qt5base-lts/tests/manual/rhi/multiwindow/multiwindow.cpp
Laszlo Agocs 86876744f0 Ensure drawable size atomicity within a frame
Revert surfacePixelSize() to be a getter only. With Metal this will
mean returning the "live" layer size (and so not the
layer.drawableSize), which is in line with what we expect with other
backends.

Instead, we leave it to the swapchain's buildOrResize() to "commit"
the size by setting drawableSize on the layer. With typical
application or Qt Quick logic this ensures that layer.drawableSize is
set once and stays static until we get to process the next resize - on
the rendering thread.

This of course would still mean that there was a race when a client
queries surfacePixelSize() to set the depth-stencil buffer size that
is associated with a swapchain. (because that must happen before
calling buildOrResize() according to the current semantics)

That can however be solved in a quite elegant way, it turns out,
because we already have a flag that indicates if a QRhiRenderBuffer is
used in combination with (and only in combination with) a
swapchain. If we simply say that setting the UsedWithSwapChainOnly
flag provides automatic sizing as well (so no setPixelSize() call is
needed), clients can simply get rid of the problematic
surfacePixelSize() query and everything works.

Task-number: QTBUG-78641
Change-Id: Ib1bfc9ef8531bcce033d1f1e5d4d5b4984d6d69f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
2019-09-29 22:16:55 +02:00

641 lines
19 KiB
C++

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#include <QApplication>
#include <QWidget>
#include <QLabel>
#include <QPlainTextEdit>
#include <QPushButton>
#include <QCheckBox>
#include <QVBoxLayout>
#include <QCommandLineParser>
#include <QWindow>
#include <QPlatformSurfaceEvent>
#include <QElapsedTimer>
#include <QtGui/private/qshader_p.h>
#include <QFile>
#ifndef QT_NO_OPENGL
#include <QtGui/private/qrhigles2_p.h>
#include <QOffscreenSurface>
#endif
#if QT_CONFIG(vulkan)
#include <QLoggingCategory>
#include <QtGui/private/qrhivulkan_p.h>
#endif
#ifdef Q_OS_WIN
#include <QtGui/private/qrhid3d11_p.h>
#endif
#ifdef Q_OS_DARWIN
#include <QtGui/private/qrhimetal_p.h>
#endif
enum GraphicsApi
{
OpenGL,
Vulkan,
D3D11,
Metal
};
static GraphicsApi graphicsApi;
static QString graphicsApiName()
{
switch (graphicsApi) {
case OpenGL:
return QLatin1String("OpenGL 2.x");
case Vulkan:
return QLatin1String("Vulkan");
case D3D11:
return QLatin1String("Direct3D 11");
case Metal:
return QLatin1String("Metal");
default:
break;
}
return QString();
}
static struct {
#if QT_CONFIG(vulkan)
QVulkanInstance *instance = nullptr;
#endif
QRhi *r = nullptr;
#ifndef QT_NO_OPENGL
QOffscreenSurface *fallbackSurface = nullptr;
#endif
} r;
void createRhi()
{
#ifndef QT_NO_OPENGL
if (graphicsApi == OpenGL) {
r.fallbackSurface = QRhiGles2InitParams::newFallbackSurface();
QRhiGles2InitParams params;
params.fallbackSurface = r.fallbackSurface;
//params.window = this;
r.r = QRhi::create(QRhi::OpenGLES2, &params);
}
#endif
#if QT_CONFIG(vulkan)
if (graphicsApi == Vulkan) {
QRhiVulkanInitParams params;
params.inst = r.instance;
//params.window = this;
r.r = QRhi::create(QRhi::Vulkan, &params);
}
#endif
#ifdef Q_OS_WIN
if (graphicsApi == D3D11) {
QRhiD3D11InitParams params;
params.enableDebugLayer = true;
r.r = QRhi::create(QRhi::D3D11, &params);
}
#endif
#ifdef Q_OS_DARWIN
if (graphicsApi == Metal) {
QRhiMetalInitParams params;
r.r = QRhi::create(QRhi::Metal, &params);
}
#endif
if (!r.r)
qFatal("Failed to create RHI backend");
}
void destroyRhi()
{
delete r.r;
#ifndef QT_NO_OPENGL
delete r.fallbackSurface;
#endif
}
struct {
QVector<QWindow *> windows;
QRhiBuffer *vbuf = nullptr;
QRhiBuffer *ubuf = nullptr;
QRhiShaderResourceBindings *srb = nullptr;
QRhiGraphicsPipeline *ps = nullptr;
QRhiResourceUpdateBatch *initialUpdates = nullptr;
} d;
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,
};
static QShader getShader(const QString &name)
{
QFile f(name);
if (f.open(QIODevice::ReadOnly))
return QShader::fromSerialized(f.readAll());
return QShader();
}
// can use just one rpd from whichever window comes first since they are
// actually compatible due to all windows using the same config (have
// depth-stencil, sample count 1, same format). this means the same pso can be
// reused too.
