From 22e031135ac2b81d8ac5d8d17d5a5a5b40281b6d Mon Sep 17 00:00:00 2001 From: John Emmas Date: Sat, 28 May 2016 19:07:22 +0100 Subject: Emulate 'log1p()' and 'expm1()' using 'log()' and 'exp()' (for MSVC which didn't implement those functions until very recent versions). --- libs/pbd/msvc/msvc_pbd.cc | 42 ++++++++++++++++++++++++++++++++++++++++++ libs/pbd/pbd/msvc_pbd.h | 10 +++++++++- 2 files changed, 51 insertions(+), 1 deletion(-) (limited to 'libs') diff --git a/libs/pbd/msvc/msvc_pbd.cc b/libs/pbd/msvc/msvc_pbd.cc index ab79d8f45d..f49ac5393c 100644 --- a/libs/pbd/msvc/msvc_pbd.cc +++ b/libs/pbd/msvc/msvc_pbd.cc @@ -262,6 +262,47 @@ trunc(double x) return (floor(x)); } +#if defined(_MSC_VER) && (_MSC_VER < 1800) +//*************************************************************** +// +// expm1() +// +// Emulates C99 expm1() using exp(). +// +// Returns: +// +// On Success: (('e' raised to the power of 'x') - 1) +// (e.g. expm1(1) == 1.7182818). +// On Failure: None, except that calling exp(x) should generate +// an appropriate error for us (such as INF etc). +// +LIBPBD_API double PBD_APICALLTYPE +expm1(double x) +{ + return (exp(x) - (double)1.0); +} + +//*************************************************************** +// +// log1p() +// +// Emulates C99 log1p() using log(). +// +// Returns: +// +// On Success: The natural logarithm of (1 + x) +// (e.g. log1p(1) == 0.69314718). +// On Failure: None, except that calling log(x) should generate +// an appropriate error for us (such as ERANGE etc). +// +LIBPBD_API double PBD_APICALLTYPE +log1p(double x) +{ + return (log(x + (double)1.0)); +} +#endif + +#if defined(_MSC_VER) && (_MSC_VER < 1900) //*************************************************************** // // log2() @@ -280,6 +321,7 @@ log2(double x) { return (log(x) / log((double)2.0)); } +#endif namespace PBD { diff --git a/libs/pbd/pbd/msvc_pbd.h b/libs/pbd/pbd/msvc_pbd.h index 7529619f1d..5a6b550242 100644 --- a/libs/pbd/pbd/msvc_pbd.h +++ b/libs/pbd/pbd/msvc_pbd.h @@ -232,7 +232,15 @@ LIBPBD_API ssize_t PBD_APICALLTYPE pwrite(int handle, const void *buf, size_t LIBPBD_API int PBD_APICALLTYPE poll(struct pollfd *fds, nfds_t nfds, int timeout); LIBPBD_API double PBD_APICALLTYPE round(double x); LIBPBD_API double PBD_APICALLTYPE trunc(double x); -LIBPBD_API double PBD_APICALLTYPE log2(double x); + +#if defined(_MSC_VER) && (_MSC_VER < 1800) +LIBPBD_API double PBD_APICALLTYPE expm1(double x); +LIBPBD_API double PBD_APICALLTYPE log1p(double x); +#endif + +#if defined(_MSC_VER) && (_MSC_VER < 1900) +LIBPBD_API double PBD_APICALLTYPE log2 (double x); +#endif namespace PBD { -- cgit v1.2.3