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++ // Copyright (C) 2020 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "rhiwindow.h"
++ #include <QPlatformSurfaceEvent>
++ #include <QPainter>
++ #include <QFile>
++ #include <rhi/qshader.h>
++
++ //! [rhiwindow-ctor]
++ RhiWindow::RhiWindow(QRhi::Implementation graphicsApi)
++ : m_graphicsApi(graphicsApi)
++ {
++ switch (graphicsApi) {
++ case QRhi::OpenGLES2:
++ setSurfaceType(OpenGLSurface);
++ break;
++ case QRhi::Vulkan:
++ setSurfaceType(VulkanSurface);
++ break;
++ case QRhi::D3D11:
++ case QRhi::D3D12:
++ setSurfaceType(Direct3DSurface);
++ break;
++ case QRhi::Metal:
++ setSurfaceType(MetalSurface);
++ break;
++ case QRhi::Null:
++ break; // RasterSurface
++ }
++ }
++ //! [rhiwindow-ctor]
++
++ QString RhiWindow::graphicsApiName() const
++ {
++ switch (m_graphicsApi) {
++ case QRhi::Null:
++ return QLatin1String("Null (no output)");
++ case QRhi::OpenGLES2:
++ return QLatin1String("OpenGL");
++ case QRhi::Vulkan:
++ return QLatin1String("Vulkan");
++ case QRhi::D3D11:
++ return QLatin1String("Direct3D 11");
++ case QRhi::D3D12:
++ return QLatin1String("Direct3D 12");
++ case QRhi::Metal:
++ return QLatin1String("Metal");
++ }
++ return QString();
++ }
++
++ //! [expose]
++ void RhiWindow::exposeEvent(QExposeEvent *)
++ {
++ // initialize and start rendering when the window becomes usable for graphics purposes
++ if (isExposed() && !m_initialized) {
++ init();
++ resizeSwapChain();
++ m_initialized = true;
++ }
++
++ const QSize surfaceSize = m_hasSwapChain ? m_sc->surfacePixelSize() : QSize();
++
++ // stop pushing frames when not exposed (or size is 0)
++ if ((!isExposed() || (m_hasSwapChain && surfaceSize.isEmpty())) && m_initialized && !m_notExposed)
++ m_notExposed = true;
++
++ // Continue when exposed again and the surface has a valid size. Note that
++ // surfaceSize can be (0, 0) even though size() reports a valid one, hence
++ // trusting surfacePixelSize() and not QWindow.
++ if (isExposed() && m_initialized && m_notExposed && !surfaceSize.isEmpty()) {
++ m_notExposed = false;
++ m_newlyExposed = true;
++ }
++
++ // always render a frame on exposeEvent() (when exposed) in order to update
++ // immediately on window resize.
++ if (isExposed() && !surfaceSize.isEmpty())
++ render();
++ }
++ //! [expose]
++
++ //! [event]
++ bool RhiWindow::event(QEvent *e)
++ {
++ switch (e->type()) {
++ case QEvent::UpdateRequest:
++ render();
++ break;
++
++ case QEvent::PlatformSurface:
++ // this is the proper time to tear down the swapchain (while the native window and surface are still around)
++ if (static_cast<QPlatformSurfaceEvent *>(e)->surfaceEventType() == QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed)
++ releaseSwapChain();
++ break;
++
++ default:
++ break;
++ }
++
++ return QWindow::event(e);
++ }
++ //! [event]
++
++ //! [rhi-init]
++ void RhiWindow::init()
++ {
++ if (m_graphicsApi == QRhi::Null) {
++ QRhiNullInitParams params;
++ m_rhi.reset(QRhi::create(QRhi::Null, ¶ms));
++ }
++
++ #if QT_CONFIG(opengl)
++ if (m_graphicsApi == QRhi::OpenGLES2) {
++ m_fallbackSurface.reset(QRhiGles2InitParams::newFallbackSurface());
++ QRhiGles2InitParams params;
++ params.fallbackSurface = m_fallbackSurface.get();
++ params.window = this;
++ m_rhi.reset(QRhi::create(QRhi::OpenGLES2, ¶ms));
++ }
++ #endif
++
++ #if QT_CONFIG(vulkan)
++ if (m_graphicsApi == QRhi::Vulkan) {
++ QRhiVulkanInitParams params;
++ params.inst = vulkanInstance();
++ params.window = this;
++ m_rhi.reset(QRhi::create(QRhi::Vulkan, ¶ms));
++ }
++ #endif
++
++ #ifdef Q_OS_WIN
++ if (m_graphicsApi == QRhi::D3D11) {
++ QRhiD3D11InitParams params;
++ // Enable the debug layer, if available. This is optional
++ // and should be avoided in production builds.