void ensureSharedResources(QRhiRenderPassDescriptor *rp)
{
if (!d.vbuf) {
d.vbuf = r.r->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(vertexData));
d.vbuf->build();
d.initialUpdates = r.r->nextResourceUpdateBatch();
d.initialUpdates->uploadStaticBuffer(d.vbuf, vertexData);
}
if (!d.ubuf) {
d.ubuf = r.r->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 68);
d.ubuf->build();
}
if (!d.srb) {
d.srb = r.r->newShaderResourceBindings();
d.srb->setBindings({
QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage, d.ubuf)
});
d.srb->build();
}
if (!d.ps) {
d.ps = r.r->newGraphicsPipeline();
QRhiGraphicsPipeline::TargetBlend premulAlphaBlend;
premulAlphaBlend.enable = true;
d.ps->setTargetBlends({ premulAlphaBlend });
const QShader vs = getShader(QLatin1String(":/color.vert.qsb"));
if (!vs.isValid())
qFatal("Failed to load shader pack (vertex)");
const QShader fs = getShader(QLatin1String(":/color.frag.qsb"));
if (!fs.isValid())
qFatal("Failed to load shader pack (fragment)");
d.ps->setShaderStages({
{ QRhiShaderStage::Vertex, vs },
{ QRhiShaderStage::Fragment, fs }
});
QRhiVertexInputLayout inputLayout;
inputLayout.setBindings({
{ 5 * sizeof(float) }
});
inputLayout.setAttributes({
{ 0, 0, QRhiVertexInputAttribute::Float2, 0 },
{ 0, 1, QRhiVertexInputAttribute::Float3, 2 * sizeof(float) }
});
d.ps->setVertexInputLayout(inputLayout);
d.ps->setShaderResourceBindings(d.srb);
d.ps->setRenderPassDescriptor(rp);
d.ps->build();
}
}
void destroySharedResources()
{
delete d.ps;
d.ps = nullptr;
delete d.srb;
d.srb = nullptr;
delete d.vbuf;
d.vbuf = nullptr;
delete d.ubuf;
d.ubuf = nullptr;
}
class Window : public QWindow
{
public:
Window(const QString &title, const QColor &bgColor, int axis, bool noVSync);
~Window();
protected:
void init();
void releaseResources();
void resizeSwapChain();
void releaseSwapChain();
void render();
void exposeEvent(QExposeEvent *) override;
bool event(QEvent *) override;
QColor m_bgColor;
int m_rotationAxis;
bool m_noVSync;
bool m_running = false;
bool m_notExposed = false;
bool m_newlyExposed = false;
QMatrix4x4 m_proj;
QVector<QRhiResource *> m_releasePool;
bool m_hasSwapChain = false;
QRhiSwapChain *m_sc = nullptr;
QRhiRenderBuffer *m_ds = nullptr;
QRhiRenderPassDescriptor *m_rp = nullptr;
float m_rotation = 0;
float m_opacity = 1;
int m_opacityDir = -1;
};
Window::Window(const QString &title, const QColor &bgColor, int axis, bool noVSync)
: m_bgColor(bgColor),
m_rotationAxis(axis),
m_noVSync(noVSync)
{
switch (graphicsApi) {
case OpenGL:
{
#if QT_CONFIG(opengl)
setSurfaceType(OpenGLSurface);
QSurfaceFormat fmt = QRhiGles2InitParams::adjustedFormat(); // default + depth/stencil
fmt.setSwapInterval(noVSync ? 0 : 1); // + swap interval
setFormat(fmt);
#endif
}
break;
case Vulkan:
#if QT_CONFIG(vulkan)
setSurfaceType(VulkanSurface);
setVulkanInstance(r.instance);
#endif
break;
case D3D11:
setSurfaceType(OpenGLSurface); // not a typo
break;
case Metal:
#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
setSurfaceType(MetalSurface);
#endif
break;
default:
break;
}
resize(800, 600);
setTitle(title);
}
Window::~Window()
{
releaseResources();
}
void Window::exposeEvent(QExposeEvent *)
{
// initialize and start rendering when the window becomes usable for graphics purposes
if (isExposed() && !m_running) {
m_running = true;
init();
resizeSwapChain();
}
// stop pushing frames when not exposed (or size is 0)
if ((!isExposed() || (m_hasSwapChain && m_sc->surfacePixelSize().isEmpty())) && m_running)
m_notExposed = true;
// continue when exposed again and the surface has a valid size.
