Method renderGrid

app/src/UI/Widgets/Plot3D.cpp:906–956

* @brief Renders the infinite grid overlay as a 2D pixmap. */

 * @brief Renders the infinite grid overlay as a 2D pixmap.
 */
QImage Widgets::Plot3D::renderGrid(const QMatrix4x4& matrix)
{
  QImage img(widgetSize(), QImage::Format_ARGB32_Premultiplied);
  img.setDevicePixelRatio(qApp->devicePixelRatio());
  img.fill(Qt::transparent);

  QPainter painter(&img);
  painter.setRenderHint(QPainter::Antialiasing, true);

  const double numSteps = 10;
  const double step     = gridStep();
  const double l        = numSteps * step;
  const float cx        = std::round(m_centerPoint.x() / step) * step;
  const float cy        = std::round(m_centerPoint.y() / step) * step;

  QVector<QPair<QVector3D, QVector3D>> gridLines;
  for (int i = -numSteps; i <= numSteps; ++i) {
    if (i == 0)
      continue;

    float x       = cx + i * step;
    float y       = cy + i * step;
    const auto x1 = QVector3D(x, cy + l, 0);
    const auto x2 = QVector3D(x, cy - l, 0);
    const auto y1 = QVector3D(cx + l, y, 0);
    const auto y2 = QVector3D(cx - l, y, 0);

    gridLines.append({x1, x2});
    gridLines.append({y1, y2});
  }

  const float ax                    = m_centerPoint.x();
  const float ay                    = m_centerPoint.y();
  QPair<QVector3D, QVector3D> xAxis = {QVector3D(ax - l, ay, 0), QVector3D(ax + l, ay, 0)};
  QPair<QVector3D, QVector3D> yAxis = {QVector3D(ax, ay - l, 0), QVector3D(ax, ay + l, 0)};

  auto color = m_gridMinorColor;
  color.setAlpha(100);
  for (const auto& line : gridLines)
    drawLine3D(painter, matrix, line.first, line.second, color, 1, Qt::DashLine);

  drawLine3D(painter, matrix, xAxis.first, xAxis.second, m_xAxisColor, 1.5, Qt::SolidLine);
  drawLine3D(painter, matrix, yAxis.first, yAxis.second, m_yAxisColor, 1.5, Qt::SolidLine);

  const QString stepLabel = tr("Grid Interval: %1 unit(s)").arg(step);
  painter.setPen(m_textColor);
  painter.setFont(Misc::CommonFonts::instance().monoFont());
  painter.drawText(QPoint(8, height() - 8), stepLabel);

  return img;
}

/**
 * @brief Renders the camera orientation indicator as a 2D pixmap.