With -jN, make started third-party and fftw targets in parallel.
libspecbleach depended on FFTW_HEADER which has no explicit rule
(it is a side effect of make install), causing 'No rule to make target'.
Object compilation also could start before FFTW headers were ready.
Fix: depend on FFTW_LIB_D (has an explicit rule) instead of FFTW_HEADER,
and add FFTW_LIB_D as order-only prerequisite for .o compilation.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
FFTW 3.3.11 has no pre-built Windows binaries, so Makefile.windows now
downloads the source tarball and cross-compiles it twice with MinGW-w64:
once for double precision and once for float (--enable-float), installing
both into third_party/fftw-win64/. Links with -lfftw3/-lfftw3f via
libtool-generated import libs instead of dlltool-generated ones.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Makefile.windows builds libwdsp.dll and libwdsp.a for 64-bit Windows
on Linux. FFTW 3.3.11 Windows binaries are downloaded automatically
from fftw.org and import libraries are generated with dlltool.
README updated with Windows build instructions and FFTW version bump.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
