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authorchai <chaifix@163.com>2020-11-10 18:46:11 +0800
committerchai <chaifix@163.com>2020-11-10 18:46:11 +0800
commit59e6235113a4d933811aa2cf6fdc8282ce394b9d (patch)
tree12410a230c5339ca88be6842c0dc811d5c6ec0ba /Runtime/Math/FloatConversion.h
parentf0807fc44dde14531759306317611bab87c8fccf (diff)
*window
Diffstat (limited to 'Runtime/Math/FloatConversion.h')
-rw-r--r--Runtime/Math/FloatConversion.h697
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diff --git a/Runtime/Math/FloatConversion.h b/Runtime/Math/FloatConversion.h
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@@ -0,0 +1,697 @@
+#ifndef FLOATCONVERSION_H
+#define FLOATCONVERSION_H
+
+#include <algorithm>
+#include <cmath>
+#include <limits>
+#include <math.h>
+
+#include "../../Runtime/Utilities/Type.h"
+#include "../../Runtime/Utilities/Assert.h"
+
+#if defined(SN_TARGET_PS3)
+# include <ppu_intrinsics.h>
+#elif defined(__GNUC__) && defined(__ppc__)
+# include <ppc_intrinsics.h>
+#endif
+
+#ifndef kPI
+#define kPI 3.14159265358979323846264338327950288419716939937510F
+#endif
+
+const float kBiggestFloatSmallerThanOne = 0.99999994f;
+const double kBiggestDoubleSmallerThanOne = 0.99999999999999989;
+
+#if defined(_XBOX)
+#define __FSELF __fself
+#elif defined(SN_TARGET_PS3)
+#define __FSELF __fsels
+#endif
+
+inline float FloatMin(float a, float b)
+{
+#if defined(_XBOX) || defined(SN_TARGET_PS3)
+ return __FSELF((a)-(b), b, a);
+#else
+ // return std::min(a, b);
+ return a < b ? a : b;
+#endif
+}
+
+inline float FloatMax(float a, float b)
+{
+#if defined(_XBOX) || defined(SN_TARGET_PS3)
+ return __FSELF((a)-(b), a, b);
+#else
+ //return std::max(a, b);
+ return a > b ? a : b;
+#endif
+}
+
+inline float Abs(float v)
+{
+#if defined(__ppc__) && (defined(__MWERKS__) || defined(SN_TARGET_PS3))
+ return __fabsf(v);
+#elif defined(_XBOX)
+ return __fabs(v);
+#else
+ return v < 0.0F ? -v : v;
+#endif
+}
+
+inline double Abs(double v)
+{
+ return v < 0.0 ? -v : v;
+}
+
+inline int Abs(int v)
+{
+ return v < 0 ? -v : v;
+}
+
+// Floor, ceil and round functions.
+//
+// When changing or implementing these functions, make sure the tests in MathTest.cpp
+// still pass.
+//
+// Floor: rounds to the largest integer smaller than or equal to the input parameter.
+// Ceil: rounds to the smallest integer larger than or equal to the input parameter.
+// Round: rounds to the nearest integer. Ties (0.5) are rounded up to the smallest integer
+// larger than or equal to the input parameter.
+// Chop/truncate: use a normal integer cast.
+//
+// Windows:
+// Casts are as fast as a straight fistp on an SSE equipped CPU. This is by far the most common
+// scenario and will result in the best code for most users. fistp will use the rounding mode set
+// in the control register (round to nearest by default), and needs fiddling to work properly.
+// This actually makes code that attempt to use fistp slower than a cast.
+// Unless we want round to nearest, in which case fistp should be the best choice, right? But
+// it is not. The default rounding mode is round to nearest, but in case of a tie (0.5), round to
+// nearest even is used. Thus 0.5 is rounded down to 0, 1.5 is rounded up to 2.
+// Conclusion - fistp is useless without stupid fiddling around that actually makes is slower than
+// an SSE cast.
