virtualx-engine/core/math/math_funcs.h
Hein-Pieter van Braam b696beea65 Correct hash behavior for floating point numbers
This fixes HashMap where a key or part of a key is a floating point
number. To fix this the following has been done:

* HashMap now takes an extra template argument Comparator. This class
gets used to compare keys. The default Comperator now works correctly
for common types and floating point numbets.

* Variant implements ::hash_compare() now. This function implements
nan-safe comparison for all types with components that contain floating
point numbers.

* Variant now has a VariantComparator which uses Variant::hash_compare()
safely compare floating point components of variant's types.

* The hash functions for floating point numbers will now normalize NaN
values so that all floating point numbers that are NaN hash to the same
value.

C++ module writers that want to use HashMap internally in their modules
can now also safeguard against this crash by defining their on
Comperator class that safely compares their types.

GDScript users, or writers of modules that don't use HashMap internally
in their modules don't need to do anything.

This fixes #7354 and fixes #6947.
2017-02-16 18:44:29 +01:00

347 lines
12 KiB
C++

/*************************************************************************/
/* math_funcs.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef MATH_FUNCS_H
#define MATH_FUNCS_H
#include "typedefs.h"
#include "math_defs.h"
#include "pcg.h"
#include <math.h>
#include <float.h>
#define Math_PI 3.14159265358979323846
#define Math_SQRT12 0.7071067811865475244008443621048490
#define Math_LN2 0.693147180559945309417
#define Math_NAN NAN
class Math {
static pcg32_random_t default_pcg;
public:
Math() {} // useless to instance
enum {
RANDOM_MAX=2147483647L
};
static _ALWAYS_INLINE_ double sin(double p_x) { return ::sin(p_x); }
static _ALWAYS_INLINE_ float sin(float p_x) { return ::sinf(p_x); }
static _ALWAYS_INLINE_ double cos(double p_x) { return ::cos(p_x); }
static _ALWAYS_INLINE_ float cos(float p_x) { return ::cosf(p_x); }
static _ALWAYS_INLINE_ double tan(double p_x) { return ::tan(p_x); }
static _ALWAYS_INLINE_ float tan(float p_x) { return ::tanf(p_x); }
static _ALWAYS_INLINE_ double sinh(double p_x) { return ::sinh(p_x); }
static _ALWAYS_INLINE_ float sinh(float p_x) { return ::sinhf(p_x); }
static _ALWAYS_INLINE_ double cosh(double p_x) { return ::cosh(p_x); }
static _ALWAYS_INLINE_ float cosh(float p_x) { return ::coshf(p_x); }
static _ALWAYS_INLINE_ double tanh(double p_x) { return ::tanh(p_x); }
static _ALWAYS_INLINE_ float tanh(float p_x) { return ::tanhf(p_x); }
static _ALWAYS_INLINE_ double asin(double p_x) { return ::asin(p_x); }
static _ALWAYS_INLINE_ float asin(float p_x) { return ::asinf(p_x); }
static _ALWAYS_INLINE_ double acos(double p_x) { return ::acos(p_x); }
static _ALWAYS_INLINE_ float acos(float p_x) { return ::acosf(p_x); }
static _ALWAYS_INLINE_ double atan(double p_x) { return ::atan(p_x); }
static _ALWAYS_INLINE_ float atan(float p_x) { return ::atanf(p_x); }
static _ALWAYS_INLINE_ double atan2(double p_y, double p_x) { return ::atan2(p_y,p_x); }
static _ALWAYS_INLINE_ float atan2(float p_y, float p_x) { return ::atan2f(p_y,p_x); }
static _ALWAYS_INLINE_ double sqrt(double p_x) { return ::sqrt(p_x); }
static _ALWAYS_INLINE_ float sqrt(float p_x) { return ::sqrtf(p_x); }
static _ALWAYS_INLINE_ double fmod(double p_x,double p_y) { return ::fmod(p_x,p_y); }
static _ALWAYS_INLINE_ float fmod(float p_x,float p_y) { return ::fmodf(p_x,p_y); }
static _ALWAYS_INLINE_ double floor(double p_x) { return ::floor(p_x); }
static _ALWAYS_INLINE_ float floor(float p_x) { return ::floorf(p_x); }
