Several places in the code call `std::vector<aiVector3D>.emplace_back(0, 0, 0)`. The constructor of `aiVector3D` actually expects arguments of the type `ai_real`, (alias of `float` if compiling without `ASSIMP_DOUBLE_PRECISION`) but the literal `0` is of type `int`.
`emplace_back()` does support promotion, but `int` to `float` is a potentially lossy conversion. tl;dr: On warning level 4, MSVC spits out a very deeply nested `warning C4244: 'argument': conversion from '_Ty' to 'TReal', possible loss of data with _Ty=int and TReal=ai_real`.
BaseImporter::SearchFileHeaderForToken() expected a pointer to a non-const token list. This was probably an oversight, as nobody would realistically expect the function to change the list. Furthermore, it prevented token lists from being compiled to read-only memory, in some cases even causing the compiler to generate thread-safe initialization.
The list is now const and all callers declare their token lists static const, thus compiling them to read-only memory.
The search for a matching importer had a few issues, see #3791. There were two different mechanisms to determine whether an importer accepts a specific file extension:
1. `aiImporterDesc::mFileExtensions`, which was forwarded to the UI via `BaseImporter::GetExtensionList()`.
2. `BaseImporter::CanRead()` when called with `checkSig == false`, which determines whether to actually use that importer.
Both were redundant and got out of sync repeatedly. I removed 2. completely and replaced it with 1., thereby syncing UI/import and shortening all `BaseImporter::CanRead()` implementations.
Further bugfixes:
- fixed glTF2 importer throwing exceptions when checking whether it can load a file
- removed `BaseImporter::SimpleExtensionCheck()` because it is no longer used and had a bug with case sensitivity
Since the `checkSig` parameter in `BaseImporter::CanRead()` is now useless, it can be removed completely. I’m not sure if this would break ABI compatiblity, so I’ll submit it with a later pull request.
std::string s(""); s = ""; calls the copy constructor, which in turn calls strlen(), … assigning a default-constructed string generates fewer instructions and is therefore preferred.
With C++11 uniform initialization, you’d simply write s = { } instead.
Kim Kulling
Krishty
Aaron Gokaslan
RedSkittleFox
Krishty
Malcolm Tyrrell