+//
+// OS X Intel:
+// Needs investigating
+//
+// OS X PowerPC:
+// Needs investigating
+//
+// Xbox 360:
+// Needs investigating
+//
+// PS3:
+// Needs investigating
+//
+// iPhone:
+// Needs investigating
+//
+// Android:
+// Needs investigating
+
+
+inline int FloorfToInt(float f)
+{
+ DebugAssertIf(f < INT_MIN || f > INT_MAX);
+ return f >= 0 ? (int)f : (int)(f - kBiggestFloatSmallerThanOne);
+}
+
+inline UInt32 FloorfToIntPos(float f)
+{
+ DebugAssertIf(f < 0 || f > UINT_MAX);
+ return (UInt32)f;
+}
+
+inline float Floorf(float f)
+{
+ // Use std::floor().
+ // We are interested in reliable functions that do not lose precision.
+ // Casting to int and back to float would not be helpful.
+ return floor(f);
+}
+
+inline double Floord(double f)
+{
+ // Use std::floor().
+ // We are interested in reliable functions that do not lose precision.
+ // Casting to int and back to float would not be helpful.
+ return floor(f);
+}
+
+
+inline int CeilfToInt(float f)
+{
+ DebugAssertIf(f < INT_MIN || f > INT_MAX);
+ return f >= 0 ? (int)(f + kBiggestFloatSmallerThanOne) : (int)(f);
+}
+
+inline UInt32 CeilfToIntPos(float f)
+{
+ DebugAssertIf(f < 0 || f > UINT_MAX);
+ return (UInt32)(f + kBiggestFloatSmallerThanOne);
+}
+
+inline float Ceilf(float f)
+{
+ // Use std::ceil().
+ // We are interested in reliable functions that do not lose precision.
+ // Casting to int and back to float would not be helpful.
+ return ceil(f);
+}
+
+inline double Ceild(double f)
+{
+ // Use std::ceil().
+ // We are interested in reliable functions that do not lose precision.
+ // Casting to int and back to float would not be helpful.
+ return ceil(f);
+}
+
+
+inline int RoundfToInt(float f)
+{
+ return FloorfToInt(f + 0.5F);
+}
+
+inline UInt32 RoundfToIntPos(float f)
+{
+ return FloorfToIntPos(f + 0.5F);
+}
+
+inline float Roundf(float f)
+{
+ return Floorf(f + 0.5F);
+}
+
+inline double Roundf(double f)
+{
+ return Floord(f + 0.5);
+}
+
+
+/// Fast conversion of float [0...1] to 0 ... 65535
+inline int NormalizedToWord(float f)
+{
+ f = FloatMax(f, 0.0F);
+ f = FloatMin(f, 1.0F);
+ return RoundfToIntPos(f * 65535.0f);
+}
+
+/// Fast conversion of float [0...1] to 0 ... 65535
+inline float WordToNormalized(int p)
+{
+ AssertIf(p < 0 || p > 65535);
+ return (float)p / 65535.0F;
+}
+
+/// Fast conversion of float [0...1] to 0 ... 255
+inline int NormalizedToByte(float f)
+{
+ f = FloatMax(f, 0.0F);
+ f = FloatMin(f, 1.0F);
+ return RoundfToIntPos(f * 255.0f);
+}
+
+/// Fast conversion of float [0...1] to 0 ... 255
+inline float ByteToNormalized(int p)
+{
+ AssertIf(p < 0 || p > 255);
+ return (float)p / 255.0F;
+}
+
+
+// Returns float remainder for t / length
+inline float Repeat(float t, float length)
+{
+ return t - Floorf(t / length) * length;
+}
+
+// Returns double remainder for t / length
+inline double RepeatD(double t, double length)
+{
+ return t - floor(t / length) * length;
+}
+
+// Returns relative angle on the interval (-pi, pi]
+inline float DeltaAngleRad(float current, float target)
+{
+ float delta = Repeat((target - current), 2 * kPI);
+ if (delta > kPI)
+ delta -= 2 * kPI;
+ return delta;
+}
+
+// Returns true if the distance between f0 and f1 is smaller than epsilon
+inline bool CompareApproximately(float f0, float f1, float epsilon = 0.000001F)
+{
+ float dist = (f0 - f1);
+ dist = Abs(dist);
+ return dist < epsilon;
+}
+
+/// CopySignf () returns x with its sign changed to y's.
