/
MathUtil.kt
43 lines (35 loc) · 1.4 KB
/
MathUtil.kt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
/*
* Copyright 2014 Google Inc.
*
* 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 com.google.android.apps.muzei.util
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min
fun Float.constrain(min: Float, max: Float): Float = max(min, min(max, this))
fun interpolate(x1: Float, x2: Float, f: Float): Float = x1 + (x2 - x1) * f
fun uninterpolate(x1: Float, x2: Float, v: Float): Float {
if (x2 - x1 == 0f) {
throw IllegalArgumentException("Can't reverse interpolate with domain size of 0")
}
return (v - x1) / (x2 - x1)
}
fun Int.floorEven() = this and 0x01.inv()
fun Int.roundMult4() = this + 2 and 0x03.inv()
// divide two integers but round up
// see http://stackoverflow.com/a/7446742/102703
fun Int.divideRoundUp(divisor: Int): Int {
val sign = (if (this > 0) 1 else -1) * if (divisor > 0) 1 else -1
return sign * (abs(this) + abs(divisor) - 1) / abs(divisor)
}