++ params.enableDebugLayer = true;
++ m_rhi.reset(QRhi::create(QRhi::D3D11, ¶ms));
++ } else if (m_graphicsApi == QRhi::D3D12) {
++ QRhiD3D12InitParams params;
++ // Enable the debug layer, if available. This is optional
++ // and should be avoided in production builds.
++ params.enableDebugLayer = true;
++ m_rhi.reset(QRhi::create(QRhi::D3D12, ¶ms));
++ }
++ #endif
++
++ #if QT_CONFIG(metal)
++ if (m_graphicsApi == QRhi::Metal) {
++ QRhiMetalInitParams params;
++ m_rhi.reset(QRhi::create(QRhi::Metal, ¶ms));
++ }
++ #endif
++
++ if (!m_rhi)
++ qFatal("Failed to create RHI backend");
++ //! [rhi-init]
++
++ //! [swapchain-init]
++ m_sc.reset(m_rhi->newSwapChain());
++ m_ds.reset(m_rhi->newRenderBuffer(QRhiRenderBuffer::DepthStencil,
++ QSize(), // no need to set the size here, due to UsedWithSwapChainOnly
++ 1,
++ QRhiRenderBuffer::UsedWithSwapChainOnly));
++ m_sc->setWindow(this);
++ m_sc->setDepthStencil(m_ds.get());
++ m_rp.reset(m_sc->newCompatibleRenderPassDescriptor());
++ m_sc->setRenderPassDescriptor(m_rp.get());
++ //! [swapchain-init]
++
++ customInit();
++ }
++
++ //! [swapchain-resize]
++ void RhiWindow::resizeSwapChain()
++ {
++ m_hasSwapChain = m_sc->createOrResize(); // also handles m_ds
++
++ const QSize outputSize = m_sc->currentPixelSize();
++ 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);
++ }
++ //! [swapchain-resize]
++
++ void RhiWindow::releaseSwapChain()
++ {
++ if (m_hasSwapChain) {
++ m_hasSwapChain = false;
++ m_sc->destroy();
++ }
++ }
++
++ //! [render-precheck]
++ void RhiWindow::render()
++ {
++ if (!m_hasSwapChain || m_notExposed)
++ return;
++ //! [render-precheck]
++
++ //! [render-resize]
++ // If the window got resized or newly exposed, resize the swapchain. (the
++ // newly-exposed case is not actually required by some platforms, but is
++ // here for robustness and portability)
++ //
++ // This (exposeEvent + the logic here) is the only safe way to perform
++ // resize handling. Note the usage of the RHI's surfacePixelSize(), and
++ // never QWindow::size(). (the two may or may not be the same under the hood,
++ // depending on the backend and platform)
++ //
++ if (m_sc->currentPixelSize() != m_sc->surfacePixelSize() || m_newlyExposed) {
++ resizeSwapChain();
++ if (!m_hasSwapChain)
++ return;
++ m_newlyExposed = false;
++ }
++ //! [render-resize]
++
++ //! [beginframe]
++ QRhi::FrameOpResult result = m_rhi->beginFrame(m_sc.get());
++ if (result == QRhi::FrameOpSwapChainOutOfDate) {
++ resizeSwapChain();
++ if (!m_hasSwapChain)
++ return;
++ result = m_rhi->beginFrame(m_sc.get());
++ }
++ if (result != QRhi::FrameOpSuccess) {
++ qWarning("beginFrame failed with %d, will retry", result);
++ requestUpdate();
++ return;
++ }
++
++ customRender();
++ //! [beginframe]
++
++ //! [request-update]
++ m_rhi->endFrame(m_sc.get());
++
++ // Always request the next frame via requestUpdate(). On some platforms this is backed
++ // by a platform-specific solution, e.g. CVDisplayLink on macOS, which is potentially
++ // more efficient than a timer, queued metacalls, etc.