+inline float CopySignf(float x, float y)
+{
+ union
+ {
+ float f;
+ UInt32 i;
+ } u, u0, u1;
+ u0.f = x; u1.f = y;
+ UInt32 a = u0.i;
+ UInt32 b = u1.i;
+ SInt32 mask = 1 << 31;
+ UInt32 sign = b & mask;
+ a &= ~mask;
+ a |= sign;
+
+ u.i = a;
+ return u.f;
+}
+
+inline int CompareFloatRobustSignUtility(float A)
+{
+ // The sign bit of a number is the high bit.
+ union
+ {
+ float f;
+ int i;
+ } u;
+ u.f = A;
+ return (u.i) & 0x80000000;
+}
+
+inline bool CompareFloatRobust(float f0, float f1, int maxUlps = 10)
+{
+ // After adjusting floats so their representations are lexicographically
+ // ordered as twos-complement integers a very small positive number
+ // will compare as 'close' to a very small negative number. If this is
+ // not desireable, and if you are on a platform that supports
+ // subnormals (which is the only place the problem can show up) then
+ // you need this check.
+ // The check for A == B is because zero and negative zero have different
+ // signs but are equal to each other.
+ if (CompareFloatRobustSignUtility(f0) != CompareFloatRobustSignUtility(f1))
+ return f0 == f1;
+
+ union
+ {
+ float f;
+ int i;
+ } u0, u1;
+ u0.f = f0;
+ u1.f = f1;
+ int aInt = u0.i;
+ // Make aInt lexicographically ordered as a twos-complement int
+ if (aInt < 0)
+ aInt = 0x80000000 - aInt;
+ // Make bInt lexicographically ordered as a twos-complement int
+ int bInt = u1.i;
+ if (bInt < 0)
+ bInt = 0x80000000 - bInt;
+
+ // Now we can compare aInt and bInt to find out how far apart A and B
+ // are.
+ int intDiff = Abs(aInt - bInt);
+ if (intDiff <= maxUlps)
+ return true;
+ return false;
+}
+
+// Returns the t^2
+template<class T>
+T Sqr(const T& t)
+{
+ return t * t;
+}
+
+#define kDeg2Rad (2.0F * kPI / 360.0F)
+#define kRad2Deg (1.F / kDeg2Rad)
+
+inline float Deg2Rad(float deg)
+{
+ // TODO : should be deg * kDeg2Rad, but can't be changed,
+ // because it changes the order of operations and that affects a replay in some RegressionTests
+ return deg / 360.0F * 2.0F * kPI;
+}
+
+inline float Rad2Deg(float rad)
+{
+ // TODO : should be rad * kRad2Deg, but can't be changed,
+ // because it changes the order of operations and that affects a replay in some RegressionTests
+ return rad / 2.0F / kPI * 360.0F;
+}
+
+inline float Lerp(float from, float to, float t)
+{
+ return to * t + from * (1.0F - t);
+}
+
+inline bool IsNAN(float value)
+{
+#if defined __APPLE_CC__
+ return value != value;
+#elif _MSC_VER
+ return _isnan(value) != 0;
+#else
+ return isnan(value);
+#endif
+}
+
+inline bool IsNAN(double value)
+{
+#if defined __APPLE_CC__
+ return value != value;
+#elif _MSC_VER
+ return _isnan(value) != 0;
+#else
+ return isnan(value);
+#endif
+}
+
+inline bool IsPlusInf(float value) { return value == std::numeric_limits<float>::infinity(); }
+inline bool IsMinusInf(float value) { return value == -std::numeric_limits<float>::infinity(); }
+
+inline bool IsFinite(const float& value)
+{
+ // Returns false if value is NaN or +/- infinity
+ UInt32 intval = *reinterpret_cast<const UInt32*>(&value);
+ return (intval & 0x7f800000) != 0x7f800000;
+}
+
+inline bool IsFinite(const double& value)
+{
+ // Returns false if value is NaN or +/- infinity
+ UInt64 intval = *reinterpret_cast<const UInt64*>(&value);
+ return (intval & 0x7ff0000000000000LL) != 0x7ff0000000000000LL;
+}
+
+inline float InvSqrt(float p) { return 1.0F / sqrt(p); }
+inline float Sqrt(float p) { return sqrt(p); }
+
+/// - Almost highest precision sqrt
+/// - Returns 0 if value is 0 or -1
+/// inline float FastSqrt (float value)
+
+/// - Almost highest precision inv sqrt
+/// - if value == 0 or -0 it returns 0.
