diff options
| -rw-r--r-- | src/math.cpp | 138 | ||||
| -rw-r--r-- | src/proj_math.h | 21 |
2 files changed, 0 insertions, 159 deletions
diff --git a/src/math.cpp b/src/math.cpp index 6c1b6d1b..90d35001 100644 --- a/src/math.cpp +++ b/src/math.cpp @@ -41,141 +41,3 @@ int pj_isnan (double x) { /* cppcheck-suppress duplicateExpression */ return x != x; } - -#if !(defined(HAVE_C99_MATH) && HAVE_C99_MATH) - -/* Define C99 compatible versions of - * hypot - * log1p - * asinh - * atanh - * copysign - * cbrt - * remainder - * remquo - * round - * lround - */ - -/* Compute hypotenuse */ -double pj_hypot(double x, double y) { - x = fabs(x); - y = fabs(y); - if (x < y) { - x /= y; /* y is nonzero */ - return y * sqrt(1 + x * x); - } else { - y /= (x != 0 ? x : 1); - return x * sqrt(1 + y * y); - } -} - -/* Compute log(1+x) accurately */ -double pj_log1p(double x) { - volatile double - y = 1 + x, - z = y - 1; - /* Here's the explanation for this magic: y = 1 + z, exactly, and z - * approx x, thus log(y)/z (which is nearly constant near z = 0) returns - * a good approximation to the true log(1 + x)/x. The multiplication x * - * (log(y)/z) introduces little additional error. */ - return z == 0 ? x : x * log(y) / z; -} - -/* Compute asinh(x) accurately */ -double pj_asinh(double x) { - double y = fabs(x); /* Enforce odd parity */ - y = pj_log1p(y * (1 + y/(pj_hypot(1.0, y) + 1))); - return x > 0 ? y : (x < 0 ? -y : x); /* asinh(-0.0) = -0.0 */ -} - -/* Compute atanh(x) accurately */ -double pj_atanh(double x) { - double y = fabs(x); /* Enforce odd parity */ - y = pj_log1p(2 * y/(1 - y))/2; - return x > 0 ? y : (x < 0 ? -y : x); /* atanh(-0.0) = -0.0 */ -} - -/* Implement copysign(x, y) */ -double pj_copysign(double x, double y) { - /* 1/y trick to get the sign of -0.0 */ - return fabs(x) * (y < 0 || (y == 0 && 1/y < 0) ? -1 : 1); -} - -/* Implement cbrt(x) */ -double pj_cbrt(double x) { - double y = pow(fabs(x), 1/3.0); /* Return the real cube root */ - return x > 0 ? y : (x < 0 ? -y : x); /* cbrt(-0.0) = -0.0 */ -} - -/* Implement remainder(x, y) with ties to even */ -double pj_remainder(double x, double y) { - double z; - y = fabs(y); /* The result doesn't depend on the sign of y */ - z = fmod(x, y); - if (z == 0) - /* This shouldn't be necessary. However, before version 14 (2015), - * Visual Studio had problems dealing with -0.0. Specifically - * VC 10,11,12 and 32-bit compile: fmod(-0.0, 360.0) -> +0.0 - * python 2.7 on Windows 32-bit machines has the same problem. */ - z = pj_copysign(z, x); - else if (2 * fabs(z) == y) - z -= fmod(x, 2 * y) - z; /* Implement ties to even */ - else if (2 * fabs(z) > y) - z += (z < 0 ? y : -y); /* Fold remaining cases to (-y/2, y/2) */ - return z; -} - -/* Implement remquo(x, y, n) with n giving low 3 bits + sign of x/y */ -double pj_remquo(double x, double y, int* n) { - double z = pj_remainder(x, y); - if (n) { - double - a = pj_remainder(x, 2 * y), - b = pj_remainder(x, 4 * y), - c = pj_remainder(x, 8 * y); - *n = (a > z ? 1 : (a < z ? -1 : 0)); - *n += (b > a ? 2 : (b < a ? -2 : 0)); - *n += (c > b ? 4 : (c < b ? -4 : 0)); - if (y < 0) *n *= -1; - if (y != 0) { - if (x/y > 0 && *n <= 0) - *n += 8; - else if (x/y < 0 && *n >= 0) - *n -= 8; - } - } - return z; -} - -/* Implement round(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 (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 if (x < 0) { - t = floor(x); - return 0.5 < x - t ? t + 1 : t; - } else /* +/-0 and NaN */ - return x; /* retain sign of 0 */ -} - -/* Implement lround(x) */ -long pj_lround(double x) { - /* Default value for overflow + NaN + (x == LONG_MIN) */ - long r = LONG_MIN; - x = pj_round(x); - if (fabs(x) < -(double)r) /* Assume (double)LONG_MIN is exact */ - r = (long)x; - return r; -} - -#endif /* !(defined(HAVE_C99_MATH) && HAVE_C99_MATH) */ diff --git a/src/proj_math.h b/src/proj_math.h index 414df805..698654dd 100644 --- a/src/proj_math.h +++ b/src/proj_math.h @@ -61,29 +61,8 @@ extern "C" { #endif #endif -double pj_hypot(double x, double y); -double pj_log1p(double x); -double pj_asinh(double x); -double pj_atanh(double x); -double pj_copysign(double x, double y); -double pj_cbrt(double x); -double pj_remainder(double x, double y); -double pj_remquo(double x, double y, int* n); -double pj_round(double x); -long pj_lround(double x); int PROJ_DLL pj_isnan(double x); -#define hypot pj_hypot -#define log1p pj_log1p -#define asinh pj_asinh -#define atanh pj_atanh -#define copysign pj_copysign -#define cbrt pj_cbrt -#define remainder pj_remainder -#define remquo pj_remquo -#define round pj_round -#define lround pj_lround - #ifdef isnan #undef isnan #endif |