dorkbox.util.MathUtil.kt Maven / Gradle / Ivy
/*
* Copyright 2023 dorkbox, llc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dorkbox.util
object MathUtil {
/**
* Checks to see if the string is an integer
*
* @return true if it's an integer, false otherwise
*/
fun isInteger(string: String): Boolean {
return isNumber(string, 10)
}
/**
* Checks to see if the string is a long
*
* @return true if it's a long, false otherwise
*/
fun isLong(string: String): Boolean {
return isNumber(string, 19)
}
/**
* Checks to see if the character is a number
*
* @return true if it's a number, false otherwise
*/
fun isNumber(character: Char): Boolean {
// way faster than Character.isDigit()
return character >= '0' && character <= '9'
}
/**
* Checks to see if the string is a number
*
* @return true if it's a number, false otherwise
*/
fun isNumber(string: String, sizeLimit: Long): Boolean {
if (sizeLimit <= 0) {
return false
}
val length = string.length
if (length == 0) {
return false
}
var i = 0
if (string[0] == '-') {
if (length == 1) {
return false
}
i = 1
}
if (length - i > sizeLimit) {
return false
}
while (i < length) {
val c = string[i]
// way faster than Character.isDigit()
if (c < '0' || c > '9') {
return false
}
i++
}
return true
}
/**
* Gets the number of digits represented by the specified number
*
* @param number the number to check, negative numbers are also acceptable but the sign is not counted
*
* @return the number of digits of the number, from 1-19.
*/
fun numberOfDigits(number: Long): Int {
// have to make it always positive for the following checks to pass.
var number = number
if (number < 0L) {
number = -number
}
// Guessing 4 digit numbers will be more probable.
// They are set in the first branch.
return if (number < 10000L) { // from 1 to 4
if (number < 100L) { // 1 or 2
if (number < 10L) {
1
} else {
2
}
} else { // 3 or 4
if (number < 1000L) {
3
} else {
4
}
}
} else { // from 5 to 20 (albeit longs can't have more than 18 or 19)
if (number < 1000000000000L) { // from 5 to 12
if (number < 100000000L) { // from 5 to 8
if (number < 1000000L) { // 5 or 6
if (number < 100000L) {
5
} else {
6
}
} else { // 7 u 8
if (number < 10000000L) {
7
} else {
8
}
}
} else { // from 9 to 12
if (number < 10000000000L) { // 9 or 10
if (number < 1000000000L) {
9
} else {
10
}
} else { // 11 or 12
if (number < 100000000000L) {
11
} else {
12
}
}
}
} else { // from 13 to ... (18 or 20)
if (number < 10000000000000000L) { // from 13 to 16
if (number < 100000000000000L) { // 13 or 14
if (number < 10000000000000L) {
13
} else {
14
}
} else { // 15 or 16
if (number < 1000000000000000L) {
15
} else {
16
}
}
} else { // from 17 to ... 20?
if (number < 1000000000000000000L) { // 17 or 18
if (number < 100000000000000000L) {
17
} else {
18
}
} else { // 19? Can it be?
// 10000000000000000000L isn't a valid long.
19
}
}
}
}
}
/**
* Removes any characters from the end that are not a number
*
* @param text the input text that may, or may not, contain a mix of numbers and letters
* @return the value as an integer
*/
fun stripTrailingNonDigits(text: String): Int {
if (text.isEmpty()) {
return 0
}
var numberIndex = 0
val length = text.length
while (numberIndex < length && Character.isDigit(text[numberIndex])) {
numberIndex++
}
val substring = text.substring(0, numberIndex)
try {
return substring.toInt()
} catch (ignored: Exception) {
}
return 0
}
fun isEven(value: Int): Boolean {
return value and 1 == 0
}
/**
* Returns the next power of two. Returns the specified value if the value is already a power of two.
*/
fun nextPowerOfTwo(value: Int): Int {
return 1 shl 32 - Integer.numberOfLeadingZeros(value - 1)
}
fun isPowerOfTwo(value: Int): Boolean {
return value != 0 && value and value - 1 == 0
}
fun intersectRect(x1: Double, y1: Double, w1: Double, h1: Double, x2: Double, y2: Double, w2: Double, h2: Double): Boolean {
return intersectRange(x1, x1 + w1, x2, x2 + w2) && intersectRange(y1, y1 + h1, y2, y2 + h2)
}
fun intersectRange(ax1: Double, ax2: Double, bx1: Double, bx2: Double): Boolean {
return Math.max(ax1, bx1) <= Math.min(ax2, bx2)
}
/**
* Clamps a value to min/max values, where it cannot exceed either.
*
* @return the new value, clamped
*/
fun clamp(value: Int, min: Int, max: Int): Int {
return Math.max(min, Math.min(max, value))
}
/**
* Clamps a value to min/max values, where it cannot exceed either.
*
* @return the new value, clamped
*/
fun clamp(value: Long, min: Long, max: Long): Long {
return Math.max(min, Math.min(max, value))
}
/**
* Clamps a value to min/max values, where it cannot exceed either.
*
* @return the new value, clamped
*/
fun clamp(value: Float, min: Float, max: Float): Float {
return Math.max(min, Math.min(max, value))
}
/**
* Clamps a value to min/max values, where it cannot exceed either.
*
* @return the new value, clamped
*/
fun clamp(value: Double, min: Double, max: Double): Double {
return Math.max(min, Math.min(max, value))
}
}
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