++ requestUpdate();
++ }
++ //! [request-update]
++
++ static float vertexData[] = {
++ // Y up (note clipSpaceCorrMatrix in m_viewProjection), CCW
++ 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,
++ };
++
++ //! [getshader]
++ static QShader getShader(const QString &name)
++ {
++ QFile f(name);
++ if (f.open(QIODevice::ReadOnly))
++ return QShader::fromSerialized(f.readAll());
++
++ return QShader();
++ }
++ //! [getshader]
++
++ HelloWindow::HelloWindow(QRhi::Implementation graphicsApi)
++ : RhiWindow(graphicsApi)
++ {
++ }
++
++ //! [ensure-texture]
++ void HelloWindow::ensureFullscreenTexture(const QSize &pixelSize, QRhiResourceUpdateBatch *u)
++ {
++ if (m_texture && m_texture->pixelSize() == pixelSize)
++ return;
++
++ if (!m_texture)
++ m_texture.reset(m_rhi->newTexture(QRhiTexture::RGBA8, pixelSize));
++ else
++ m_texture->setPixelSize(pixelSize);
++
++ m_texture->create();
++
++ QImage image(pixelSize, QImage::Format_RGBA8888_Premultiplied);
++ image.setDevicePixelRatio(devicePixelRatio());
++ //! [ensure-texture]
++ QPainter painter(&image);
++ painter.fillRect(QRectF(QPointF(0, 0), size()), QColor::fromRgbF(0.4f, 0.7f, 0.0f, 1.0f));
++ painter.setPen(Qt::transparent);
++ painter.setBrush({ QGradient(QGradient::DeepBlue) });
++ painter.drawRoundedRect(QRectF(QPointF(20, 20), size() - QSize(40, 40)), 16, 16);
++ painter.setPen(Qt::black);
++ QFont font;
++ font.setPixelSize(0.05 * qMin(width(), height()));
++ painter.setFont(font);
++ painter.drawText(QRectF(QPointF(60, 60), size() - QSize(120, 120)), 0,
++ QLatin1String("Rendering with QRhi to a resizable QWindow.\nThe 3D API is %1.\nUse the command-line options to choose a different API.")
++ .arg(graphicsApiName()));
++ painter.end();
++
++ if (m_rhi->isYUpInNDC())
++ image.flip();
++
++ //! [ensure-texture-2]
++ u->uploadTexture(m_texture.get(), image);
++ //! [ensure-texture-2]
++ }
++
++ //! [render-init-1]
++ void HelloWindow::customInit()
++ {
++ m_initialUpdates = m_rhi->nextResourceUpdateBatch();
++
++ m_vbuf.reset(m_rhi->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(vertexData)));
++ m_vbuf->create();
++ m_initialUpdates->uploadStaticBuffer(m_vbuf.get(), vertexData);
++
++ static const quint32 UBUF_SIZE = 68;
++ m_ubuf.reset(m_rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, UBUF_SIZE));
++ m_ubuf->create();
++ //! [render-init-1]
++
++ ensureFullscreenTexture(m_sc->surfacePixelSize(), m_initialUpdates);
++
++ m_sampler.reset(m_rhi->newSampler(QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
++ QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge));
++ m_sampler->create();
++
++ //! [render-init-2]
++ m_colorTriSrb.reset(m_rhi->newShaderResourceBindings());
++ static const QRhiShaderResourceBinding::StageFlags visibility =
++ QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage;
++ m_colorTriSrb->setBindings({
++ QRhiShaderResourceBinding::uniformBuffer(0, visibility, m_ubuf.get())
++ });
++ m_colorTriSrb->create();
++
++ m_colorPipeline.reset(m_rhi->newGraphicsPipeline());
++ // Enable depth testing; not quite needed for a simple triangle, but we
++ // have a depth-stencil buffer so why not.
++ m_colorPipeline->setDepthTest(true);
++ m_colorPipeline->setDepthWrite(true);
++ // Blend factors default to One, OneOneMinusSrcAlpha, which is convenient.
