#include "waterwave.h"

waterwave::waterwave(QWidget *parent) : QWidget(parent)
{
    m_size = 100;
    m_offset = 0;
    m_waterDensity = 5;
    m_waterHeightRate = 0.03;
    m_max = 100;
    m_min = 0;
    m_value = 0;
    setFixedSize(QSize(m_size, m_size));
    startTimer(100);
}

void waterwave::setvalue(int value)
{
    if(m_value != value && value <= 100 && value >= 0) {
        m_value = value;
        this->update();
    }
}


void waterwave::paintEvent(QPaintEvent *event)
{
    //qDebug() << "paintEvent";
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    // 背景透明
    painter.save();
    QPen pen;
    pen.setColor(QColor(0, 0, 0, 0));
    painter.setPen(pen);
    painter.setBrush(QBrush(QColor(0, 0, 0, 0)));
    painter.drawRect(QRect(0, 0, m_size, m_size));
    painter.restore();
    // 绘制波纹
    QColor bgColor(Qt::white);
    QColor fillColor("#00BCD4");
    qreal percent = 1 - (m_value - m_min) / (m_max - m_min);
    //qDebug() << percent << m_offset;
    // 正弦曲线公式 y = A * sin(ωx + φ) + k
    // w 周期,水波的密度,同长度下水波的个数
    qreal w = m_waterDensity * M_PI / m_size;
    // A 振幅,水波波动的高度
    qreal A = m_size * m_waterHeightRate;
    // k y轴偏移,可以理解为进度宝粉币
    qreal k = m_size * percent;
    //第一条水波路径
    QPainterPath wavePath1;
    //第二条波水波路径
    QPainterPath wavePath2;
    //移动到左上角起始点
    wavePath1.moveTo(0, m_size);
    wavePath2.moveTo(0, m_size);
    m_offset += 0.6;
    if (m_offset > (m_size / 2)) {
        m_offset = 0;
    }
    for(int x = 0; x <= m_size; x++) {
        qreal waveY1 = (A * sin(w * x + m_offset)) + k;
        qreal waveY2 = (A * sin(w * x + m_offset + (m_size / 2 * w))) + k;
        //如果当前值为最小值则Y轴为高度
        if (m_value == m_min) {
            waveY1 = m_size;
            waveY2 = m_size;
        }
        //如果当前值为最大值则Y轴为0
        if (m_value == m_max) {
            waveY1 = 0;
            waveY2 = 0;
        }
        wavePath1.lineTo(x, waveY1);
        wavePath2.lineTo(x, waveY2);
    }
    // 方形加上水波纹
    wavePath1.lineTo(m_size, m_size);
    wavePath2.lineTo(m_size, m_size);
    // 圆形路径
    QPainterPath bigPath;
    bigPath.addEllipse(0, 0, m_size, m_size);
    painter.setBrush(bgColor);
    painter.save();
    QPainterPath path;
    painter.setPen(Qt::NoPen);
    QColor waterColor1 = fillColor;
    waterColor1.setAlpha(100);
    QColor waterColor2 = fillColor;
    waterColor2.setAlpha(180);
    // intersected 之后是波浪加上圆弧
    path = bigPath.intersected(wavePath1);
    painter.setBrush(waterColor1);
    painter.drawPath(path);
//    painter.drawPath(wavePath1);
//    painter.drawPath(wavePath2);
    path = bigPath.intersected(wavePath2);
    painter.setBrush(waterColor2);
    painter.drawPath(path);
    painter.restore();
    QFont font;
    font.setPixelSize(m_size / 5);
    painter.setPen(Qt::black);
    painter.setFont(font);
    painter.drawText(this->rect(), Qt::AlignCenter, QString("%0%").arg(QString::number(m_value)));
}


void waterwave::timerEvent(QTimerEvent *event)
{
    this->update();
}