+/// inline float FastInvSqrt (float value)
+
+/// - Low precision inv sqrt approximately
+/// - if value == 0 or -0 it returns nan or undefined
+/// inline float FastestInvSqrt (float value)
+
+#if defined(__ppc__) || defined(SN_TARGET_PS3)
+
+#if UNITY_WII
+// Copied from <CodeWarrior>\PowerPC_EABI_Support\MSL\MSL_C\PPC_EABI\Include\math_ppc_inlines.h
+// Requires hardware floating to be enabled
+// P.S I've also profiled with function below which uses fabs(x) == 0.0F, it's two times slower than this one
+inline float FastSqrt(float x)
+{
+ static const double _half = .5f;
+ static const double _three = 3.0f;
+
+ if (x > 0.0f)
+ {
+ double xd = (double)x;
+ double guess = __frsqrte(xd); /* returns an approximation to */
+ guess = _half * guess*(_three - guess * guess*xd); /* now have 12 sig bits */
+ guess = _half * guess*(_three - guess * guess*xd); /* now have 24 sig bits */
+ return (float)(xd * guess);
+ }
+ else if (x < 0.0)
+ return NAN;
+ else
+ return x;
+}
+#else
+/// - Accurate to 1 bit precision
+/// - returns zero if x is zero
+inline float FastSqrt(float x)
+{
+ const float half = 0.5;
+ const float one = 1.0;
+ float B, y0, y1;
+
+ // This'll NaN if it hits frsqrte. Handle both +0.0 and -0.0
+ if (fabs(x) == 0.0F)
+ return x;
+
+ B = x;
+
+#if defined(__GNUC__) && !defined(SN_TARGET_PS3)
+ y0 = __frsqrtes(B);
+#else
+ y0 = __frsqrte(B);
+#endif
+ // First refinement step
+
+ y1 = y0 + half * y0*(one - B * y0*y0);
+
+ // Second refinement step -- copy the output of the last step to the input of this step
+
+ y0 = y1;
+ y1 = y0 + half * y0*(one - B * y0*y0);
+
+ // Get sqrt(x) from x * 1/sqrt(x)
+ return x * y1;
+}
+#endif
+
+/// - Accurate to 1 bit precision
+/// - returns zero if f is zero
+inline float FastInvSqrt(float f)
+{
+ float result;
+ float estimate, estimate2;
+ float oneHalf = 0.5f;
+ float one = oneHalf + oneHalf;
+ //Calculate a 5 bit starting estimate for the reciprocal sqrt
+#if defined(__GNUC__) && !defined(SN_TARGET_PS3)
+ estimate = estimate2 = __frsqrtes(f);
+#else
+ estimate = estimate2 = __frsqrte(f);
+#endif
+
+ //if you require less precision, you may reduce the number of loop iterations
+ estimate = estimate + oneHalf * estimate * (one - f * estimate * estimate);
+ estimate = estimate + oneHalf * estimate * (one - f * estimate * estimate);
+
+#if defined(__GNUC__) && !defined(SN_TARGET_PS3)
+ result = __fsels(-f, estimate2, estimate);
+#else
+ result = __fsel(-f, estimate2, estimate);
+#endif
+ return result;
+}
+
+/// Fast inverse sqrt function
+inline float FastestInvSqrt(float value)
+{
+#if defined (__ppc__) && (defined (__MWERKS__) || defined(SN_TARGET_PS3))
+ return (float)__frsqrte(value);
+#elif defined (__ppc__)
+ return (float)__frsqrtes(value);
+#else
+ return 1.0F / sqrtf(value);
+#endif
+}
+
+#else
+
+inline float FastSqrt(float value)
+{
+ return sqrtf(value);
+}
+
+inline float FastInvSqrt(float f)
+{
+ // The Newton iteration trick used in FastestInvSqrt is a bit faster on
+ // Pentium4 / Windows, but lower precision. Doing two iterations is precise enough,
+ // but actually a bit slower.