static _ALWAYS_INLINE_ double ceil(double p_x) { return ::ceil(p_x); }
static _ALWAYS_INLINE_ float ceil(float p_x) { return ::ceilf(p_x); }
static _ALWAYS_INLINE_ double pow(double p_x, double p_y) { return ::pow(p_x,p_y); }
static _ALWAYS_INLINE_ float pow(float p_x, float p_y) { return ::powf(p_x,p_y); }
static _ALWAYS_INLINE_ double log(double p_x) { return ::log(p_x); }
static _ALWAYS_INLINE_ float log(float p_x) { return ::logf(p_x); }
static _ALWAYS_INLINE_ double exp(double p_x) { return ::exp(p_x); }
static _ALWAYS_INLINE_ float exp(float p_x) { return ::expf(p_x); }
static _ALWAYS_INLINE_ bool is_nan(double p_val) { return (p_val!=p_val); }
static _ALWAYS_INLINE_ bool is_nan(float p_val) { return (p_val!=p_val); }
static _ALWAYS_INLINE_ bool is_inf(double p_val) {
#ifdef _MSC_VER
return !_finite(p_val);
#else
return isinf(p_val);
#endif
}
static _ALWAYS_INLINE_ bool is_inf(float p_val) {
#ifdef _MSC_VER
return !_finite(p_val);
#else
return isinf(p_val);
#endif
}
static _ALWAYS_INLINE_ double abs(double g) { return absd(g); }
static _ALWAYS_INLINE_ float abs(float g) { return absf(g); }
static _ALWAYS_INLINE_ int abs(int g) { return g > 0 ? g : -g; }
static _ALWAYS_INLINE_ double fposmod(double p_x,double p_y) { return (p_x>=0) ? Math::fmod(p_x,p_y) : p_y-Math::fmod(-p_x,p_y); }
static _ALWAYS_INLINE_ float fposmod(float p_x,float p_y) { return (p_x>=0) ? Math::fmod(p_x,p_y) : p_y-Math::fmod(-p_x,p_y); }
static _ALWAYS_INLINE_ double deg2rad(double p_y) { return p_y*Math_PI/180.0; }
static _ALWAYS_INLINE_ float deg2rad(float p_y) { return p_y*Math_PI/180.0; }
static _ALWAYS_INLINE_ double rad2deg(double p_y) { return p_y*180.0/Math_PI; }
static _ALWAYS_INLINE_ float rad2deg(float p_y) { return p_y*180.0/Math_PI; }
static _ALWAYS_INLINE_ double lerp(double a, double b, double c) { return a+(b-a)*c; }
static _ALWAYS_INLINE_ float lerp(float a, float b, float c) { return a+(b-a)*c; }
static _ALWAYS_INLINE_ double linear2db(double p_linear) { return Math::log( p_linear ) * 8.6858896380650365530225783783321; }
static _ALWAYS_INLINE_ float linear2db(float p_linear) { return Math::log( p_linear ) * 8.6858896380650365530225783783321; }
static _ALWAYS_INLINE_ double db2linear(double p_db) { return Math::exp( p_db * 0.11512925464970228420089957273422 ); }
static _ALWAYS_INLINE_ float db2linear(float p_db) { return Math::exp( p_db * 0.11512925464970228420089957273422 ); }
static _ALWAYS_INLINE_ double round(double p_val) { return (p_val>=0) ? Math::floor(p_val+0.5) : -Math::floor(-p_val+0.5); }
static _ALWAYS_INLINE_ float round(float p_val) { return (p_val>=0) ? Math::floor(p_val+0.5) : -Math::floor(-p_val+0.5); }
// double only, as these functions are mainly used by the editor and not performance-critical,
static double ease(double p_x, double p_c);
static int step_decimals(double p_step);
static double stepify(double p_value,double p_step);
static double dectime(double p_value,double p_amount, double p_step);
static uint32_t larger_prime(uint32_t p_val);
static void seed(uint64_t x=0);
static void randomize();
static uint32_t rand_from_seed(uint64_t *seed);
static uint32_t rand();
static _ALWAYS_INLINE_ double randf() { return (double)rand() / (double)Math::RANDOM_MAX; }
static _ALWAYS_INLINE_ float randd() { return (float)rand() / (float)Math::RANDOM_MAX; }
static double random(double from, double to);
static float random(float from, float to);
static real_t random(int from, int to) { return (real_t)random((real_t)from, (real_t)to); }
static _ALWAYS_INLINE_ bool isequal_approx(real_t a, real_t b) {
// TODO: Comparing floats for approximate-equality is non-trivial.
// Using epsilon should cover the typical cases in Godot (where a == b is used to compare two reals), such as matrix and vector comparison operators.
