() override;
RenderMode mode() const override { return RenderMode::Standalone; }
RenderStage stage() const override { return RenderStage::PostColor; }
std::unique_ptr<QRhiTexture> texture;
std::unique_ptr<QRhiTextureRenderTarget> rt;
std::unique_ptr<QRhiRenderPassDescriptor> rpDesc;
std::unique_ptr<QRhiBuffer> vbuf;
std::unique_ptr<QRhiBuffer> ubuf;
std::unique_ptr<QRhiShaderResourceBindings> srb;
std::unique_ptr<QRhiGraphicsPipeline> ps;
float rotation = 0.0f;
};
ProducerRenderer::ProducerRenderer()
{
qDebug() << "ProducerRenderer" << this << "ctor; current thread:" << QThread::currentThread() << "main thread:" << qGuiApp->thread();
}
ProducerRenderer::~ProducerRenderer()
{
qDebug() << "ProducerRenderer" << this << "dtor; current thread:" << QThread::currentThread() << "main thread:" << qGuiApp->thread();
}
bool ProducerRenderer::prepareData(QSSGFrameData &)
{
return true;
}
static QShader getShader(const QString &name)
{
QFile f(name);
return f.open(QIODevice::ReadOnly) ? QShader::fromSerialized(f.readAll()) : QShader();
}
static float triangle[] = {
0.0f, 0.5f, 1.0f, 0.0f, 0.0f,
-0.5f, -0.5f, 0.0f, 1.0f, 0.0f,
0.5f, -0.5f, 0.0f, 0.0f, 1.0f,
};
void ProducerRenderer::prepareRender(QSSGFrameData &data)
{
const std::unique_ptr<QSSGRhiContext> &rhiCtx = data.contextInterface()->rhiContext();
if (!rhiCtx)
return;
QRhi *rhi = rhiCtx->rhi();
if (!texture) {
texture.reset(rhi->newTexture(QRhiTexture::RGBA8, QSize(512, 512), 1, QRhiTexture::RenderTarget));
texture->create();
rt.reset(rhi->newTextureRenderTarget({ texture.get() }));
rpDesc.reset(rt->newCompatibleRenderPassDescriptor());
rt->setRenderPassDescriptor(rpDesc.get());
rt->create();
}
if (!ps) {
vbuf.reset(rhi->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(triangle)));
vbuf->create();
ubuf.reset(rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 64));
ubuf->create();
srb.reset(rhi->newShaderResourceBindings());
srb->setBindings({
QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage, ubuf.get()),
});
srb->create();
ps.reset(rhi->newGraphicsPipeline());
ps->setShaderStages({
{ QRhiShaderStage::Vertex, getShader(QLatin1String(":/shaders/color.vert.qsb")) },
{ QRhiShaderStage::Fragment, getShader(QLatin1String(":/shaders/color.frag.qsb")) }
});
QRhiVertexInputLayout inputLayout;
inputLayout.setBindings({
{ 5 * sizeof(float) }
});
inputLayout.setAttributes({
{ 0, 0, QRhiVertexInputAttribute::Float2, 0 },
{ 0, 1, QRhiVertexInputAttribute::Float3, 2 * sizeof(float) }
});
ps->setVertexInputLayout(inputLayout);
ps->setShaderResourceBindings(srb.get());
ps->setRenderPassDescriptor(rpDesc.get());
ps->create();
QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
QRhiResourceUpdateBatch *resourceUpdates = rhi->nextResourceUpdateBatch();
resourceUpdates->uploadStaticBuffer(vbuf.get(), triangle);
cb->resourceUpdate(resourceUpdates);
}
}
void ProducerRenderer::render(QSSGFrameData &data)
{
const std::unique_ptr<QSSGRhiContext> &rhiCtx = data.contextInterface()->rhiContext();
if (!rhiCtx)
return;
QRhi *rhi = rhiCtx->rhi();
QRhiResourceUpdateBatch *resourceUpdates = rhi->nextResourceUpdateBatch();
const QSize outputSize = rt->pixelSize();
QMatrix4x4 viewProjection = rhi->clipSpaceCorrMatrix();
viewProjection.perspective(45.0f, outputSize.width() / (float) outputSize.height(), 0.01f, 1000.0f);
viewProjection.translate(0, 0, -4);
QMatrix4x4 modelViewProjection = viewProjection;
modelViewProjection.rotate(rotation, 0, 1, 0);
resourceUpdates->updateDynamicBuffer(ubuf.get(), 0, 64, modelViewProjection.constData());
QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
const QColor clearColor = QColor::fromRgbF(0.4f, 0.7f, 0.0f, 1.0f);
cb->beginPass(rt.get(), clearColor, { 1.0f, 0}, resourceUpdates);
cb->setGraphicsPipeline(ps.get());