+ if (fabs(f) == 0.0F)
+ return f;
+ return 1.0F / sqrtf(f);
+}
+
+inline float FastestInvSqrt(float f)
+{
+ union
+ {
+ float f;
+ int i;
+ } u;
+ float fhalf = 0.5f*f;
+ u.f = f;
+ int i = u.i;
+ i = 0x5f3759df - (i >> 1);
+ u.i = i;
+ f = u.f;
+ f = f * (1.5f - fhalf * f*f);
+ // f = f*(1.5f - fhalf*f*f); // uncommenting this would be two iterations
+ return f;
+}
+
+#endif
+
+inline float SqrtImpl(float f)
+{
+#if UNITY_WII || UNITY_FLASH
+ return FastSqrt(f);
+#else
+ return sqrt(f);
+#endif
+}
+inline float Sin(float f)
+{
+ return sinf(f);
+}
+
+inline float Pow(float f, float f2)
+{
+ return powf(f, f2);
+}
+
+inline float Cos(float f)
+{
+ return cosf(f);
+}
+
+inline float Sign(float f)
+{
+#if defined(_XBOX)
+ return __fsel(f, 1.0f, -1.0f);
+#else
+ if (f < 0.0F)
+ return -1.0F;
+ else
+ return 1.0;
+#endif
+}
+
+#if UNITY_EDITOR
+
+class FloatToHalfConverter
+{
+public:
+ FloatToHalfConverter();
+
+ void Convert(const float& src, UInt16& dest)
+ {
+ UInt32 bits = *reinterpret_cast<const UInt32*>(&src);
+ UInt8 index = UInt8(bits >> 23);
+ UInt32 sign = bits & 0x80000000;
+ UInt32 mantissa = bits & 0x007fffff;
+ dest = (sign >> 16) | m_ExponentTable[index] | (mantissa >> m_MantissaShift[index]);
+ }
+
+private:
+ UInt16 m_ExponentTable[256];
+ UInt8 m_MantissaShift[256];
+};
+
+extern FloatToHalfConverter g_FloatToHalf;
+
+#endif // UNITY_EDITOR
+
+#if UNITY_SUPPORTS_SSE
+#include "Runtime/Math/Simd/SimdMath.h"
+
+#define SSE_CONST4(name, val) static const ALIGN16 UInt32 name[4] = { (val), (val), (val), (val) }
+#define CONST_M128I(name) *(const __m128i *)&name
+
+static ALIGN16 UInt16 source[] = { 0,0,0,0,0,0,0,0 };
+static ALIGN16 float destination[] = { 0.0,0.0,0.0,0.0 };
+
+static void HalfToFloat(UInt16 src, float& dest)
+{
+ SSE_CONST4(mask_nosign, 0x7fff);
+ SSE_CONST4(smallest_normal, 0x0400);
+ SSE_CONST4(infinity, 0x7c00);
+ SSE_CONST4(expadjust_normal, (127 - 15) << 23);
+ SSE_CONST4(magic_denorm, 113 << 23);
+
+ source[0] = src;
+ __m128i in = _mm_loadu_si128(reinterpret_cast<const __m128i*>(source));
+ __m128i mnosign = CONST_M128I(mask_nosign);
+ __m128i eadjust = CONST_M128I(expadjust_normal);
+ __m128i smallest = CONST_M128I(smallest_normal);
+ __m128i infty = CONST_M128I(infinity);