// note that the surface size can be (0, 0) even though size() reports a valid one...
if (isExposed() && m_running && m_notExposed && !m_sc->surfacePixelSize().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() && !m_sc->surfacePixelSize().isEmpty())
render();
}
bool Window::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);
}
void Window::init()
{
m_sc = r.r->newSwapChain();
m_ds = r.r->newRenderBuffer(QRhiRenderBuffer::DepthStencil,
QSize(),
1,
QRhiRenderBuffer::UsedWithSwapChainOnly);
m_releasePool << m_ds;
m_sc->setWindow(this);
m_sc->setDepthStencil(m_ds);
if (m_noVSync)
m_sc->setFlags(QRhiSwapChain::NoVSync);
m_rp = m_sc->newCompatibleRenderPassDescriptor();
m_releasePool << m_rp;
m_sc->setRenderPassDescriptor(m_rp);
ensureSharedResources(m_rp);
}
void Window::releaseResources()
{
qDeleteAll(m_releasePool);
m_releasePool.clear();
delete m_sc;
m_sc = nullptr;
}
void Window::resizeSwapChain()
{
m_hasSwapChain = m_sc->buildOrResize();
const QSize outputSize = m_sc->currentPixelSize();
m_proj = r.r->clipSpaceCorrMatrix();
m_proj.perspective(45.0f, outputSize.width() / (float) outputSize.height(), 0.01f, 1000.0f);
m_proj.translate(0, 0, -4);
}
void Window::releaseSwapChain()
{
if (m_hasSwapChain) {
m_hasSwapChain = false;
m_sc->release();
}
}
void Window::render()
{
if (!m_hasSwapChain || m_notExposed)
return;
// If the window got resized or got newly exposed, resize the swapchain.
// (the newly-exposed case is not actually required by some
// platforms/backends, but f.ex. Vulkan on Windows seems to need it)
if (m_sc->currentPixelSize() != m_sc->surfacePixelSize() || m_newlyExposed) {
resizeSwapChain();
if (!m_hasSwapChain)
return;
m_newlyExposed = false;
}
QRhi::FrameOpResult result = r.r->beginFrame(m_sc);
if (result == QRhi::FrameOpSwapChainOutOfDate) {
resizeSwapChain();
if (!m_hasSwapChain)
return;
result = r.r->beginFrame(m_sc);
}
if (result != QRhi::FrameOpSuccess) {
requestUpdate();
return;
}
QRhiCommandBuffer *cb = m_sc->currentFrameCommandBuffer();
const QSize outputSizeInPixels = m_sc->currentPixelSize();
QRhiResourceUpdateBatch *u = r.r->nextResourceUpdateBatch();
if (d.initialUpdates) {
u->merge(d.initialUpdates);
d.initialUpdates->release();
d.initialUpdates = nullptr;
}
m_rotation += 1.0f;
QMatrix4x4 mvp = m_proj;
mvp.rotate(m_rotation, m_rotationAxis == 0 ? 1 : 0, m_rotationAxis == 1 ? 1 : 0, m_rotationAxis == 2 ? 1 : 0);
u->updateDynamicBuffer(d.ubuf, 0, 64, mvp.constData());
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);
}
u->updateDynamicBuffer(d.ubuf, 64, 4, &m_opacity);
cb->beginPass(m_sc->currentFrameRenderTarget(),
QColor::fromRgbF(float(m_bgColor.redF()), float(m_bgColor.greenF()), float(m_bgColor.blueF()), 1.0f),
{ 1.0f, 0 },
u);
cb->setGraphicsPipeline(d.ps);
cb->setViewport({ 0, 0, float(outputSizeInPixels.width()), float(outputSizeInPixels.height()) });
cb->setShaderResources();
const QRhiCommandBuffer::VertexInput vbufBinding(d.vbuf, 0);
cb->setVertexInput(0, 1, &vbufBinding);
cb->draw(3);
cb->endPass();
r.r->endFrame(m_sc);
requestUpdate();
}
void createWindow(bool noVSync)
{
static QColor colors[] = { Qt::red, Qt::green, Qt::blue, Qt::yellow, Qt::cyan, Qt::gray };
const int n = d.windows.count();
d.windows.append(new Window(QString::asprintf("Window #%d%s", n, noVSync ? " (no vsync)" : ""), colors[n % 6], n % 3, noVSync));
d.windows.last()->show();
}
void closeWindow()
{
delete d.windows.takeLast();
}
int main(int argc, char **argv)
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QApplication app(argc, argv);
#if defined(Q_OS_WIN)
graphicsApi = D3D11;
#elif defined(Q_OS_DARWIN)
graphicsApi = Metal;
#elif QT_CONFIG(vulkan)
graphicsApi = Vulkan;
