math工具类
public abstract class MathFP
{
private static int _fbits = 12;
private static int _digits = 4;
private static int _one = 4096;
private static int _fmask = 4095;
private static int _dmul = 10000;
private static int _flt = 0;
private static int _pi = 12868;
private static int[] e = { _one, 11134, 30266, 82270, 223636 };
public static int PI = _pi;
public static int E = e[1];
public static final int MAX_VALUE = 2147483647;
public static final int MIN_VALUE = -2147483647;
public static int setPrecision(int paramInt)
{
if ((paramInt > 12) || (paramInt < 0))
return _digits;
_fbits = paramInt;
_one = 1 << paramInt;
_flt = 12 - paramInt;
_digits = 0;
_dmul = 1;
_fmask = _one - 1;
PI = _pi >> _flt;
E = e[1] >> _flt;
int i = _one;
while (i != 0)
{
i /= 10;
_digits += 1;
_dmul *= 10;
}
return _digits;
}
public static int getPrecision()
{
return _fbits;
}
public static int toInt(int paramInt)
{
paramInt = round(paramInt, 0);
return (paramInt >> _fbits);
}
public static int toFP(int paramInt)
{
return (paramInt << _fbits);
}
public static int convert(int paramInt1, int paramInt2)
{
int i = (paramInt1 < 0) ? -1 : 1;
if (abs(paramInt2) < 13)
if (_fbits < paramInt2)
paramInt1 = paramInt1 + i * (1 << paramInt2 - _fbits >> 1) >> paramInt2 - _fbits;
else
paramInt1 <<= _fbits - paramInt2;
return paramInt1;
}
public static int toFP(String paramString)
{
int i = 0;
if (paramString.charAt(0) == '-')
i = 1;
String str = "-1";
int j = paramString.indexOf(46);
if (j >= 0)
{
for (str = paramString.substring(j + 1, paramString.length()); str.length() < _digits; str = str + "0");
if (str.length() > _digits)
str = str.substring(0, _digits);
}
else
{
j = paramString.length();
}
int k = 0;
if (i != j)
k = Integer.parseInt(paramString.substring(i, j));
int l = Integer.parseInt(str) + 1;
int i1 = (k << _fbits) + (l << _fbits) / _dmul;
if (i == 1)
i1 = -i1;
return i1;
}
public static String toString(int paramInt)
{
int i = 0;
if (paramInt < 0)
{
i = 1;
paramInt = -paramInt;
}
int j = paramInt >> _fbits;
int k = _dmul * (paramInt & _fmask) >> _fbits;
for (String str = Integer.toString(k); str.length() < _digits; str = "0" + str);
return ((i != 0) ? "-" : "") + Integer.toString(j) + "." + str;
}
public static String toString(int paramInt1, int paramInt2)
{
if (paramInt2 > _digits)
paramInt2 = _digits;
String str = toString(round(paramInt1, paramInt2));
return str.substring(0, str.length() - _digits + paramInt2);
}
public static int max(int paramInt1, int paramInt2)
{
return ((paramInt1 < paramInt2) ? paramInt2 : paramInt1);
}
public static int min(int paramInt1, int paramInt2)
{
return ((paramInt2 < paramInt1) ? paramInt2 : paramInt1);
}
public static int round(int paramInt1, int paramInt2)
{
int i = 10;
for (int j = 0; j < paramInt2; ++j)
i *= 10;
i = div(toFP(5), toFP(i));
if (paramInt1 < 0)
i = -i;
return (paramInt1 + i);
}
public static int mul(int paramInt1, int paramInt2)
{
int i = 0;
int j = _fbits;
int k = _fmask;
if ((paramInt1 & k) == 0)
return ((paramInt1 >> j) * paramInt2);
if ((paramInt2 & k) == 0)
return (paramInt1 * (paramInt2 >> j));
if (((paramInt1 < 0) && (paramInt2 > 0)) || ((paramInt1 > 0) && (paramInt2 < 0)))
i = 1;
if (paramInt1 < 0)
paramInt1 = -paramInt1;
if (paramInt2 < 0)
paramInt2 = -paramInt2;
while (max(paramInt1, paramInt2) >= 1 << 31 - --j)
{
paramInt1 >>= 1;
paramInt2 >>= 1;
k >>= 1;
}
int l = (paramInt1 >> j) * (paramInt2 >> j) << j;
int i1 = (paramInt1 & k) * (paramInt2 & k) >> j;
i1 += ((paramInt1 & (k ^ 0xFFFFFFFF)) * (paramInt2 & k) >> j);
l = l + i1 + ((paramInt1 & k) * (paramInt2 & (k ^ 0xFFFFFFFF)) >> j) << _fbits - j;
if (l < 0)
throw new ArithmeticException("Overflow");
return ((i != 0) ? -l : l);
}
public static int div(int paramInt1, int paramInt2)
{
int i = 0;
int j = _fbits;
if (paramInt2 == _one)
return paramInt1;
if ((paramInt2 & _fmask) == 0)
return (paramInt1 / (paramInt2 >> j));
if (((paramInt1 < 0) && (paramInt2 > 0)) || ((paramInt1 > 0) && (paramInt2 < 0)))
