* Remove some useless files
git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9297 75d07b2b-3a1a-0410-a2c5-0572b91ccdca
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package com.jme3.util;
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/**
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* The wrapper for the primitive type {@code int}.
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* <p>
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* As with the specification, this implementation relies on code laid out in <a
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* href="http://www.hackersdelight.org/">Henry S. Warren, Jr.'s Hacker's
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* Delight, (Addison Wesley, 2002)</a> as well as <a
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* href="http://aggregate.org/MAGIC/">The Aggregate's Magic Algorithms</a>.
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*
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* @see java.lang.Number
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* @since 1.1
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*/
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public final class FastInteger {
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/**
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* Constant for the maximum {@code int} value, 2<sup>31</sup>-1.
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*/
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public static final int MAX_VALUE = 0x7FFFFFFF;
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/**
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* Constant for the minimum {@code int} value, -2<sup>31</sup>.
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*/
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public static final int MIN_VALUE = 0x80000000;
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/**
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* Constant for the number of bits needed to represent an {@code int} in
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* two's complement form.
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*
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* @since 1.5
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*/
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public static final int SIZE = 32;
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/*
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* Progressively smaller decimal order of magnitude that can be represented
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* by an instance of Integer. Used to help compute the String
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* representation.
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*/
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private static final int[] decimalScale = new int[] { 1000000000, 100000000,
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10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 };
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/**
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* Converts the specified integer into its decimal string representation.
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* The returned string is a concatenation of a minus sign if the number is
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* negative and characters from '0' to '9'.
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*
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* @param value
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* the integer to convert.
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* @return the decimal string representation of {@code value}.
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*/
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public static boolean toCharArray(int value, char[] output) {
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if (value == 0)
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{
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output[0] = '0';
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output[1] = 0;
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return true;
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}
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// Faster algorithm for smaller Integers
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if (value < 1000 && value > -1000) {
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int positive_value = value < 0 ? -value : value;
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int first_digit = 0;
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if (value < 0) {
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output[0] = '-';
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first_digit++;
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}
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int last_digit = first_digit;
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int quot = positive_value;
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do {
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int res = quot / 10;
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int digit_value = quot - ((res << 3) + (res << 1));
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digit_value += '0';
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output[last_digit++] = (char) digit_value;
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quot = res;
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} while (quot != 0);
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int count = last_digit--;
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do {
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char tmp = output[last_digit];
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output[last_digit--] = output[first_digit];
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output[first_digit++] = tmp;
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} while (first_digit < last_digit);
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output[count] = 0;
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return true;
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}
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if (value == MIN_VALUE) {
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System.arraycopy("-2147483648".toCharArray(), 0, output, 0, 12);
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output[12] = 0;
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return true;
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}
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int positive_value = value < 0 ? -value : value;
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byte first_digit = 0;
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if (value < 0) {
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output[0] = '-';
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first_digit++;
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}
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byte last_digit = first_digit;
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byte count;
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int number;
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boolean start = false;
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for (int i = 0; i < 9; i++) {
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count = 0;
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if (positive_value < (number = decimalScale[i])) {
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if (start) {
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output[last_digit++] = '0';
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}
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continue;
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}
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if (i > 0) {
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number = (decimalScale[i] << 3);
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if (positive_value >= number) {
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positive_value -= number;
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count += 8;
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}
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number = (decimalScale[i] << 2);
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if (positive_value >= number) {
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positive_value -= number;
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count += 4;
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}
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}
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number = (decimalScale[i] << 1);
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if (positive_value >= number) {
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positive_value -= number;
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count += 2;
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}
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if (positive_value >= decimalScale[i]) {
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positive_value -= decimalScale[i];
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count++;
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}
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if (count > 0 && !start) {
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start = true;
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}
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if (start) {
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output[last_digit++] = (char) (count + '0');
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}
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}
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output[last_digit++] = (char) (positive_value + '0');
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output[last_digit] = 0;
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count = last_digit--;
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return true;
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}
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/**
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* Determines the highest (leftmost) bit of the specified integer that is 1
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* and returns the bit mask value for that bit. This is also referred to as
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* the Most Significant 1 Bit. Returns zero if the specified integer is
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* zero.
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*
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* @param i
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* the integer to examine.
