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// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include <QtTest/qtest.h>
#include <QtCore/qrandom.h>
#include <QtCore/qrect.h>
#include <QtQuick/private/qsgareaallocator_p.h>
class tst_QSGAreaAllocator : public QObject
{
Q_OBJECT
private slots:
void allocationsStayWithinSlice_data();
void allocationsStayWithinSlice();
void allocationsStayWithinSliceAfterDeallocation();
private:
static void verifyAllocations(const QList<QRect> &allocations, const QSize &size, int sliceHeight);
};
void tst_QSGAreaAllocator::verifyAllocations(const QList<QRect> &allocations,
const QSize &size,
int sliceHeight)
{
const QRect bounds(QPoint(0, 0), size);
for (qsizetype i = 0; i < allocations.size(); ++i) {
const QRect &rect = allocations.at(i);
QVERIFY2(bounds.contains(rect),
qPrintable(QStringLiteral("Allocation %1 is out of bounds").arg(i)));
QVERIFY2(rect.top() / sliceHeight == rect.bottom() / sliceHeight,
qPrintable(QStringLiteral("Allocation %1 (y=%2, height=%3) crosses slice boundary")
.arg(i).arg(rect.y()).arg(rect.height())));
for (qsizetype j = 0; j < i; ++j) {
QVERIFY2(!rect.intersects(allocations.at(j)),
qPrintable(QStringLiteral("Allocations %1 and %2 overlap").arg(i).arg(j)));
}
}
}
void tst_QSGAreaAllocator::allocationsStayWithinSlice_data()
{
QTest::addColumn<QSize>("size");
QTest::addColumn<int>("sliceHeight");
QTest::addColumn<QList<QSize>>("requests");
QTest::addColumn<QList<QPoint>>("expectedPositions");
// Full-width rows: the fourth row does not fit at the bottom of the first slice
// and has to be moved to the start of the second one.
QTest::newRow("rows")
<< QSize(64, 192) << 64
<< QList<QSize>{ QSize(64, 20), QSize(64, 20), QSize(64, 20), QSize(64, 20) }
<< QList<QPoint>{ QPoint(0, 0), QPoint(0, 20), QPoint(0, 40), QPoint(0, 64) };
// Allocation which exactly fills the first slice, followed by one which has
// to start at the next slice.
QTest::newRow("exactFit")
<< QSize(64, 128) << 64
<< QList<QSize>{ QSize(64, 64), QSize(64, 10) }
<< QList<QPoint>{ QPoint(0, 0), QPoint(0, 64) };
// A single allocation which is taller than what remains of the first slice
QTest::newRow("tallAfterShort")
<< QSize(64, 128) << 64
<< QList<QSize>{ QSize(64, 50), QSize(64, 30) }
<< QList<QPoint>{ QPoint(0, 0), QPoint(0, 64) };
}
void tst_QSGAreaAllocator::allocationsStayWithinSlice()
{
QFETCH(QSize, size);
QFETCH(int, sliceHeight);
QFETCH(QList<QSize>, requests);
QFETCH(QList<QPoint>, expectedPositions);
QSGAreaAllocator allocator(size, sliceHeight);
QList<QRect> allocations;
for (const QSize &request : std::as_const(requests)) {
const QRect rect = allocator.allocate(request);
QVERIFY(rect.isValid());
QCOMPARE(rect.size(), request);
allocations.append(rect);
}
verifyAllocations(allocations, size, sliceHeight);
if (QTest::currentTestFailed())
return;
for (qsizetype i = 0; i < allocations.size(); ++i)
QCOMPARE(allocations.at(i).topLeft(), expectedPositions.at(i));
}
void tst_QSGAreaAllocator::allocationsStayWithinSliceAfterDeallocation()
{
const QSize size(256, 256 * 4);
const int sliceHeight = 256;
QSGAreaAllocator allocator(size, sliceHeight);
QRandomGenerator rng(0x51ce);
// Fill the allocator with randomly sized rects
QList<QRect> allocations;
for (int i = 0; i < 1000; ++i) {
const QSize request(rng.bounded(4, 48), rng.bounded(4, 48));
const QRect rect = allocator.allocate(request);
if (rect.isValid())
allocations.append(rect);
}
QVERIFY(!allocations.isEmpty());
verifyAllocations(allocations, size, sliceHeight);
if (QTest::currentTestFailed())
return;
// Free every other allocation, so that free nodes are merged, and allocate again
QList<QRect> remaining;
for (qsizetype i = 0; i < allocations.size(); ++i) {
if (i % 2 == 0)
QVERIFY(allocator.deallocate(allocations.at(i)));
else
remaining.append(allocations.at(i));
}
for (int i = 0; i < 1000; ++i) {
const QSize request(rng.bounded(4, 64), rng.bounded(4, 64));
const QRect rect = allocator.allocate(request);
if (rect.isValid())
remaining.append(rect);
}
verifyAllocations(remaining, size, sliceHeight);
}
QTEST_APPLESS_MAIN(tst_QSGAreaAllocator)
#include "tst_qsgareaallocator.moc"