mesh.cpp Example File

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  #include "mesh.h"
  #include <QtConcurrentRun>
  #include <QFile>

  void Mesh::load(const QString &fn)
  {
      reset();
      m_maybeRunning = true;
      m_future = QtConcurrent::run([fn]() {
          MeshData md;
          QFile f(fn);
          if (!f.open(QIODevice::ReadOnly)) {
              qWarning("Failed to open %s", qPrintable(fn));
              return md;
          }
          QByteArray buf = f.readAll();
          const char *p = buf.constData();
          quint32 format;
          memcpy(&format, p, 4);
          if (format != 1) {
              qWarning("Invalid format in %s", qPrintable(fn));
              return md;
          }
          int ofs = 4;
          memcpy(&md.vertexCount, p + ofs, 4);
          ofs += 4;
          memcpy(md.aabb, p + ofs, 6 * 4);
          ofs += 6 * 4;
          const int byteCount = md.vertexCount * 8 * 4;
          md.geom.resize(byteCount);
          memcpy(md.geom.data(), p + ofs, byteCount);
          return md;
      });
  }

  MeshData *Mesh::data()
  {
      if (m_maybeRunning && !m_data.isValid())
          m_data = m_future.result();

      return &m_data;
  }

  void Mesh::reset()
  {
      *data() = MeshData();
      m_maybeRunning = false;
  }