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* @return the bit mask indicating the highest 1 bit in {@code i}.
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* @since 1.5
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*/
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public static int highestOneBit(int i) {
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i |= (i >> 1);
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i |= (i >> 2);
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i |= (i >> 4);
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i |= (i >> 8);
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i |= (i >> 16);
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return (i & ~(i >>> 1));
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}
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/**
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* Determines the lowest (rightmost) bit of the specified integer that is 1
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* and returns the bit mask value for that bit. This is also referred
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* to as the Least Significant 1 Bit. Returns zero if the specified integer
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* is zero.
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*
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* @param i
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* the integer to examine.
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* @return the bit mask indicating the lowest 1 bit in {@code i}.
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* @since 1.5
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*/
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public static int lowestOneBit(int i) {
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return (i & (-i));
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}
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/**
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* Determines the number of leading zeros in the specified integer prior to
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* the {@link #highestOneBit(int) highest one bit}.
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*
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* @param i
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* the integer to examine.
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* @return the number of leading zeros in {@code i}.
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* @since 1.5
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*/
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public static int numberOfLeadingZeros(int i) {
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i |= i >> 1;
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i |= i >> 2;
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i |= i >> 4;
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i |= i >> 8;
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i |= i >> 16;
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return bitCount(~i);
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}
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/**
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* Determines the number of trailing zeros in the specified integer after
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* the {@link #lowestOneBit(int) lowest one bit}.
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*
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* @param i
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* the integer to examine.
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* @return the number of trailing zeros in {@code i}.
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* @since 1.5
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*/
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public static int numberOfTrailingZeros(int i) {
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return bitCount((i & -i) - 1);
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}
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/**
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* Counts the number of 1 bits in the specified integer; this is also
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* referred to as population count.
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*
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* @param i
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* the integer to examine.
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* @return the number of 1 bits in {@code i}.
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* @since 1.5
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*/
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public static int bitCount(int i) {
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i -= ((i >> 1) & 0x55555555);
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i = (i & 0x33333333) + ((i >> 2) & 0x33333333);
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i = (((i >> 4) + i) & 0x0F0F0F0F);
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i += (i >> 8);
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i += (i >> 16);
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return (i & 0x0000003F);
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}
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/**
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* Rotates the bits of the specified integer to the left by the specified
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* number of bits.
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*
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* @param i
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* the integer value to rotate left.
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* @param distance
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* the number of bits to rotate.
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* @return the rotated value.
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* @since 1.5
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*/
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public static int rotateLeft(int i, int distance) {
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if (distance == 0) {
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return i;
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}
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/*
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* According to JLS3, 15.19, the right operand of a shift is always
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* implicitly masked with 0x1F, which the negation of 'distance' is
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* taking advantage of.
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*/
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return ((i << distance) | (i >>> (-distance)));
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}
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/**
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* Rotates the bits of the specified integer to the right by the specified
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* number of bits.
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*
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* @param i
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* the integer value to rotate right.
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* @param distance
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* the number of bits to rotate.
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* @return the rotated value.
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* @since 1.5
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*/
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public static int rotateRight(int i, int distance) {
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if (distance == 0) {
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return i;
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}
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/*
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* According to JLS3, 15.19, the right operand of a shift is always
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* implicitly masked with 0x1F, which the negation of 'distance' is
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* taking advantage of.
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*/
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return ((i >>> distance) | (i << (-distance)));
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}
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/**
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* Reverses the order of the bytes of the specified integer.
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*
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* @param i
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* the integer value for which to reverse the byte order.
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* @return the reversed value.
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* @since 1.5
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*/
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public static int reverseBytes(int i) {
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int b3 = i >>> 24;
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int b2 = (i >>> 8) & 0xFF00;
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int b1 = (i & 0xFF00) << 8;
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int b0 = i << 24;
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return (b0 | b1 | b2 | b3);
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}
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/**
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* Reverses the order of the bits of the specified integer.
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*
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* @param i
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* the integer value for which to reverse the bit order.
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* @return the reversed value.
