StaggeredPixels: simplify isWithinMatrix

 * This is quite easy for rectangular pixels and matrices.

 */

bool StaggeredPixelDetectorModel::isWithinMatrix(const ROOT::Math::XYZPoint& position) const {

    // Check if we have an odd or even row

    bool odd_row = (static_cast<int>(std::lround(position.y() / pixel_size_.y())) % 2) != 0;

    // For odd rows, shift everything by the offset (positive or negative)

    if(position.x() < (-0.5 + (odd_row ? offset_ : 0.)) * pixel_size_.x() ||

       position.x() > (number_of_pixels_.x() - 0.5 + (odd_row ? offset_ : 0.)) * pixel_size_.x()) {

        return false;

    }

    if(position.y() < -0.5 * pixel_size_.y() || position.y() > (number_of_pixels_.y() - 0.5) * pixel_size_.y()) {

        return false;

    }

    return true;

    // Get indices of this pixel:

    const auto indices = getPixelIndex(position);

    // Check if indices are valid:

    return PixelDetectorModel::isWithinMatrix(indices.first, indices.second);

}

ROOT::Math::XYZPoint StaggeredPixelDetectorModel::getPixelCenter(const int x, const int y) const {