[Auburn]

FastNoise_C.h uses bool as the return type of fnSetVariableFloat, fnSetVariableIntEnum, fnSetNodeLookup, fnSetHybridNodeLookup and fnSetHybridFloat, but never includes <stdbool.h>. A C file that includes the header fails to compile before C23:

FastNoise/FastNoise_C.h(415,15): error: unknown type name 'bool'

This adds #include <stdbool.h> after Utility/Export.h, inside #ifndef __cplusplus, so C++ consumers are unchanged.

Testing

A small .c file that includes only <FastNoise/FastNoise_C.h> (no stdbool.h of its own), builds a FractalFBm + Simplex tree from metadata, and calls all the bool setters plus fnGenUniformGrid2D / fnGenSingle2D:

• gcc 13.3 (WSL): -std=c99, c11, c17 and c2x with -Wall -Wextra -pedantic -Werror all compile. Against the master header it fails with the bool errors.
• clang-cl 19 /TC /W4 /WX: compiles, links against a Release FastNoise.dll and runs; setters return true on valid indices and false on an out-of-range one.
• FastNoiseCpp11Test and the DLL (which compiles FastNoise_C.cpp as C++) build and run as before.