问性能提升C++

EN

Point3* LASReader::GetPoint(int index)
{
    if (m_index == m_header.NPointRecords)
        return 0;

stream.seekg(GetOffset(index));
m_index++;

LASPOINTF1 p0;
LASPOINTF1 p1;
LASPOINTF2 p2;
LASPOINTF3 p3;
LASPOINTF4 p4;
LASPOINTF5 p5;
Vector3 position;

// Get the point values
switch (m_header.PointDataFormat)
{
case 0:
    stream.read((char *)&p0, sizeof(LASPOINTF0));
    position = Vector3(p0.X, p0.Y, p0.Z);
    break;
case 1:
    stream.read((char *)&p1, sizeof(LASPOINTF1));
    position = Vector3(p1.X, p1.Y, p1.Z);
    break;
case 2:
    stream.read((char *)&p2, sizeof(LASPOINTF2));
    position = Vector3(p2.X, p2.Y, p2.Z);
    break;
case 3:
    stream.read((char *)&p3, sizeof(LASPOINTF3));
    position = Vector3(p3.X, p3.Y, p3.Z);
    break;
case 4:
    stream.read((char *)&p4, sizeof(LASPOINTF4));
    position = Vector3(p4.X, p4.Y, p4.Z);
    break;
case 5:
    stream.read((char *)&p5, sizeof(LASPOINTF5));
    position = Vector3(p5.X, p5.Y, p5.Z);
    break;
}


// Calculate the real coordinates of the point
position = position * *m_scale + *m_offset;

return new Point3(position.GetX(), position.GetY(), position.GetZ());
}

// Main

int main()
{
    VertexPosColF* pcmVertices = new VertexPosColF[reader->GetHeader().NPointRecords];
    while (!reader->AllPointsRead())
{
    pcmVertices[i].Position = reader->GetPoint()->GetPosition()->GetD3DXVECTOR3();
    pcmVertices[i].Color = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);
    i++;
}
}