math.java

一个开源的JAVA虚拟机

/*
    libaegisvm - The Aegis Virtual Machine for executing Java bytecode
    Copyright (C) 2001-2002  Philip W. L. Fong

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

package java.lang;

public final class Math {
    private static java.util.Random rg = null;
    private Math() { }

    public static final double E =
	Double.longBitsToDouble(0x4005bf0a8b145769L);
    public static final double PI =
	Double.longBitsToDouble(0x400921fb54442d18L);

    public static native double sin(double a);
    public static native double cos(double a);
    public static native double tan(double a);
    public static native double asin(double a);
    public static native double acos(double a);
    public static native double atan(double a);
    public static double toRadians(double angdeg) {
	return (angdeg / 180.0) * PI;
    }
    public static double toDegrees(double angrad) {
	return (angrad / PI) * 180.0;
    }
    public static native double exp(double a);
    public static native double log(double a);
    public static native double sqrt(double a);
    public static native double IEEEremainder(double f1, double f2);
    public static native double ceil(double a);
    public static native double floor(double a);
    public static native double rint(double a);
    public static native double atan2(double a, double b);
    public static native double pow(double a, double b);
    public static int round(float a) {
	if (a != a)
	    return 0;
	else if (a <= (float) Integer.MIN_VALUE)
	    return Integer.MIN_VALUE;
	else if (a >= (float) Integer.MAX_VALUE)
	    return Integer.MAX_VALUE;
	else
	    return (int) floor(a + 0.5f);
    }
    public static long round(double a) {
	if (a != a)
	    return 0L;
	else if (a <= (double) Long.MIN_VALUE)
	    return Long.MIN_VALUE;
	else if (a >= (double) Long.MAX_VALUE)
	    return Long.MAX_VALUE;
	else
	    return (long) floor(a + 0.5d);
    }

    public static synchronized double random() {
	if (rg == null)
	    rg = new java.util.Random();
	return rg.nextDouble();
    }
    public static int abs(int a) {
	return (a < 0) ? -a : a;
    }
    public static long abs(long a) {
	return (a < 0) ? -a : a;
    }
    public static float abs(float a) {
	return Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a));
    }
    public static double abs(double a) {
	return Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1);
    }
    public static int max(int a, int b) {
	return (a > b) ? a : b;
    }
    public static long max(long a, long b) {
	return (a > b) ? a : b;
    }
    public static float max(float a, float b) {
	if (a != a || b != b)
	    return Float.NaN;
	else if (a == 0.0f && b == 0.0f)
	    return (1.0f / a > 0.0f) ? a : b;
	else
	    return (a > b) ? a : b;
    }
    public static double max(double a, double b) {
	if (a != a || b != b)
	    return Double.NaN;
	else if (a == 0.0d && b == 0.0d)
	    return (1.0d / a > 0.0d) ? a : b;
	else
	    return (a > b) ? a : b;
    }
    public static int min(int a, int b) {
	return (a < b) ? a : b;
    }
    public static long min(long a, long b) {
	return (a < b) ? a : b;
    }
    public static float min(float a, float b) {
	if (a != 0 || b != b)
	    return Float.NaN;
	else if (a == 0.0f && b == 0.0f)
	    return (1.0f / a < 0.0f) ? a : b;
	else
	    return (a < b) ? a : b;
    }
    public static double min(double a, double b) {
	if (a != 0 || b != b)
	    return Double.NaN;
	else if (a == 0.0d && b == 0.0d)
	    return (1.0d / a < 0.0d) ? a : b;
	else
	    return (a < b) ? a : b;
    }
}