textureitem.h - mozsearch

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// Copyright (C) 2025 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

#ifndef TEXTUREITEM_H

#define TEXTUREITEM_H

#include <QQuickPaintedItem>

#include <QQuick3DTextureData>

#include <QImage>

class TextureItem : public QQuickPaintedItem {

    Q_OBJECT

    Q_PROPERTY(const QQuick3DTextureData* textureData READ textureData NOTIFY textureDataChanged FINAL)

    QML_ELEMENT

public:

    TextureItem(QQuickItem *parent = nullptr);

    void paint(QPainter *painter) override;

    const QQuick3DTextureData *textureData() const;

    Q_INVOKABLE void setPoint(float x, float y, int id, bool pressed);

    Q_INVOKABLE void setUv(float u, float v, int id, bool pressed);

    Q_INVOKABLE void clear(const QColor &color);

    Q_INVOKABLE void setColor(const QColor &newColor, int id = 0);

    Q_INVOKABLE void setPenWidth(qreal newPenWidth);

    Q_INVOKABLE void resetPoint(int id);

public slots:

    void updateImage();

signals:

    void textureDataChanged();

    void colorChanged();

    void penWidthChanged();

private:

    struct TouchPointState {

        QColor color = "red";

        qreal penWidth = 10; // unused

        double alpha = 0.5;  // smoothing factor (0..1)

        bool initialized = false;

        QPointF prevFiltered;

        QPointF prevRaw;

        qint64 prevTime = 0; // timestamp in milliseconds

        void reset() {

            initialized = false;

            prevTime = 0;

        QPointF filter(const QPointF &unfiltered, qint64 timestamp) {

            prevRaw = unfiltered;

            if (!initialized) {

                prevFiltered = unfiltered;

                prevTime = timestamp;

                initialized = true;

            } else {

                // Adjust alpha based on time delta

                qint64 dt = timestamp - prevTime;

                double adaptiveAlpha = qMin(1.0, alpha * (dt / 16.0)); // 16ms = ~60fps baseline

                prevFiltered.setX(adaptiveAlpha * unfiltered.x() + (1 - adaptiveAlpha) * prevFiltered.x());

                prevFiltered.setY(adaptiveAlpha * unfiltered.y() + (1 - adaptiveAlpha) * prevFiltered.y());

                prevTime = timestamp;

            return prevFiltered;

};

    void reset(TouchPointState &s);

    QHash<int, TouchPointState> state;

    QQuick3DTextureData m_textureData;

    QImage m_image;

    qreal m_penWidth = 10;

};

#endif // TEXTUREITEM_H