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// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include <QTest>
#include <QtGui/qpainterpath.h>
#include <QtGui/qtransform.h>
#include <QtGui/private/qtriangulator_p.h>
static const qreal maxCoordinate = qreal((1 << 21) - 1) / 32;
class tst_QTriangulator : public QObject
{
Q_OBJECT
private slots:
void square();
void clampRect_data();
void clampRect();
void clampPolygon();
void clampWithTransform();
void clampCurve();
void clampPolyline();
};
static quint32 indexAt(const QVertexIndexVector &indices, int i)
{
if (indices.type() == QVertexIndexVector::UnsignedInt)
return static_cast<const quint32 *>(indices.data())[i];
return static_cast<const quint16 *>(indices.data())[i];
}
static bool verticesInRange(const QList<qreal> &vertices)
{
for (qreal v : vertices) {
if (!(qAbs(v) <= maxCoordinate)) // written this way to also catch NaN
return false;
}
return true;
}
static bool indicesInRange(const QVertexIndexVector &indices, int vertexCount)
{
for (int i = 0; i < indices.size(); ++i) {
quint32 index = indexAt(indices, i);
if (index >= quint32(vertexCount))
return false;
}
return true;
}
static qreal triangleSetArea(const QTriangleSet &set)
{
qreal area = 0.0;
for (int i = 0; i + 2 < set.indices.size(); i += 3) {
const quint32 a = indexAt(set.indices, i);
const quint32 b = indexAt(set.indices, i + 1);
const quint32 c = indexAt(set.indices, i + 2);
const qreal ax = set.vertices.at(2 * a), ay = set.vertices.at(2 * a + 1);
const qreal bx = set.vertices.at(2 * b), by = set.vertices.at(2 * b + 1);
const qreal cx = set.vertices.at(2 * c), cy = set.vertices.at(2 * c + 1);
area += qAbs((bx - ax) * (cy - ay) - (cx - ax) * (by - ay)) / 2;
}
return area;
}
void tst_QTriangulator::square()
{
QPainterPath path;
path.addRect(QRectF(0, 0, 64, 64));
const QTriangleSet set = qTriangulate(path);
QVERIFY(!set.vertices.isEmpty());
QCOMPARE(set.indices.size() % 3, 0);
QVERIFY(verticesInRange(set.vertices));
QVERIFY(indicesInRange(set.indices, set.vertices.size() / 2));
QCOMPARE(triangleSetArea(set), qreal(64 * 64));
}
void tst_QTriangulator::clampRect_data()
{
QTest::addColumn<QRectF>("rect");
QTest::newRow("just out of range") << QRectF(-70000, -70000, 140000, 140000);
QTest::newRow("large") << QRectF(1e6, 1e6, 1e6, 1e6);
QTest::newRow("huge") << QRectF(-1e12, -1e12, 2e12, 2e12);
QTest::newRow("extreme") << QRectF(1e30, 1e30, 1e30, 1e30);
QTest::newRow("negative extreme") << QRectF(-2e30, -2e30, 1e30, 1e30);
QTest::newRow("partially in range") << QRectF(-100, -100, 1e8, 1e8);
}
void tst_QTriangulator::clampRect()
{
QFETCH(QRectF, rect);
QPainterPath path;
path.addRect(rect);
// Out-of-range coordinates must be clamped instead of triggering
// asserts or integer overflow in the fixed point representation.
const QTriangleSet set = qTriangulate(path);
QVERIFY(verticesInRange(set.vertices));
QVERIFY(indicesInRange(set.indices, set.vertices.size() / 2));
}
void tst_QTriangulator::clampPolygon()
{
// The raw polygon overload performs no validation of its input, so pass
// extreme values directly.
const qreal polygon[] = {
-1e100, 0.0,
1e100, -1e100,
1e100, 1e100,
0.0, 65536.0,
};
const QTriangleSet set = qTriangulate(polygon, 4);
QVERIFY(verticesInRange(set.vertices));
QVERIFY(indicesInRange(set.indices, set.vertices.size() / 2));
}
void tst_QTriangulator::clampWithTransform()
{
// In-range path coordinates mapped out of range by the transform.
QPainterPath path;
path.addRect(QRectF(0, 0, 100, 100));
const QTriangleSet set = qTriangulate(path, QTransform::fromScale(1e7, 1e7));
QVERIFY(verticesInRange(set.vertices));
QVERIFY(indicesInRange(set.indices, set.vertices.size() / 2));
}
void tst_QTriangulator::clampCurve()
{
// Exercises the bezier flattening code path.
QPainterPath path;
path.moveTo(0, 0);
path.cubicTo(1e8, 0, 1e8, 1e8, 0, 1e8);
path.closeSubpath();
const QTriangleSet set = qTriangulate(path);
QVERIFY(verticesInRange(set.vertices));
QVERIFY(indicesInRange(set.indices, set.vertices.size() / 2));
}
void tst_QTriangulator::clampPolyline()
{
QPainterPath path;
path.moveTo(-1e8, -1e8);
path.lineTo(1e8, -1e8);
path.lineTo(1e8, 1e8);
path.lineTo(-1e8, 1e8);
path.closeSubpath();
const QPolylineSet set = qPolyline(path);
QVERIFY(verticesInRange(set.vertices));
}
QTEST_MAIN(tst_QTriangulator)
#include "tst_qtriangulator.moc"