package org.jcodec.common.tools;
import static java.lang.Math.max;
/**
* This class is part of JCodec ( www.jcodec.org ) This software is distributed
* under FreeBSD License
*
* @author The JCodec project
*
*/
public class MathUtil {
private static final int[] logTab = new int[] { 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 };
private static final int[] reverseTab = new int[] { 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90,
0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8,
0x38, 0xB8, 0x78, 0xF8, 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4,
0x74, 0xF4, 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 0x0A, 0x8A,
0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, 0x06, 0x86, 0x46, 0xC6,
0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE,
0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99,
0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5,
0x35, 0xB5, 0x75, 0xF5, 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD,
0x7D, 0xFD, 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, 0x07, 0x87,
0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, 0x0F, 0x8F, 0x4F, 0xCF,
0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF };
public static int log2(int v) {
int n = 0;
if ((v & 0xffff0000) != 0) {
v >>= 16;
n += 16;
}
if ((v & 0xff00) != 0) {
v >>= 8;
n += 8;
}
n += logTab[v];
return n;
}
public static int log2l(long v) {
int n = 0;
if ((v & 0xffffffff00000000L) != 0) {
v >>= 32;
n += 32;
}
if ((v & 0xffff0000L) != 0) {
v >>= 16;
n += 16;
}
if ((v & 0xff00L) != 0) {
v >>= 8;
n += 8;
}
n += logTab[(int) v];
return n;
}
public static int log2Slow(int val) {
int i = 0;
while ((val & 0x80000000) == 0) {
val <<= 1;
i++;
}
return 31 - i;
}
public static int gcd(int a, int b) {
if (b != 0)
return gcd(b, a % b);
else
return a;
}
public static long gcdLong(long a, long b) {
if (b != 0)
return gcdLong(b, a % b);
else
return a;
}
public static final int clip(int val, int from, int to) {
return val < from ? from : (val > to ? to : val);
}
public static final int clipMax(int val, int max) {
return val < max ? val : max;
}
public static int cubeRoot(int n) {
// TODO Auto-generated method stub
return 0;
}
public static final int reverse(int b) {
return reverseTab[b & 0xff];
}
public static int nextPowerOfTwo(int n) {
n = n - 1;
n = n | (n >> 1);
n = n | (n >> 2);
n = n | (n >> 4);
n = n | (n >> 8);
n = n | (n >> 16);
n = n + 1;
return n;
}
public static final int abs(int val) {
int sign = (val >> 31);
return (val ^ sign) - sign;
}
public static final int golomb(int signedLevel) {
if (signedLevel == 0)
return 0;
return (abs(signedLevel) << 1) - (~signedLevel >>> 31);
}
public static final int toSigned(int val, int sign) {
return (val ^ sign) - sign;
}
public static final int sign(int val) {
return -(val >> 31);
}
public static int wrap(int picNo, int maxFrames) {
return picNo < 0 ? picNo + maxFrames : (picNo >= maxFrames ? picNo - maxFrames : picNo);
}
public static int max3(int a, int b, int c) {
return max(max(a, b), c);
}
}