#include <QPainter>
  #include <opencv2/imgproc/imgproc.hpp>
  
  #include "DiffHistoGraph.h"
  
  DiffHistoGraph::DiffHistoGraph(QColor color, bool minusY, int scale, int width, int height, QWidget *parent)
    : QWidget(parent),
      m_minusY(minusY),
      m_color(color)
  {
    setFixedSize(width, height);
    m_scale = scale / 8.0;
  
    if (minusY)
      m_height = height / 2;
    else
      m_height = 0;
  }
  
  ///////////
  // slots //
  ///////////
  
  void DiffHistoGraph::setScale(int scale)
  {
    m_scale = scale / 8.0;
  }
  
  void DiffHistoGraph::appendDist(qreal dist)
  {
    m_distList.append(dist);
  
    if (m_distList.size() > width())
      m_distList.removeFirst();
  
    update();
  }
  
  void DiffHistoGraph::paintEvent(QPaintEvent *event)
  {
    Q_UNUSED(event);
    QPainter painter(this);
  
    // fill monitors background and set pen
    painter.fillRect(0, 0, width(), height(), QBrush(Qt::white));
    
    if (m_minusY) {
      painter.setPen(Qt::gray);
      painter.drawLine(0, m_height, width(), m_height);
    }
  
    int listSize = m_distList.size();
  
    painter.setPen(m_color);
  
    for (int i = 1; i < listSize; i++)
      painter.drawLine(i-1, height() * (1 - m_scale * m_distList[i-1]) - m_height, i, height() * (1 - m_scale * m_distList[i]) - m_height);
  }