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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "beziercurve.h"
#include <QtQuick/qsgnode.h>
#include <QtQuick/qsgflatcolormaterial.h>
//! [1]
BezierCurve::BezierCurve(QQuickItem *parent)
: QQuickItem(parent)
, m_p1(0, 0)
, m_p2(1, 0)
, m_p3(0, 1)
, m_p4(1, 1)
, m_segmentCount(32)
{
setFlag(ItemHasContents, true);
}
//! [1]
//! [2]
BezierCurve::~BezierCurve() = default;
//! [2]
//! [3]
void BezierCurve::setP1(const QPointF &p)
{
if (p == m_p1)
return;
m_p1 = p;
emit p1Changed(p);
update();
}
//! [3]
void BezierCurve::setP2(const QPointF &p)
{
if (p == m_p2)
return;
m_p2 = p;
emit p2Changed(p);
update();
}
void BezierCurve::setP3(const QPointF &p)
{
if (p == m_p3)
return;
m_p3 = p;
emit p3Changed(p);
update();
}
void BezierCurve::setP4(const QPointF &p)
{
if (p == m_p4)
return;
m_p4 = p;
emit p4Changed(p);
update();
}
void BezierCurve::setSegmentCount(int count)
{
if (m_segmentCount == count)
return;
m_segmentCount = count;
emit segmentCountChanged(count);
update();
}
//! [4]
QSGNode *BezierCurve::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
QSGGeometryNode *node = nullptr;
QSGGeometry *geometry = nullptr;
if (!oldNode) {
node = new QSGGeometryNode;
//! [4] //! [5]
geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), m_segmentCount);
geometry->setLineWidth(2);
geometry->setDrawingMode(QSGGeometry::DrawLineStrip);
node->setGeometry(geometry);
node->setFlag(QSGNode::OwnsGeometry);
//! [5] //! [6]
auto *material = new QSGFlatColorMaterial;
material->setColor(QColor(255, 0, 0));
node->setMaterial(material);
node->setFlag(QSGNode::OwnsMaterial);
//! [6] //! [7]
} else {
node = static_cast<QSGGeometryNode *>(oldNode);
geometry = node->geometry();
geometry->allocate(m_segmentCount);
}
//! [7]
//! [8]
QSizeF itemSize = size();
QSGGeometry::Point2D *vertices = geometry->vertexDataAsPoint2D();
for (int i = 0; i < m_segmentCount; ++i) {
qreal t = i / qreal(m_segmentCount - 1);
qreal invt = 1 - t;
QPointF pos = invt * invt * invt * m_p1
+ 3 * invt * invt * t * m_p2
+ 3 * invt * t * t * m_p3
+ t * t * t * m_p4;
float x = pos.x() * itemSize.width();
float y = pos.y() * itemSize.height();
vertices[i].set(x, y);
}
node->markDirty(QSGNode::DirtyGeometry);
//! [8]
//! [9]
return node;
}
//! [9]
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