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++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "examplewidget.h"
++ #include "cube.h"
++
++ #include <QFile>
++ #include <QPainter>
++ #include <QtGui/qquaternion.h>
++
++ static const QSize CUBE_TEX_SIZE(512, 512);
++
++ ExampleRhiWidget::ExampleRhiWidget(QWidget *parent)
++ : QRhiWidget(parent)
++ {
++ }
++
++ //![init-1]
++ void ExampleRhiWidget::initialize(QRhiCommandBuffer *)
++ {
++ if (m_rhi != rhi()) {
++ m_rhi = rhi();
++ scene = {};
++ emit rhiChanged(QString::fromUtf8(m_rhi->backendName()));
++ }
++ if (m_pixelSize != renderTarget()->pixelSize()) {
++ m_pixelSize = renderTarget()->pixelSize();
++ emit resized();
++ }
++ if (m_sampleCount != renderTarget()->sampleCount()) {
++ m_sampleCount = renderTarget()->sampleCount();
++ scene = {};
++ }
++ //![init-1]
++
++ //![init-2]
++ if (!scene.vbuf) {
++ initScene();
++ updateCubeTexture();
++ }
++
++ scene.mvp = m_rhi->clipSpaceCorrMatrix();
++ scene.mvp.perspective(45.0f, m_pixelSize.width() / (float) m_pixelSize.height(), 0.01f, 1000.0f);
++ scene.mvp.translate(0, 0, -4);
++ updateMvp();
++ }
++ //![init-2]
++
++ //![rotation-update]
++ void ExampleRhiWidget::updateMvp()
++ {
++ QMatrix4x4 mvp = scene.mvp * QMatrix4x4(QQuaternion::fromEulerAngles(QVector3D(30, itemData.cubeRotation, 0)).toRotationMatrix());
++ if (!scene.resourceUpdates)
++ scene.resourceUpdates = m_rhi->nextResourceUpdateBatch();
++ scene.resourceUpdates->updateDynamicBuffer(scene.ubuf.get(), 0, 64, mvp.constData());
++ }
++ //![rotation-update]
++
++ //![texture-update]
++ void ExampleRhiWidget::updateCubeTexture()
++ {
++ QImage image(CUBE_TEX_SIZE, QImage::Format_RGBA8888);
++ const QRect r(QPoint(0, 0), CUBE_TEX_SIZE);
++ QPainter p(&image);
++ p.fillRect(r, QGradient::DeepBlue);
++ QFont font;
++ font.setPointSize(24);
++ p.setFont(font);
++ p.drawText(r, itemData.cubeText);
++ p.end();
++
++ if (!scene.resourceUpdates)
++ scene.resourceUpdates = m_rhi->nextResourceUpdateBatch();
++ scene.resourceUpdates->uploadTexture(scene.cubeTex.get(), image);
++ }
++ //![texture-update]
++
++ static QShader getShader(const QString &name)
++ {
++ QFile f(name);
++ return f.open(QIODevice::ReadOnly) ? QShader::fromSerialized(f.readAll()) : QShader();
++ }
++
++ void ExampleRhiWidget::initScene()
++ {
++ //![setup-scene]
++ scene.vbuf.reset(m_rhi->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(cube)));
++ scene.vbuf->create();
++
++ scene.resourceUpdates = m_rhi->nextResourceUpdateBatch();
++ scene.resourceUpdates->uploadStaticBuffer(scene.vbuf.get(), cube);
++
++ scene.ubuf.reset(m_rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 64));
++ scene.ubuf->create();
++
++ scene.cubeTex.reset(m_rhi->newTexture(QRhiTexture::RGBA8, CUBE_TEX_SIZE));
++ scene.cubeTex->create();
++
++ scene.sampler.reset(m_rhi->newSampler(QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
++ QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge));
++ scene.sampler->create();
++
++ scene.srb.reset(m_rhi->newShaderResourceBindings());
++ scene.srb->setBindings({
++ QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage, scene.ubuf.get()),
++ QRhiShaderResourceBinding::sampledTexture(1, QRhiShaderResourceBinding::FragmentStage, scene.cubeTex.get(), scene.sampler.get())
++ });
++ scene.srb->create();
++
++ scene.ps.reset(m_rhi->newGraphicsPipeline());
++ scene.ps->setDepthTest(true);
++ scene.ps->setDepthWrite(true);
++ scene.ps->setCullMode(QRhiGraphicsPipeline::Back);
++ scene.ps->setShaderStages({
++ { QRhiShaderStage::Vertex, getShader(QLatin1String(":/shader_assets/texture.vert.qsb")) },
++ { QRhiShaderStage::Fragment, getShader(QLatin1String(":/shader_assets/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 }
++ });
++ scene.ps->setSampleCount(m_sampleCount);
++ scene.ps->setVertexInputLayout(inputLayout);
++ scene.ps->setShaderResourceBindings(scene.srb.get());
++ scene.ps->setRenderPassDescriptor(renderTarget()->renderPassDescriptor());
++ scene.ps->create();
++ //![setup-scene]
++ }
++
++ //![render]
++ void ExampleRhiWidget::render(QRhiCommandBuffer *cb)
++ {
++ if (itemData.cubeRotationDirty) {
++ itemData.cubeRotationDirty = false;
++ updateMvp();
++ }
++
++ if (itemData.cubeTextDirty) {
++ itemData.cubeTextDirty = false;
++ updateCubeTexture();
++ }
++
++ QRhiResourceUpdateBatch *resourceUpdates = scene.resourceUpdates;
++ if (resourceUpdates)
++ scene.resourceUpdates = nullptr;
++
++ const QColor clearColor = QColor::fromRgbF(0.4f, 0.7f, 0.0f, 1.0f);
++ cb->beginPass(renderTarget(), clearColor, { 1.0f, 0 }, resourceUpdates);
++
++ cb->setGraphicsPipeline(scene.ps.get());
++ cb->setViewport(QRhiViewport(0, 0, m_pixelSize.width(), m_pixelSize.height()));
++ cb->setShaderResources();
++ const QRhiCommandBuffer::VertexInput vbufBindings[] = {
++ { scene.vbuf.get(), 0 },
++ { scene.vbuf.get(), quint32(36 * 3 * sizeof(float)) }
++ };
++ cb->setVertexInput(0, 2, vbufBindings);
++ cb->draw(36);
++
++ cb->endPass();
++ }
++ //![render]
++
++ void ExampleRhiWidget::releaseResources()
++ {
++ scene = {}; // a subsequent initialize() will recreate everything
++ }