1 files changed, 147 insertions, 0 deletions
diff --git a/src/quick/doc/snippets/qquickrhiitem/qquickrhiitem_intro.cpp b/src/quick/doc/snippets/qquickrhiitem/qquickrhiitem_intro.cpp
new file mode 100644
index 0000000000..3a3d1585bf
--- /dev/null
+++ b/src/quick/doc/snippets/qquickrhiitem/qquickrhiitem_intro.cpp
@@ -0,0 +1,147 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtQuick/QQuickRhiItem>
+#include <rhi/qrhi.h>
+
+//![0]
+class ExampleRhiItemRenderer : public QQuickRhiItemRenderer
+{
+public:
+    void initialize(QRhiCommandBuffer *cb) override;
+    void synchronize(QQuickRhiItem *item) override;
+    void render(QRhiCommandBuffer *cb) override;
+
+private:
+    QRhi *m_rhi = nullptr;
+    std::unique_ptr<QRhiBuffer> m_vbuf;
+    std::unique_ptr<QRhiBuffer> m_ubuf;
+    std::unique_ptr<QRhiShaderResourceBindings> m_srb;
+    std::unique_ptr<QRhiGraphicsPipeline> m_pipeline;
+    QMatrix4x4 m_viewProjection;
+    float m_angle = 0.0f;
+};
+
+class ExampleRhiItem : public QQuickRhiItem
+{
+    Q_OBJECT
+    QML_NAMED_ELEMENT(ExampleRhiItem)
+    Q_PROPERTY(float angle READ angle WRITE setAngle NOTIFY angleChanged)
+
+public:
+    QQuickRhiItemRenderer *createRenderer() override;
+
+    float angle() const { return m_angle; }
+    void setAngle(float a);
+
+signals:
+    void angleChanged();
+
+private:
+    float m_angle = 0.0f;
+};
+
+QQuickRhiItemRenderer *ExampleRhiItem::createRenderer()
+{
+    return new ExampleRhiItemRenderer;
+}
+
+void ExampleRhiItem::setAngle(float a)
+{
+    if (m_angle == a)
+        return;
+
+    m_angle = a;
+    emit angleChanged();
+    update();
+}
+
+void ExampleRhiItemRenderer::synchronize(QQuickRhiItem *rhiItem)
+{
+    ExampleRhiItem *item = static_cast<ExampleRhiItem *>(rhiItem);
+    if (item->angle() != m_angle)
+        m_angle = item->angle();
+}
+
+static QShader getShader(const QString &name)
+{
+    QFile f(name);
+    return f.open(QIODevice::ReadOnly) ? QShader::fromSerialized(f.readAll()) : QShader();
+}
+
+static float vertexData[] = {
+    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 ExampleRhiItemRenderer::initialize(QRhiCommandBuffer *cb)
+{
+    if (m_rhi != rhi()) {
+        m_pipeline.reset();
+        m_rhi = rhi();
+    }
+
+    if (!m_pipeline) {
+        m_vbuf.reset(m_rhi->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(vertexData)));
+        m_vbuf->create();
+
+        m_ubuf.reset(m_rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 64));
+        m_ubuf->create();
+
+        m_srb.reset(m_rhi->newShaderResourceBindings());
+        m_srb->setBindings({
+            QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage, m_ubuf.get()),
+        });
+        m_srb->create();
+
+        m_pipeline.reset(m_rhi->newGraphicsPipeline());
+        m_pipeline->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) }
+        });
+        m_pipeline->setVertexInputLayout(inputLayout);
+        m_pipeline->setShaderResourceBindings(m_srb.get());
+        m_pipeline->setRenderPassDescriptor(renderTarget()->renderPassDescriptor());
+        m_pipeline->create();
+
+        QRhiResourceUpdateBatch *resourceUpdates = m_rhi->nextResourceUpdateBatch();
+        resourceUpdates->uploadStaticBuffer(m_vbuf.get(), vertexData);
+        cb->resourceUpdate(resourceUpdates);
+    }
+
+    const QSize outputSize = renderTarget()->pixelSize();
+    m_viewProjection = m_rhi->clipSpaceCorrMatrix();
+    m_viewProjection.perspective(45.0f, outputSize.width() / (float) outputSize.height(), 0.01f, 1000.0f);
+    m_viewProjection.translate(0, 0, -4);
+}
+
+void ExampleRhiItemRenderer::render(QRhiCommandBuffer *cb)
+{
+    QRhiResourceUpdateBatch *resourceUpdates = m_rhi->nextResourceUpdateBatch();
+    QMatrix4x4 modelViewProjection = m_viewProjection;
+    modelViewProjection.rotate(m_angle, 0, 1, 0);
+    resourceUpdates->updateDynamicBuffer(m_ubuf.get(), 0, 64, modelViewProjection.constData());
+
+    const QColor clearColor = QColor::fromRgbF(0.4f, 0.7f, 0.0f, 1.0f);
+    cb->beginPass(renderTarget(), clearColor, { 1.0f, 0 }, resourceUpdates);
+
+    cb->setGraphicsPipeline(m_pipeline.get());
+    const QSize outputSize = renderTarget()->pixelSize();
+    cb->setViewport(QRhiViewport(0, 0, outputSize.width(), outputSize.height()));
+    cb->setShaderResources();
+    const QRhiCommandBuffer::VertexInput vbufBinding(m_vbuf.get(), 0);
+    cb->setVertexInput(0, 1, &vbufBinding);
+    cb->draw(3);
+
+    cb->endPass();
+}
+//![0]