Method paintMap

app/src/UI/Widgets/GPS.cpp:755–807

* @brief Renders the visible portion of the map using cached tiles. */

 * @brief Renders the visible portion of the map using cached tiles.
 */
void Widgets::GPS::paintMap(QPainter* painter, const QSize& view)
{
  if (!painter) {
    qWarning() << "GPS::paintMap: null painter";
    return;
  }

  painter->setRenderHint(QPainter::Antialiasing, false);
  painter->setRenderHint(QPainter::SmoothPixmapTransform, true);
  painter->fillRect(painter->viewport(), QColor(0x0C, 0x47, 0x5C));

  const int baseZoom          = qFloor(m_zoom);
  const double fractionalZoom = m_zoom - baseZoom;
  const double scale          = qPow(2.0, fractionalZoom);
  const int tileSize          = 256;
  const double scaledTileSize = tileSize * scale;

  const QPointF centerTileBase = m_centerTile / scale;
  const int centerX            = static_cast<int>(centerTileBase.x());
  const int centerY            = static_cast<int>(centerTileBase.y());

  const int offsetX = qRound((centerTileBase.x() - centerX) * scaledTileSize);
  const int offsetY = qRound((centerTileBase.y() - centerY) * scaledTileSize);

  const int tilesX = qCeil(view.width() / scaledTileSize) + 1;
  const int tilesY = qCeil(view.height() / scaledTileSize) + 1;

  for (int dx = -tilesX / 2; dx <= tilesX / 2; ++dx) {
    for (int dy = -tilesY / 2; dy <= tilesY / 2; ++dy) {
      const int tx        = centerX + dx;
      const int ty        = centerY + dy;
      const int wrappedTx = (tx % (1 << baseZoom) + (1 << baseZoom)) % (1 << baseZoom);

      if (ty < 0 || ty >= (1 << baseZoom))
        continue;

      const QString url = tileUrl(wrappedTx, ty, baseZoom);
      const int drawX   = view.width() / 2 + qRound(dx * scaledTileSize) - offsetX;
      const int drawY   = view.height() / 2 + qRound(dy * scaledTileSize) - offsetY;
      const QRect targetRect(drawX, drawY, qRound(scaledTileSize), qRound(scaledTileSize));

      if (s_tileCache.contains(url))
        painter->drawImage(targetRect, *s_tileCache.object(url));

      else
        renderFallbackTile(painter, tx, ty, baseZoom, targetRect, scaledTileSize);

      renderCloudOverlay(painter, wrappedTx, ty, baseZoom, targetRect, scaledTileSize);
      renderWeatherOverlay(painter, wrappedTx, ty, baseZoom, targetRect);
      renderReferenceOverlay(painter, wrappedTx, ty, baseZoom, targetRect);
    }
  }
}

/**
 * @brief Overlays the equirectangular cloud image onto the given tile rect.