cb->setViewport(QRhiViewport(0, 0, outputSize.width(), outputSize.height()));
cb->setShaderResources();
const QRhiCommandBuffer::VertexInput vbufBinding(vbuf.get(), 0);
cb->setVertexInput(0, 1, &vbufBinding);
cb->draw(3);
cb->endPass();
}
void ProducerRenderer::resetForFrame()
{
}
class ProducerExtension : public QQuick3DRenderExtension
{
public:
ProducerExtension(QQuick3DRenderExtension *parent = nullptr)
: QQuick3DRenderExtension(parent)
{
}
QSSGRenderGraphObject *updateSpatialNode(QSSGRenderGraphObject *node) override;
ProducerRenderer *renderer = nullptr;
float rotation = 0.0f;
};
QSSGRenderGraphObject *ProducerExtension::updateSpatialNode(QSSGRenderGraphObject *node)
{
if (!renderer)
renderer = new ProducerRenderer;
if (node != renderer) {
delete node;
node = renderer;
}
renderer->rotation = rotation;
return node;
}
class ConsumerRenderer : public QSSGRenderExtension
{
public:
ConsumerRenderer(ProducerExtension *producer);
~ConsumerRenderer();
bool prepareData(QSSGFrameData &data) override;
void prepareRender(QSSGFrameData &data) override;
void render(QSSGFrameData &data) override;
void resetForFrame() override;
RenderMode mode() const override { return RenderMode::Main; }
RenderStage stage() const override { return RenderStage::PostColor; }
ProducerExtension *producer;
bool canRender = false;
QMatrix4x4 viewProjection;
QRhiViewport mainViewport;
std::unique_ptr<QRhiBuffer> vbuf;
std::unique_ptr<QRhiBuffer> ubuf;
std::unique_ptr<QRhiSampler> sampler;
std::unique_ptr<QRhiShaderResourceBindings> srb;
std::unique_ptr<QRhiGraphicsPipeline> ps;
QVector<quint32> rpFormat;
QMatrix4x4 modelMatrix;
void updateModelMatrix(const QVector3D &pos)
{
modelMatrix.setToIdentity();
modelMatrix.translate(pos);
modelMatrix.scale(10, 10, 10);
}
};
ConsumerRenderer::ConsumerRenderer(ProducerExtension *producer)
: producer(producer)
{
qDebug() << "ConsumerRenderer" << this << "ctor; current thread:" << QThread::currentThread() << "main thread:" << qGuiApp->thread();
}
ConsumerRenderer::~ConsumerRenderer()
{
qDebug() << "ConsumerRenderer" << this << "dtor; current thread:" << QThread::currentThread() << "main thread:" << qGuiApp->thread();
}
bool ConsumerRenderer::prepareData(QSSGFrameData &data)
{
auto camera = data.activeCamera();
if (camera == QSSGCameraId::Invalid) {
canRender = false;
return false;
}
viewProjection = QSSGCameraHelpers::getViewProjectionMatrix(camera);
canRender = true;
return true;
}
void ConsumerRenderer::prepareRender(QSSGFrameData &data)
{
if (!canRender)
return;
// Due to lifetime guarantees (that the backend node of the child frontend
// object is destroyed before the backend node of the parent frontend
// object), accessing producer->m_renderer should always be safe in
// ConsumerRenderer.
QRhiTexture *texture = producer->renderer->texture.get();
if (!texture)
qFatal("No texture from producer");
const std::unique_ptr<QSSGRhiContext> &rhiCtx = data.contextInterface()->rhiContext();
if (!rhiCtx)
return;
QRhi *rhi = rhiCtx->rhi();
QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
QRhiResourceUpdateBatch *resourceUpdates = rhi->nextResourceUpdateBatch();
// The SceneEnvironment changes the MSAA setting dynamically. To follow
// this, we need this extra check so that we can recreate the graphics
// pipeline with the correct sample count upon a change.
if (ps && ps->sampleCount() != rhiCtx->mainPassSampleCount())
ps.reset();
// This is not strictly required for this application. However, if there is
// a chance that the View3D moves to become a (texture-backed) layer, part
// of a ShaderEffect, or gets moved to a new window, robust implementations
// should prepare for that like this, since some render target parameters
// may be different then, which may imply that the graphics pipeline needs
// to be recreated.
