A virtual POF ignored the load status of its base POF, so a base that
failed to load (missing, bad version, or rejected after parsing) was
still built upon and reported as a successful load. Likewise, every
operation that copies from another POF used it even if that POF had
failed to load.
Return FAIL from read_virtual_model_file when the base POF fails, and
have the operations skip, with a warning, any source POF that failed.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Several changes related to the volumetrics model fix:
1. Update the `model_load()` prototype with better parameter names, including a new `ErrorType` enum defined in pstypes.h
2. Update the `MIN`, `MAX`, and `CLAMP` macros, all of which were susceptible to performance issues because they duplicated their tokens. This could cause functions or calculations to be re-run unnecessarily. Since the codebase is now on C++17, `std::clamp()` can be used.
3. Update the rest of the codebase to fix any associated issues.
