M_PI is not standard C++. MSVC defines it only when _USE_MATH_DEFINES is set
before <cmath>, so the radial background kernel's azimuth loop does not compile
there:
error C2065: 'M_PI': undeclared identifier
error C2737: 'phi': const object must be initialized (cascade from the first)
GCC and Clang define it anyway, which is why the Linux build stayed green.
image_analysis is viewer-reachable, so it has to build under MSVC.
common/JFJochMath.h already carries a constexpr PI for exactly this reason - its
comment names this case - so use that. Same value to the last digit, so the
integration results are unchanged; the CPU/GPU parity test passes unaltered
(9002 assertions).
This was the only M_PI left in the viewer-reachable tree. The remaining uses are
in tests/, which Windows does not build (JFJOCH_VIEWER_ONLY is forced there).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
leonarski_fandClaude Opus 5
b71e8c6a56