This approach allows us to maintain compatibility with the minimum supported CMake version 3.5,
while suppressing all policy warnings up to the latest version 3.31.
Fixed this deprecation warning:
``
CMake Deprecation Warning at CMakeLists.txt:1 (CMAKE_MINIMUM_REQUIRED):
Compatibility with CMake < 3.5 will be removed from a future version of CMake.
``
This can happen when mtllib is absent, points to a non-existing file, or
material names are incorrect. In either case it helps the reader
differentiate between materials that are actually specified in the file,
even if their definition happens to match the default, from materials
that were never loaded in the first place.
Some .obj files have extra whitespace after usemtl and other statements;
this may interfere with parsing, for example by adding a space to the
material name which can result in inability to find it in .mtl file.
For consistency, we replace all uses of is_end_of_name with skip_name
that handles this by leaving trailing whitespace alone. It will be
skipped in the parsing flow when we skip the newline, which is similar
to the behavior of trailing whitespace after numeric data (which
parse_float/int leave alone).
When an array reached a size that would require >4GB allocation, the
argument to realloc would overflow during multiplication, resulting in a
very small allocation and a subsequent out of bounds access.
This change fixes that and also adjusts capacity calculation so that it
doesn't overflow 32-bit range until it's basically impossible not to.
This is not perfect - in particular, on 32-bit systems there's a risk of
size_t overflow that remains, however because we grow in 1.5x
increments, realistically an attempt to grow a 2GB allocation to the
next increment would fail before that. We can also technically overflow
capacity even after the adjustment, but that requires 3+B elements which
effectively means an .obj file on the scale of hundreds of gigabytes, at
which point maybe a streaming parser would be more practical.
In some cases we need to know the length of `indices`.
Currently need to calculate the sum of the `face_vertices`
elements to get this value.
It would be convenient if we could get the value directly.
On Windows, paths with mixed slashes weren't processed correctly as `\`
would be picked if it was anywhere in the path for the purpose of
determining base.
This also removes the #ifdef _WIN32 from the logic; this helps on
platforms like Emscripten where running the resulting binary that
wasn't compiled with WIN32 still needs backslash processing; paths with
backslashes on Linux should be exceedingly rare, plus we *already*
correct backslashes with forward slashes on Linux anyway...
Problem: I read a bare OBJ so no MTL is provided. I still want
to keep the materials setup across the scene for further edit.
Fix: Instead of using a fallback material (idx 0), create a material
for each not-defined material while keeping the name
so that the structure of the model is conserved.