i = 1;
if (paramInt1 < 0)
paramInt1 = -paramInt1;
if (paramInt2 < 0)
paramInt2 = -paramInt2;
while (max(paramInt1, paramInt2) >= 1 << 31 - --j)
{
paramInt1 >>= 1;
paramInt2 >>= 1;
}
int k = (paramInt1 << j) / paramInt2 << _fbits - j;
return ((i != 0) ? -k : k);
}
public static int add(int paramInt1, int paramInt2)
{
return (paramInt1 + paramInt2);
}
public static int sub(int paramInt1, int paramInt2)
{
return (paramInt1 - paramInt2);
}
public static int abs(int paramInt)
{
if (paramInt < 0)
return (-paramInt);
return paramInt;
}
public static int sqrt(int paramInt1, int paramInt2)
{
if (paramInt1 < 0)
throw new ArithmeticException("Bad Input");
if (paramInt1 == 0)
return 0;
int i = paramInt1 + _one >> 1;
for (int j = 0; j < paramInt2; ++j)
i = i + div(paramInt1, i) >> 1;
if (i < 0)
throw new ArithmeticException("Overflow");
return i;
}
public static int sqrt(int paramInt)
{
return sqrt(paramInt, 16);
}
public static int sin(int paramInt)
{
int i = mul(paramInt, div(toFP(180), PI));
i %= toFP(360);
if (i < 0)
i = toFP(360) + i;
int j = i;
if ((i >= toFP(90)) && (i < toFP(270)))
j = toFP(180) - i;
else if ((i >= toFP(270)) && (i < toFP(360)))
j = -(toFP(360) - i);
int k = j / 90;
int l = mul(k, k);
int i1 = mul(mul(mul(mul(-18 >> _flt, l) + (326 >> _flt), l) - (2646 >> _flt), l) + (6434 >> _flt), k);
return i1;
}
public static int asin(int paramInt)
{
if (abs(paramInt) > _one)
throw new ArithmeticException("Bad Input");
int i = (paramInt < 0) ? 1 : 0;
if (paramInt < 0)
paramInt = -paramInt;
int j = mul(mul(mul(mul(35 >> _flt, paramInt) - (146 >> _flt), paramInt) + (347 >> _flt), paramInt) - (877 >> _flt), paramInt) + (6434 >> _flt);
int k = PI / 2 - mul(sqrt(_one - paramInt), j);
return ((i != 0) ? -k : k);
}
public static int cos(int paramInt)
{
return sin(PI / 2 - paramInt);
}
public static int acos(int paramInt)
{
return (PI / 2 - asin(paramInt));
}
public static int tan(int paramInt)
{
return div(sin(paramInt), cos(paramInt));
}
public static int cot(int paramInt)
{
return div(cos(paramInt), sin(paramInt));
}
public static int atan(int paramInt)
{
return asin(div(paramInt, sqrt(_one + mul(paramInt, paramInt))));
}
public static int exp(int paramInt)
{
if (paramInt == 0)
return _one;
int i = (paramInt < 0) ? 1 : 0;
paramInt = abs(paramInt);
int j = paramInt >> _fbits;
int k = _one;
for (int l = 0; l < j / 4; ++l)
k = mul(k, e[4] >> _flt);
if (j % 4 > 0)
k = mul(k, e[(j % 4)] >> _flt);
paramInt &= _fmask;
if (paramInt > 0)
{
int i1 = _one;
int i2 = 0;
int i3 = 1;
for (int i4 = 0; i4 < 16; ++i4)
{
i2 += i1 / i3;
i1 = mul(i1, paramInt);
i3 *= (i4 + 1);
if ((i3 > i1) || (i1 <= 0))
break;
if (i3 <= 0)
break;
}
k = mul(k, i2);
}
if (i != 0)
k = div(_one, k);
return k;
}
public static int log(int paramInt)
{
if (paramInt <= 0)
throw new ArithmeticException("Bad Input");
int i = 0;
int j = 0;
for (int k = 0; paramInt >= _one << 1; ++k)
paramInt >>= 1;
int l = k * (2839 >> _flt);
int i1 = 0;
if (paramInt < _one)
return (-log(div(_one, paramInt)));
paramInt -= _one;
for (int i2 = 1; i2 < 20; ++i2)
{
if (i == 0)
j = paramInt;
else
j = mul(i, paramInt);
if (j == 0)
break;
i1 += ((i2 % 2 == 0) ? -1 : 1) * j / i2;
i = j;
}
return (l + i1);
}
public static int pow(int paramInt1, int paramInt2)
{
int i = (paramInt2 < 0) ? 1 : 0;
int j = _one;
paramInt2 = abs(paramInt2);
int k = paramInt2 >> _fbits;
while (k-- > 0)
j = mul(j, paramInt1);
if (j < 0)
throw new ArithmeticException("Overflow");
if (paramInt1 != 0)
j = mul(j, exp(mul(log(paramInt1), paramInt2 & _fmask)));
else
j = 0;
if (i != 0)
return div(_one, j);
return j;
}
public static int atan2(int paramInt1, int paramInt2)
{
int i = 0;
if (paramInt2 > 0)
{
i = atan(div(paramInt1, paramInt2));
}
else if (paramInt2 < 0)
{
i = ((paramInt2 < 0) ? -PI : PI) - atan(abs(div(paramInt1, paramInt2)));
}
else
{
if ((paramInt2 == 0) && (paramInt1 == 0))
throw new ArithmeticException("Bad Input");
i = ((paramInt2 < 0) ? -PI : PI) / 2;
}
return i;
}
}
