Introduce a C-first TinyGLTF v3 runtime in tiny_gltf_v3.c with a pure-C JSON backend, hook the public header to the new implementation, and add CMake/test coverage for parse and write round-trips.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Replace strtod() with Clinger's fast path in tinygltf_json.h for ~1.5x
faster JSON float parsing. The new parser accumulates all digits into a
uint64 mantissa and uses exact power-of-10 tables for conversion,
avoiding locale-dependent strtod for ~99% of JSON float values.
Add optional float32 parse mode (parse_float32 option) that parses JSON
floats at single precision — fewer significant digits needed, wider fast
path range. Breaks strict double-precision conformance but sufficient
for glTF data which is typically single-precision.
Benchmark additions:
- gen_synthetic: add float_heavy preset (~500MB ASCII float JSON)
- bench_v3: add --float32 flag for float32 parse mode benchmarking
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
