ReadUInt32
if (!fStream->ReadUInt32(length)) {
if (!fStream->ReadUInt32(attr.val.uint32)) return NULL;
if (!fStream->ReadUInt32(attr.val.UInt32_XY.x) || !fStream->ReadUInt32(attr.val.UInt32_XY.y)) return NULL;
if (!fStream->ReadUInt32(attr.val.UInt32_BOX.x1) || !fStream->ReadUInt32(attr.val.UInt32_BOX.y1) ||
!fStream->ReadUInt32(attr.val.UInt32_BOX.x2) || !fStream->ReadUInt32(attr.val.UInt32_BOX.y2)) return NULL;
bool ReadUInt32(uint32& v);