+ __m128i expmant = _mm_and_si128(mnosign, in);
+ __m128i justsign = _mm_xor_si128(in, expmant);
+ __m128i b_notinfnan = _mm_cmpgt_epi32(infty, expmant);
+ __m128i b_isdenorm = _mm_cmpgt_epi32(smallest, expmant);
+ __m128i shifted = _mm_slli_epi32(expmant, 13);
+ __m128i adj_infnan = _mm_andnot_si128(b_notinfnan, eadjust);
+ __m128i adjusted = _mm_add_epi32(eadjust, shifted);
+ __m128i den1 = _mm_add_epi32(shifted, CONST_M128I(magic_denorm));
+ __m128i adjusted2 = _mm_add_epi32(adjusted, adj_infnan);
+ __m128 den2 = _mm_sub_ps(_mm_castsi128_ps(den1), *(const __m128 *)&magic_denorm);
+ __m128 adjusted3 = _mm_and_ps(den2, _mm_castsi128_ps(b_isdenorm));
+ __m128 adjusted4 = _mm_andnot_ps(_mm_castsi128_ps(b_isdenorm), _mm_castsi128_ps(adjusted2));
+ __m128 adjusted5 = _mm_or_ps(adjusted3, adjusted4);
+ __m128i sign = _mm_slli_epi32(justsign, 16);
+ __m128 out = _mm_or_ps(adjusted5, _mm_castsi128_ps(sign));
+ _mm_storeu_ps(destination, out);
+ dest = destination[0];
+#undef SSE_CONST4
+#undef CONST_M128I
+}
+
+#else
+
+static void HalfToFloat(UInt16 src, float& dest)
+{
+ // Integer alias
+ UInt32& bits = *reinterpret_cast<UInt32*>(&dest);
+
+ // Based on Fabian Giesen's public domain half_to_float_fast3
+ static const UInt32 magic = { 113 << 23 };
+ const float& magicFloat = *reinterpret_cast<const float*>(&magic);
+ static const UInt32 shiftedExp = 0x7c00 << 13; // exponent mask after shift
+
+ // Mask out sign bit
+ bits = src & 0x7fff;
+ if (bits)
+ {
+ // Move exponent + mantissa to correct bits
+ bits <<= 13;
+ UInt32 exponent = bits & shiftedExp;
+ if (exponent == 0)
+ {
+ // Handle denormal
+ bits += magic;
+ dest -= magicFloat;
+ }
+ else if (exponent == shiftedExp) // Inf/NaN
+ bits += (255 - 31) << 23;
+ else
+ bits += (127 - 15) << 23;
+ }
+
+ // Copy sign bit
+ bits |= (src & 0x8000) << 16;
+}
+
+#endif
+
+using std::cos;
+using std::pow;
+using std::atan2;
+using std::acos;
+using std::sin;
+using std::sqrt;
+using std::log;
+using std::exp;
+
+// On non-C99 platforms log2 is not available, so approximate it.
+#if UNITY_WIN || UNITY_XENON || UNITY_ANDROID || UNITY_FLASH || UNITY_WEBGL
+#define kNaturalLogarithm2 0.693147180559945309417
+#define Log2(x) (logf(x) / kNaturalLogarithm2)
+#else
+#define Log2(x) log2f(x)
+#endif
+
+
+#endif