++ QRhiGraphicsPipeline::TargetBlend premulAlphaBlend;
++ premulAlphaBlend.enable = true;
++ m_colorPipeline->setTargetBlends({ premulAlphaBlend });
++ m_colorPipeline->setShaderStages({
++ { QRhiShaderStage::Vertex, getShader(QLatin1String(":/color.vert.qsb")) },
++ { QRhiShaderStage::Fragment, getShader(QLatin1String(":/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_colorPipeline->setVertexInputLayout(inputLayout);
++ m_colorPipeline->setShaderResourceBindings(m_colorTriSrb.get());
++ m_colorPipeline->setRenderPassDescriptor(m_rp.get());
++ m_colorPipeline->create();
++ //! [render-init-2]
++
++ m_fullscreenQuadSrb.reset(m_rhi->newShaderResourceBindings());
++ m_fullscreenQuadSrb->setBindings({
++ QRhiShaderResourceBinding::sampledTexture(0, QRhiShaderResourceBinding::FragmentStage,
++ m_texture.get(), m_sampler.get())
++ });
++ m_fullscreenQuadSrb->create();
++
++ m_fullscreenQuadPipeline.reset(m_rhi->newGraphicsPipeline());
++ m_fullscreenQuadPipeline->setShaderStages({
++ { QRhiShaderStage::Vertex, getShader(QLatin1String(":/quad.vert.qsb")) },
++ { QRhiShaderStage::Fragment, getShader(QLatin1String(":/quad.frag.qsb")) }
++ });
++ m_fullscreenQuadPipeline->setVertexInputLayout({});
++ m_fullscreenQuadPipeline->setShaderResourceBindings(m_fullscreenQuadSrb.get());
++ m_fullscreenQuadPipeline->setRenderPassDescriptor(m_rp.get());
++ m_fullscreenQuadPipeline->create();
++ }
++
++ //! [render-1]
++ void HelloWindow::customRender()
++ {
++ QRhiResourceUpdateBatch *resourceUpdates = m_rhi->nextResourceUpdateBatch();
++
++ if (m_initialUpdates) {
++ resourceUpdates->merge(m_initialUpdates);
++ m_initialUpdates->release();
++ m_initialUpdates = nullptr;
++ }
++ //! [render-1]
++
++ //! [render-rotation]
++ m_rotation += 1.0f;
++ QMatrix4x4 modelViewProjection = m_viewProjection;
++ modelViewProjection.rotate(m_rotation, 0, 1, 0);
++ resourceUpdates->updateDynamicBuffer(m_ubuf.get(), 0, 64, modelViewProjection.constData());
++ //! [render-rotation]
++
++ //! [render-opacity]
++ m_opacity += m_opacityDir * 0.005f;
++ if (m_opacity < 0.0f || m_opacity > 1.0f) {
++ m_opacityDir *= -1;
++ m_opacity = qBound(0.0f, m_opacity, 1.0f);
++ }
++ resourceUpdates->updateDynamicBuffer(m_ubuf.get(), 64, 4, &m_opacity);
++ //! [render-opacity]
++
++ //! [render-cb]
++ QRhiCommandBuffer *cb = m_sc->currentFrameCommandBuffer();
++ const QSize outputSizeInPixels = m_sc->currentPixelSize();
++ //! [render-cb]
++
++ // (re)create the texture with a size matching the output surface size, when necessary.
++ ensureFullscreenTexture(outputSizeInPixels, resourceUpdates);
++
++ //! [render-pass]
++ cb->beginPass(m_sc->currentFrameRenderTarget(), Qt::black, { 1.0f, 0 }, resourceUpdates);
++ //! [render-pass]
++
++ cb->setGraphicsPipeline(m_fullscreenQuadPipeline.get());
++ cb->setViewport({ 0, 0, float(outputSizeInPixels.width()), float(outputSizeInPixels.height()) });
++ cb->setShaderResources();
++ cb->draw(3);
++
++ //! [render-pass-record]
++ cb->setGraphicsPipeline(m_colorPipeline.get());
++ cb->setShaderResources();
++ const QRhiCommandBuffer::VertexInput vbufBinding(m_vbuf.get(), 0);
++ cb->setVertexInput(0, 1, &vbufBinding);
++ cb->draw(3);
++
++ cb->endPass();
++ //! [render-pass-record]
++ }