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* @since 1.5
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*/
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public static int reverse(int i) {
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// From Hacker's Delight, 7-1, Figure 7-1
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i = (i & 0x55555555) << 1 | (i >> 1) & 0x55555555;
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i = (i & 0x33333333) << 2 | (i >> 2) & 0x33333333;
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i = (i & 0x0F0F0F0F) << 4 | (i >> 4) & 0x0F0F0F0F;
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return reverseBytes(i);
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}
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/**
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* Returns the value of the {@code signum} function for the specified
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* integer.
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*
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* @param i
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* the integer value to check.
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* @return -1 if {@code i} is negative, 1 if {@code i} is positive, 0 if
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* {@code i} is zero.
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* @since 1.5
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*/
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public static int signum(int i) {
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return (i == 0 ? 0 : (i < 0 ? -1 : 1));
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}
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/**
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* Returns a {@code Integer} instance for the specified integer value.
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* <p>
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* If it is not necessary to get a new {@code Integer} instance, it is
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* recommended to use this method instead of the constructor, since it
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* maintains a cache of instances which may result in better performance.
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*
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* @param i
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* the integer value to store in the instance.
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* @return a {@code Integer} instance containing {@code i}.
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* @since 1.5
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*/
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public static Integer valueOf(int i) {
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if (i < -128 || i > 127) {
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return new Integer(i);
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}
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return valueOfCache.CACHE [i+128];
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}
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static class valueOfCache {
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/**
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* <p>
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* A cache of instances used by {@link Integer#valueOf(int)} and auto-boxing.
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*/
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static final Integer[] CACHE = new Integer[256];
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static {
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for(int i=-128; i<=127; i++) {
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CACHE[i+128] = new Integer(i);
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}
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}
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}
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}
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@ -1,431 +0,0 @@
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package jme3tools.android;
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import java.util.Random;
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/**
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* Fixed point maths class. This can be tailored for specific needs by
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* changing the bits allocated to the 'fraction' part (see <code>FIXED_POINT
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* </code>, which would also require <code>SIN_PRECALC</code> and <code>
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* COS_PRECALC</code> updating).
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*
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* <p><a href="http://blog.numfum.com/2007/09/java-fixed-point-maths.html">
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* http://blog.numfum.com/2007/09/java-fixed-point-maths.html</a></p>
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*
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* @version 1.0
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* @author CW
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*
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* @deprecated Most devices with OpenGL ES 2.0 have an FPU. Please use
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* floats instead of this class for decimal math.
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*/
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@Deprecated
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public final class Fixed {
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/**
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* Number of bits used for 'fraction'.
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*/
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public static final int FIXED_POINT = 16;
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/**
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* Decimal one as represented by the Fixed class.
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*/
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public static final int ONE = 1 << FIXED_POINT;
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/**
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* Half in fixed point.
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*/
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public static final int HALF = ONE >> 1;
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/**
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* Quarter circle resolution for trig functions (should be a power of
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* two). This is the number of discrete steps in 90 degrees.
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*/
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public static final int QUARTER_CIRCLE = 64;
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/**
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* Mask used to limit angles to one revolution. If a quarter circle is 64
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* (i.e. 90 degrees is broken into 64 steps) then the mask is 255.
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*/
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public static final int FULL_CIRCLE_MASK = QUARTER_CIRCLE * 4 - 1;
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/**
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* The trig table is generated at a higher precision than the typical
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* 16.16 format used for the rest of the fixed point maths. The table
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* values are then shifted to match the actual fixed point used.
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*/
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private static final int TABLE_SHIFT = 30;
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/**
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* Equivalent to: sin((2 * PI) / (QUARTER_CIRCLE * 4))
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* <p>
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* Note: if either QUARTER_CIRCLE or TABLE_SHIFT is changed this value
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* will need recalculating (put the above formular into a calculator set
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* radians, then shift the result by <code>TABLE_SHIFT</code>).
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*/
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private static final int SIN_PRECALC = 26350943;
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/**
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* Equivalent to: cos((2 * PI) / (QUARTER_CIRCLE * 4)) * 2
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*
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* Note: if either QUARTER_CIRCLE or TABLE_SHIFT is changed this value
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* will need recalculating ((put the above formular into a calculator set
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* radians, then shift the result by <code>TABLE_SHIFT</code>).
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*/
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private static final int COS_PRECALC = 2146836866;
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/**
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* One quarter sine wave as fixed point values.
