diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/pj_math.c | 28 | ||||
| -rw-r--r-- | src/proj_math.h | 1 |
2 files changed, 29 insertions, 0 deletions
diff --git a/src/pj_math.c b/src/pj_math.c index 751c2750..97d4ae56 100644 --- a/src/pj_math.c +++ b/src/pj_math.c @@ -67,5 +67,33 @@ int pj_isnan (double x) { return x != x; } +double pj_round(double x) { + /* The handling of corner cases is copied from boost; see + * https://github.com/boostorg/math/pull/8 + * with improvements to return -0.0 when appropriate */ + double t; + if (x == 0) + return x; /* Retain sign of 0 */ + else if (0 < x && x < 0.5) + return +0.0; + else if (0 > x && x > -0.5) + return -0.0; + else if (x > 0) { + t = ceil(x); + return 0.5 < t - x ? t - 1 : t; + } else { /* Includes NaN */ + t = floor(x); + return 0.5 < x - t ? t + 1 : t; + } +} + +long pj_lround(double x) { + /* Default value for overflow + NaN + (x == LONG_MIN) */ + long r = LONG_MIN; + x = round(x); + if (fabs(x) < -(double)LONG_MIN) /* Assume (double)LONG_MIN is exact */ + r = (int)x; + return r; +} #endif /* !(defined(HAVE_C99_MATH) && HAVE_C99_MATH) */ diff --git a/src/proj_math.h b/src/proj_math.h index 1e0c6217..ca3ab401 100644 --- a/src/proj_math.h +++ b/src/proj_math.h @@ -29,6 +29,7 @@ #define PROJ_MATH_H #include <math.h> +#include <limits.h> #ifdef __cplusplus extern "C" { |