RowOrder.hpp

#pragma once
#include <QtGui/private/qrhi_p.h>
 
#include <QByteArray>
#include <QImage>
 
#include <cstring>
 
namespace score::gfx
{
inline bool uploadReversesRows(const QRhi& rhi) noexcept
{
  return rhi.isYUpInNDC();
}
 
inline void
copyRowsReversed(void* dst, const void* src, qsizetype rowBytes, int rows) noexcept
{
  auto* d = static_cast<char*>(dst);
  auto* s = static_cast<const char*>(src) + qsizetype(rows - 1) * rowBytes;
  for(int y = 0; y < rows; ++y, d += rowBytes, s -= rowBytes)
    std::memcpy(d, s, rowBytes);
}
 
inline QByteArray
bytesInPublishedRowOrder(const QRhi& rhi, QByteArray bytes, int rows)
{
  if(!uploadReversesRows(rhi) || rows <= 1 || bytes.size() % rows != 0)
    return bytes;
  QByteArray out(bytes.size(), Qt::Uninitialized);
  copyRowsReversed(out.data(), bytes.constData(), bytes.size() / rows, rows);
  return out;
}
 
inline QImage imageInPublishedRowOrder(const QRhi& rhi, QImage img)
{
  if(!uploadReversesRows(rhi) || img.height() <= 1)
    return img;
#if QT_VERSION >= QT_VERSION_CHECK(6, 9, 0)
  return std::move(img).flipped(Qt::Vertical);
#else
  return std::move(img).mirrored(false, true);
#endif
}
}