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*/
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private static final int[] SINE_TABLE = new int[QUARTER_CIRCLE + 1];
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/**
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* Scale value for indexing ATAN_TABLE[].
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*/
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private static final int ATAN_SHIFT;
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/**
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* Reverse atan lookup table.
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*/
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private static final byte[] ATAN_TABLE;
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/**
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* ATAN_TABLE.length
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*/
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||||
private static final int ATAN_TABLE_LEN;
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/*
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* Generates the tables and fills in any remaining static ints.
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*/
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static {
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// Generate the sine table using recursive synthesis.
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SINE_TABLE[0] = 0;
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SINE_TABLE[1] = SIN_PRECALC;
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for (int n = 2; n < QUARTER_CIRCLE + 1; n++) {
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SINE_TABLE[n] = (int) (((long) SINE_TABLE[n - 1] * COS_PRECALC) >> TABLE_SHIFT) - SINE_TABLE[n - 2];
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}
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// Scale the values to the fixed point format used.
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for (int n = 0; n < QUARTER_CIRCLE + 1; n++) {
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SINE_TABLE[n] = SINE_TABLE[n] + (1 << (TABLE_SHIFT - FIXED_POINT - 1)) >> TABLE_SHIFT - FIXED_POINT;
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}
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// Calculate a shift used to scale atan lookups
|
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int rotl = 0;
|
||||
int tan0 = tan(0);
|
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int tan1 = tan(1);
|
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while (rotl < 32) {
|
||||
if ((tan1 >>= 1) > (tan0 >>= 1)) {
|
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rotl++;
|
||||
} else {
|
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break;
|
||||
}
|
||||
}
|
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ATAN_SHIFT = rotl;
|
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// Create the a table of tan values
|
||||
int[] lut = new int[QUARTER_CIRCLE];
|
||||
for (int n = 0; n < QUARTER_CIRCLE; n++) {
|
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lut[n] = tan(n) >> rotl;
|
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}
|
||||
ATAN_TABLE_LEN = lut[QUARTER_CIRCLE - 1];
|
||||
// Then from the tan values create a reverse lookup
|
||||
ATAN_TABLE = new byte[ATAN_TABLE_LEN];
|
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for (byte n = 0; n < QUARTER_CIRCLE - 1; n++) {
|
||||
int min = lut[n];
|
||||
int max = lut[n + 1];
|
||||
for (int i = min; i < max; i++) {
|
||||
ATAN_TABLE[i] = n;
|
||||
}
|
||||
}
|
||||
}
|
||||
/**
|
||||
* How many decimal places to use when converting a fixed point value to
|
||||
* a decimal string.
|
||||
*
|
||||
* @see #toString
|
||||
*/
|
||||
private static final int STRING_DECIMAL_PLACES = 2;
|
||||
/**
|
||||
* Value to add in order to round down a fixed point number when
|
||||
* converting to a string.
|
||||
*/
|
||||
private static final int STRING_DECIMAL_PLACES_ROUND;
|
||||
|
||||
static {
|
||||
int i = 10;
|
||||
for (int n = 1; n < STRING_DECIMAL_PLACES; n++) {
|
||||
i *= i;
|
||||
}
|
||||
if (STRING_DECIMAL_PLACES == 0) {
|
||||
STRING_DECIMAL_PLACES_ROUND = ONE / 2;
|
||||
} else {
|
||||
STRING_DECIMAL_PLACES_ROUND = ONE / (2 * i);
|
||||
}
|
||||
}
|
||||
/**
|
||||
* Random number generator. The standard <code>java.utll.Random</code> is
|
||||
* used since it is available to both J2ME and J2SE. If a guaranteed
|
||||
* sequence is required this would not be adequate.
|
||||
*/
|
||||
private static Random rng = null;
|
||||
|
||||
/**
|
||||
* Fixed can't be instantiated.
|
||||
*/
|
||||
private Fixed() {
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns an integer as a fixed point value.
|
||||
*/
|
||||
public static int intToFixed(int n) {
|
||||
return n << FIXED_POINT;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns a fixed point value as a float.
|
||||
*/
|
||||
public static float fixedToFloat(int i) {
|
||||
float fp = i;
|
||||
fp = fp / ((float) ONE);
|
||||
return fp;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns a float as a fixed point value.