// A proper implementation in terms of ULPs should eventually replace the contents of this function.
// See https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/ for details.
return abs(a-b) < CMP_EPSILON;
}
static _ALWAYS_INLINE_ float absf(float g) {
union {
float f;
uint32_t i;
} u;
u.f=g;
u.i&=2147483647u;
return u.f;
}
static _ALWAYS_INLINE_ double absd(double g) {
union {
double d;
uint64_t i;
} u;
u.d=g;
u.i&=(uint64_t)9223372036854775807ll;
return u.d;
}
//this function should be as fast as possible and rounding mode should not matter
static _ALWAYS_INLINE_ int fast_ftoi(float a) {
static int b;
#if (defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0603) || WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP // windows 8 phone?
b = (int)((a>0.0) ? (a + 0.5):(a -0.5));
#elif defined(_MSC_VER) && _MSC_VER < 1800
__asm fld a
__asm fistp b
/*#elif defined( __GNUC__ ) && ( defined( __i386__ ) || defined( __x86_64__ ) )
// use AT&T inline assembly style, document that
// we use memory as output (=m) and input (m)
__asm__ __volatile__ (
"flds %1 \n\t"
"fistpl %0 \n\t"
: "=m" (b)
: "m" (a));*/
#else
b=lrintf(a); //assuming everything but msvc 2012 or earlier has lrint
#endif
return b;
}
#if defined(__GNUC__)
static _ALWAYS_INLINE_ int64_t dtoll(double p_double) { return (int64_t)p_double; } ///@TODO OPTIMIZE
static _ALWAYS_INLINE_ int64_t dtoll(float p_float) { return (int64_t)p_float; } ///@TODO OPTIMIZE and rename
#else
static _ALWAYS_INLINE_ int64_t dtoll(double p_double) { return (int64_t)p_double; } ///@TODO OPTIMIZE
static _ALWAYS_INLINE_ int64_t dtoll(float p_float) { return (int64_t)p_float; } ///@TODO OPTIMIZE and rename
#endif
static _ALWAYS_INLINE_ uint32_t halfbits_to_floatbits(uint16_t h)
{
uint16_t h_exp, h_sig;
uint32_t f_sgn, f_exp, f_sig;
h_exp = (h&0x7c00u);
f_sgn = ((uint32_t)h&0x8000u) << 16;
switch (h_exp) {
case 0x0000u: /* 0 or subnormal */
h_sig = (h&0x03ffu);
/* Signed zero */
if (h_sig == 0) {
return f_sgn;
}
/* Subnormal */
h_sig <<= 1;
while ((h_sig&0x0400u) == 0) {
h_sig <<= 1;
h_exp++;
}
f_exp = ((uint32_t)(127 - 15 - h_exp)) << 23;
f_sig = ((uint32_t)(h_sig&0x03ffu)) << 13;
return f_sgn + f_exp + f_sig;
case 0x7c00u: /* inf or NaN */
/* All-ones exponent and a copy of the significand */
return f_sgn + 0x7f800000u + (((uint32_t)(h&0x03ffu)) << 13);
default: /* normalized */
/* Just need to adjust the exponent and shift */
return f_sgn + (((uint32_t)(h&0x7fffu) + 0x1c000u) << 13);
}
}
static _ALWAYS_INLINE_ float halfptr_to_float(const uint16_t *h) {
union {
uint32_t u32;
float f32;
} u;
u.u32=halfbits_to_floatbits(*h);
return u.f32;
}
static _ALWAYS_INLINE_ uint16_t make_half_float(float f) {
union {
float fv;
uint32_t ui;
} ci;
ci.fv=f;
uint32_t x = ci.ui;
uint32_t sign = (unsigned short)(x >> 31);
uint32_t mantissa;
uint32_t exp;
uint16_t hf;
// get mantissa
mantissa = x & ((1 << 23) - 1);
// get exponent bits
exp = x & (0xFF << 23);
if (exp >= 0x47800000)
{
// check if the original single precision float number is a NaN
if (mantissa && (exp == (0xFF << 23)))
{
// we have a single precision NaN
mantissa = (1 << 23) - 1;
}
else
{
// 16-bit half-float representation stores number as Inf
mantissa = 0;
}
hf = (((uint16_t)sign) << 15) | (uint16_t)((0x1F << 10)) |
(uint16_t)(mantissa >> 13);
}
// check if exponent is <= -15
else if (exp <= 0x38000000)
{
/*// store a denorm half-float value or zero
exp = (0x38000000 - exp) >> 23;
mantissa >>= (14 + exp);
hf = (((uint16_t)sign) << 15) | (uint16_t)(mantissa);
*/
hf=0; //denormals do not work for 3D, convert to zero
}
else
{
hf = (((uint16_t)sign) << 15) |
(uint16_t)((exp - 0x38000000) >> 13) |
(uint16_t)(mantissa >> 13);
}
return hf;
}
};
#endif // MATH_FUNCS_H