QVector<quint32> currentRpFormat = rhiCtx->mainRenderPassDescriptor()->serializedFormat();
if (ps && rpFormat != currentRpFormat)
ps.reset();
if (!ps) {
vbuf.reset(rhi->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(cube)));
vbuf->create();
resourceUpdates->uploadStaticBuffer(vbuf.get(), cube);
ubuf.reset(rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 64 + 16));
ubuf->create();
sampler.reset(rhi->newSampler(QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge));
sampler->create();
srb.reset(rhi->newShaderResourceBindings());
srb->setBindings({
QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage, ubuf.get()),
QRhiShaderResourceBinding::sampledTexture(1, QRhiShaderResourceBinding::FragmentStage, texture, sampler.get())
});
srb->create();
ps.reset(rhi->newGraphicsPipeline());
// depth testing is important since we test against the objects already rendered by the View3D. (the mode is Overlay)
ps->setDepthTest(true);
ps->setDepthWrite(true);
ps->setCullMode(QRhiGraphicsPipeline::Back);
ps->setShaderStages({
{ QRhiShaderStage::Vertex, getShader(QLatin1String(":/shaders/texture.vert.qsb")) },
{ QRhiShaderStage::Fragment, getShader(QLatin1String(":/shaders/texture.frag.qsb")) }
});
QRhiVertexInputLayout inputLayout;
// The cube is provided as non-interleaved sets of positions, UVs, normals.
// Normals are not interesting here, only need the positions and UVs.
inputLayout.setBindings({
{ 3 * sizeof(float) },
{ 2 * sizeof(float) }
});
inputLayout.setAttributes({
{ 0, 0, QRhiVertexInputAttribute::Float3, 0 },
{ 1, 1, QRhiVertexInputAttribute::Float2, 0 }
});
ps->setVertexInputLayout(inputLayout);
ps->setShaderResourceBindings(srb.get());
// Must play nice with the View3D's render target.
ps->setRenderPassDescriptor(rhiCtx->mainRenderPassDescriptor());
rpFormat = currentRpFormat;
ps->setSampleCount(rhiCtx->mainPassSampleCount());
ps->create();
}
// clipSpaceCorrMatrix has to be applied manually
QMatrix4x4 mvp = rhi->clipSpaceCorrMatrix() * viewProjection * modelMatrix;
resourceUpdates->updateDynamicBuffer(ubuf.get(), 0, 64, mvp.constData());
QVector4D color(0, 0.5f, 0, 1);
resourceUpdates->updateDynamicBuffer(ubuf.get(), 64, 16, &color);
cb->resourceUpdate(resourceUpdates);
mainViewport = data.getPipelineState().viewport;
}
void ConsumerRenderer::render(QSSGFrameData &data)
{
if (!canRender)
return;
const std::unique_ptr<QSSGRhiContext> &rhiCtx = data.contextInterface()->rhiContext();
if (!rhiCtx)
return;
QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
cb->debugMarkBegin(QByteArrayLiteral("Custom rhi rendering (consumer)"));
cb->setGraphicsPipeline(ps.get());
cb->setViewport(mainViewport);
cb->setShaderResources();
const QRhiCommandBuffer::VertexInput vbufBindings[] = {
{ vbuf.get(), 0 },
{ vbuf.get(), quint32(36 * 3 * sizeof(float)) }
};
cb->setVertexInput(0, 2, vbufBindings);
cb->draw(36);
cb->debugMarkEnd();
}
void ConsumerRenderer::resetForFrame()
{
}
MyExtension::MyExtension(QQuick3DObject *parent)
: QQuick3DRenderExtension(parent)
{
m_producer = new ProducerExtension(this);
// Calling update() on m_producer in updateSpatialNode() would be bad: that
// would mean the producer only saw every *other* change. Instead,
// trigger update() via the changed signals.
QObject::connect(this, &MyExtension::subSceneRotationChanged, m_producer, &ProducerExtension::update);
}
QSSGRenderGraphObject *MyExtension::updateSpatialNode(QSSGRenderGraphObject *node)
{
if (!node)
node = new ConsumerRenderer(m_producer);
ConsumerRenderer *renderer = static_cast<ConsumerRenderer *>(node);
if (m_dirtyFlag & PositionDirty)
renderer->updateModelMatrix(QVector3D(m_x, m_y, m_z));
if (m_dirtyFlag & SubSceneRotationDirty)
renderer->producer->rotation = m_subSceneRotation;
m_dirtyFlag = {};
return node;
}
void MyExtension::markDirty(Dirty v)
{
m_dirtyFlag |= v;
update();
}