commonMain.com.sudoplay.joise.noise.Util.kt Maven / Gradle / Ivy

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/*
 * Copyright (C) 2013 Jason Taylor.
 * Released as open-source under the Apache License, Version 2.0.
 *
 * ============================================================================
 * | Joise
 * ============================================================================
 *
 * Copyright (C) 2013 Jason Taylor
 *
 * 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.
 *
 * ============================================================================
 * | Accidental Noise Library
 * | --------------------------------------------------------------------------
 * | Joise is a derivative work based on Josua Tippetts' C++ library:
 * | http://accidentalnoise.sourceforge.net/index.html
 * ============================================================================
 *
 * Copyright (C) 2011 Joshua Tippetts
 *
 *   This software is provided 'as-is', without any express or implied
 *   warranty.  In no event will the authors be held liable for any damages
 *   arising from the use of this software.
 *
 *   Permission is granted to anyone to use this software for any purpose,
 *   including commercial applications, and to alter it and redistribute it
 *   freely, subject to the following restrictions:
 *
 *   1. The origin of this software must not be misrepresented; you must not
 *      claim that you wrote the original software. If you use this software
 *      in a product, an acknowledgment in the product documentation would be
 *      appreciated but is not required.
 *   2. Altered source versions must be plainly marked as such, and must not be
 *      misrepresented as being the original software.
 *   3. This notice may not be removed or altered from any source distribution.
 */
package com.sudoplay.joise.noise

import kotlin.jvm.JvmOverloads
import kotlin.jvm.JvmStatic
import kotlin.math.PI
import kotlin.math.floor
import kotlin.math.ln
import kotlin.math.pow

@Suppress("MagicNumber")
object Util {

    const val TWO_PI = PI * 2.0
    private val INV_LOG_HALF = 1.0 / ln(0.5)

    @JvmStatic
    fun clamp(input: Double, min: Double, max: Double): Double =
        if (input < min) min else if (input > max) max else input

    @JvmStatic
    fun bias(b: Double, t: Double): Double = t.pow(ln(b) * INV_LOG_HALF)

    @JvmStatic
    fun lerp(t: Double, a: Double, b: Double): Double = a + t * (b - a)

    @JvmStatic
    fun gain(g: Double, t: Double): Double {
        val g1 = clamp(g, 0.0, 1.0)
        return if (t < 0.5) {
            bias(1.0 - g1, 2.0 * t) * 0.5
        } else {
            1.0 - bias(1.0 - g1, 2.0 - 2.0 * t) * 0.5
        }
    }

    @JvmStatic
    fun quinticBlend(t: Double): Double = t * t * t * (t * (t * 6 - 15) + 10)

    @JvmStatic
    fun sawtooth(x: Double, p: Double): Double = 2.0 * (x / p - floor(0.5 + x / p)) * 0.5 + 0.5

    class Vector3d @JvmOverloads constructor(var x: Double = 0.0, var y: Double = 0.0, var z: Double = 0.0)

}