#else
graphicsApi = OpenGL;
#endif
QCommandLineParser cmdLineParser;
cmdLineParser.addHelpOption();
QCommandLineOption glOption({ "g", "opengl" }, QLatin1String("OpenGL (2.x)"));
cmdLineParser.addOption(glOption);
QCommandLineOption vkOption({ "v", "vulkan" }, QLatin1String("Vulkan"));
cmdLineParser.addOption(vkOption);
QCommandLineOption d3dOption({ "d", "d3d11" }, QLatin1String("Direct3D 11"));
cmdLineParser.addOption(d3dOption);
QCommandLineOption mtlOption({ "m", "metal" }, QLatin1String("Metal"));
cmdLineParser.addOption(mtlOption);
cmdLineParser.process(app);
if (cmdLineParser.isSet(glOption))
graphicsApi = OpenGL;
if (cmdLineParser.isSet(vkOption))
graphicsApi = Vulkan;
if (cmdLineParser.isSet(d3dOption))
graphicsApi = D3D11;
if (cmdLineParser.isSet(mtlOption))
graphicsApi = Metal;
qDebug("Selected graphics API is %s", qPrintable(graphicsApiName()));
qDebug("This is a multi-api example, use command line arguments to override:\n%s", qPrintable(cmdLineParser.helpText()));
#if QT_CONFIG(vulkan)
r.instance = new QVulkanInstance;
if (graphicsApi == Vulkan) {
#ifndef Q_OS_ANDROID
r.instance->setLayers({ "VK_LAYER_LUNARG_standard_validation" });
#else
r.instance->setLayers(QByteArrayList()
<< "VK_LAYER_GOOGLE_threading"
<< "VK_LAYER_LUNARG_parameter_validation"
<< "VK_LAYER_LUNARG_object_tracker"
<< "VK_LAYER_LUNARG_core_validation"
<< "VK_LAYER_LUNARG_image"
<< "VK_LAYER_LUNARG_swapchain"
<< "VK_LAYER_GOOGLE_unique_objects");
#endif
if (!r.instance->create()) {
qWarning("Failed to create Vulkan instance, switching to OpenGL");
graphicsApi = OpenGL;
}
}
#endif
createRhi();
int winCount = 0;
QWidget w;
w.resize(800, 600);
w.setWindowTitle(QCoreApplication::applicationName() + QLatin1String(" - ") + graphicsApiName());
QVBoxLayout *layout = new QVBoxLayout(&w);
QPlainTextEdit *info = new QPlainTextEdit(
QLatin1String("This application tests rendering with the same QRhi instance (and so the same Vulkan/Metal/D3D device or OpenGL context) "
"to multiple windows via multiple QRhiSwapChain objects, from the same one thread. Some resources are shared across all windows.\n"
"\nNote that the behavior may differ depending on the underlying graphics API implementation and the number of windows. "
"One challenge here is the vsync throttling: with the default vsync/fifo presentation mode the behavior may differ between "
"platforms, drivers, and APIs as we present different swapchains' images in a row on the same thread. As a potential solution, "
"setting NoVSync on the second, third, and later window swapchains is offered as an option.\n"
"\n\nUsing API: ") + graphicsApiName());
info->setReadOnly(true);
layout->addWidget(info);
QLabel *label = new QLabel(QLatin1String("Window count: 0"));
layout->addWidget(label);
QCheckBox *vsCb = new QCheckBox(QLatin1String("Set NoVSync on all swapchains except the first"));
vsCb->setChecked(false);
layout->addWidget(vsCb);
QPushButton *btn = new QPushButton(QLatin1String("New window"));
QObject::connect(btn, &QPushButton::clicked, btn, [label, vsCb, &winCount] {
winCount += 1;
label->setText(QString::asprintf("Window count: %d", winCount));
const bool noVSync = vsCb->isChecked() && winCount > 1;
createWindow(noVSync);
});
layout->addWidget(btn);
btn = new QPushButton(QLatin1String("Close window"));
QObject::connect(btn, &QPushButton::clicked, btn, [label, &winCount] {
if (winCount > 0) {
winCount -= 1;
label->setText(QString::asprintf("Window count: %d", winCount));
closeWindow();
}
});
layout->addWidget(btn);
w.show();
int result = app.exec();
qDeleteAll(d.windows);
destroySharedResources();
destroyRhi();
#if QT_CONFIG(vulkan)
delete r.instance;
#endif
return result;
}