|
||||
*/
|
||||
public static int floatToFixed(float fp) {
|
||||
return (int) (fp * ((float) ONE));
|
||||
}
|
||||
|
||||
/**
|
||||
* Converts a fixed point value into a decimal string.
|
||||
*/
|
||||
public static String toString(int n) {
|
||||
StringBuffer sb = new StringBuffer(16);
|
||||
sb.append((n += STRING_DECIMAL_PLACES_ROUND) >> FIXED_POINT);
|
||||
sb.append('.');
|
||||
n &= ONE - 1;
|
||||
for (int i = 0; i < STRING_DECIMAL_PLACES; i++) {
|
||||
n *= 10;
|
||||
sb.append((n / ONE) % 10);
|
||||
}
|
||||
return sb.toString();
|
||||
}
|
||||
|
||||
/**
|
||||
* Multiplies two fixed point values and returns the result.
|
||||
*/
|
||||
public static int mul(int a, int b) {
|
||||
return (int) ((long) a * (long) b >> FIXED_POINT);
|
||||
}
|
||||
|
||||
/**
|
||||
* Divides two fixed point values and returns the result.
|
||||
*/
|
||||
public static int div(int a, int b) {
|
||||
return (int) (((long) a << FIXED_POINT * 2) / (long) b >> FIXED_POINT);
|
||||
}
|
||||
|
||||
/**
|
||||
* Sine of an angle.
|
||||
*
|
||||
* @see #QUARTER_CIRCLE
|
||||
*/
|
||||
public static int sin(int n) {
|
||||
n &= FULL_CIRCLE_MASK;
|
||||
if (n < QUARTER_CIRCLE * 2) {
|
||||
if (n < QUARTER_CIRCLE) {
|
||||
return SINE_TABLE[n];
|
||||
} else {
|
||||
return SINE_TABLE[QUARTER_CIRCLE * 2 - n];
|
||||
}
|
||||
} else {
|
||||
if (n < QUARTER_CIRCLE * 3) {
|
||||
return -SINE_TABLE[n - QUARTER_CIRCLE * 2];
|
||||
} else {
|
||||
return -SINE_TABLE[QUARTER_CIRCLE * 4 - n];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Cosine of an angle.
|
||||
*
|
||||
* @see #QUARTER_CIRCLE
|
||||
*/
|
||||
public static int cos(int n) {
|
||||
n &= FULL_CIRCLE_MASK;
|
||||
if (n < QUARTER_CIRCLE * 2) {
|
||||
if (n < QUARTER_CIRCLE) {
|
||||
return SINE_TABLE[QUARTER_CIRCLE - n];
|
||||
} else {
|
||||
return -SINE_TABLE[n - QUARTER_CIRCLE];
|
||||
}
|
||||
} else {
|
||||
if (n < QUARTER_CIRCLE * 3) {
|
||||
return -SINE_TABLE[QUARTER_CIRCLE * 3 - n];
|
||||
} else {
|
||||
return SINE_TABLE[n - QUARTER_CIRCLE * 3];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Tangent of an angle.
|
||||
*
|
||||
* @see #QUARTER_CIRCLE
|
||||
*/
|
||||
public static int tan(int n) {
|
||||
return div(sin(n), cos(n));
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the arc tangent of an angle.
|
||||
*/
|
||||
public static int atan(int n) {
|
||||
n = n + (1 << (ATAN_SHIFT - 1)) >> ATAN_SHIFT;
|
||||
if (n < 0) {
|
||||
if (n <= -ATAN_TABLE_LEN) {
|
||||
return -(QUARTER_CIRCLE - 1);
|
||||
}
|
||||
return -ATAN_TABLE[-n];
|
||||
} else {
|
||||
if (n >= ATAN_TABLE_LEN) {
|
||||
return QUARTER_CIRCLE - 1;
|
||||
}
|
||||
return ATAN_TABLE[n];
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the polar angle of a rectangular coordinate.
|
||||
*/
|
||||
public static int atan(int x, int y) {
|
||||
int n = atan(div(x, abs(y) + 1)); // kludge to prevent ArithmeticException
|
||||
if (y > 0) {
|
||||
return n;
|
||||
}
|
||||
if (y < 0) {
|
||||
if (x < 0) {
|
||||
return -QUARTER_CIRCLE * 2 - n;
|
||||
}
|
||||
if (x > 0) {
|
||||
return QUARTER_CIRCLE * 2 - n;
|
||||
}
|
||||
return QUARTER_CIRCLE * 2;
|
||||
}
|
||||
if (x > 0) {
|
||||
return QUARTER_CIRCLE;
|
||||
}
|
||||
return -QUARTER_CIRCLE;
|
||||
}
|
||||
|
||||
/**
|
||||
* Rough calculation of the hypotenuse. Whilst not accurate it is very fast.
|
||||
* <p>
|
||||
* Derived from a piece in Graphics Gems.
|
||||
*/
|
||||
public static int hyp(int x1, int y1, int x2, int y2) {
|
||||
if ((x2 -= x1) < 0) {
|
||||
x2 = -x2;
|
||||
}
|
||||
if ((y2 -= y1) < 0) {
|
||||
y2 = -y2;
|
||||
}
|
||||
return x2 + y2 - (((x2 > y2) ? y2 : x2) >> 1);
|
||||
}
|
||||
|
||||
/**
|
||||
* Fixed point square root.
|
||||
* <p>
|
||||
* Derived from a 1993 Usenet algorithm posted by Christophe Meessen.
|
||||
*/
|
||||
public static int sqrt(int n) {
|
||||
if (n <= 0) {
|
||||
return 0;
|
||||
}
|
||||
long sum = 0;
|
||||
int bit = 0x40000000;
|
||||
while (bit >= 0x100) { // lower values give more accurate results
|
||||
long tmp = sum | bit;
|
||||
if (n >= tmp) {
|
||||
n -= tmp;
|
||||
sum = tmp + bit;
|
||||
}
|
||||
bit >>= 1;
|
||||
n <<= 1;
|
||||
}
|
||||
return (int) (sum >> 16 - (FIXED_POINT / 2));
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the absolute value.
|
||||
*/
|
||||
public static int abs(int n) {
|
||||
return (n < 0) ? -n : n;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the sign of a value, -1 for negative numbers, otherwise 1.
|
||||
*/
|
||||
public static int sgn(int n) {
|
||||
return (n < 0) ? -1 : 1;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the minimum of two values.
|
||||
*/
|
||||
public static int min(int a, int b) {
|
||||
return (a < b) ? a : b;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the maximum of two values.
|
||||
*/
|
||||
public static int max(int a, int b) {
|
||||
return (a > b) ? a : b;
|
||||
}
|
||||
|
||||
/**
|
||||
* Clamps the value n between min and max.
|
||||
*/
|
||||
public static int clamp(int n, int min, int max) {
|
||||
return (n < min) ? min : (n > max) ? max : n;
|
||||
}
|
||||
|
||||
/**
|
||||
* Wraps the value n between 0 and the required limit.
|
||||
*/
|
||||
public static int wrap(int n, int limit) {
|
||||
return ((n %= limit) < 0) ? limit + n : n;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the nearest int to a fixed point value. Equivalent to <code>
|
||||
* Math.round()</code> in the standard library.
|
||||
*/
|
||||
public static int round(int n) {
|
||||
return n + HALF >> FIXED_POINT;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the nearest int rounded down from a fixed point value.
|
||||
* Equivalent to <code>Math.floor()</code> in the standard library.
|
||||
*/
|
||||
public static int floor(int n) {
|
||||
return n >> FIXED_POINT;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the nearest int rounded up from a fixed point value.
|
||||
* Equivalent to <code>Math.ceil()</code> in the standard library.
|
||||
*/
|
||||
public static int ceil(int n) {
|
||||
return n + (ONE - 1) >> FIXED_POINT;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns a fixed point value greater than or equal to decimal 0.0 and
|
||||
* less than 1.0 (in 16.16 format this would be 0 to 65535 inclusive).
|
||||
*/
|
||||
public static int rand() {
|
||||
if (rng == null) {
|
||||
rng = new Random();
|
||||
}
|
||||
return rng.nextInt() >>> (32 - FIXED_POINT);
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns a random number between 0 and <code>n</code> (exclusive).
|
||||
*/
|
||||
public static int rand(int n) {
|
||||
return (rand() * n) >> FIXED_POINT;
|
||||
}
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user