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/*
* This file is part of SpongeAPI, licensed under the MIT License (MIT).
*
* Copyright (c) SpongePowered
* Copyright (c) contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.spongepowered.api.util.weighted;
import org.spongepowered.api.data.persistence.DataContainer;
import org.spongepowered.api.data.persistence.DataSerializable;
import org.spongepowered.api.data.persistence.Queries;
import org.spongepowered.math.GenericMath;
import java.util.Random;
import java.util.StringJoiner;
/**
* Represents a value which may vary randomly.
*
* Implementors of this interface using it in a fashion in which may ever be
* serialized must implement the {@link #toContainer()}
* method.
*/
@FunctionalInterface
public interface VariableAmount extends DataSerializable {
/**
* Creates a new 'fixed' variable amount, calls to {@link #amount} will
* always return the fixed value.
*
* @param value The fixed value
* @return A variable amount representation
*/
static VariableAmount fixed(final double value) {
return new Fixed(value);
}
/**
* Creates a new variable amount which return values between the given min
* (inclusive) and max (exclusive).
*
* @param min The minimum of the range (inclusive)
* @param max The maximum of the range (exclusive)
* @return A variable amount representation
*/
static VariableAmount range(final double min, final double max) {
return new BaseAndAddition(min, VariableAmount.fixed(max - min));
}
/**
* Creates a new variable about which has a base and variance. The final
* amount will be the base amount plus or minus a random amount between zero
* (inclusive) and the variance (exclusive).
*
* @param base The base value
* @param variance The variance
* @return A variable amount representation
*/
static VariableAmount baseWithVariance(final double base, final double variance) {
return new BaseAndVariance(base, VariableAmount.fixed(variance));
}
/**
* Creates a new variable about which has a base and variance. The final
* amount will be the base amount plus or minus a random amount between zero
* (inclusive) and the variance (exclusive).
*
* @param base The base value
* @param variance The variance
* @return A variable amount representation
*/
static VariableAmount baseWithVariance(final double base, final VariableAmount variance) {
return new BaseAndVariance(base, variance);
}
/**
* Creates a new variable amount which has a base and an additional amount.
* The final amount will be the base amount plus a random amount between
* zero (inclusive) and the additional amount (exclusive).
*
* @param base The base value
* @param addition The additional amount
* @return A variable amount representation
*/
static VariableAmount baseWithRandomAddition(final double base, final double addition) {
return new BaseAndAddition(base, VariableAmount.fixed(addition));
}
/**
* Creates a new variable amount which has a base and an additional amount.
* The final amount will be the base amount plus a random amount between
* zero (inclusive) and the additional amount (exclusive).
*
* @param base The base value
* @param addition The additional amount
* @return A variable amount representation
*/
static VariableAmount baseWithRandomAddition(final double base, final VariableAmount addition) {
return new BaseAndAddition(base, addition);
}
/**
* Creates a new variable about which has a base and a chance to apply a
* random variance. The chance should be between zero and one with a chance
* of one signifying that the variance will always be applied. If the chance
* succeeds then the final amount will be the base amount plus or minus a
* random amount between zero (inclusive) and the variance (exclusive). If
* the chance fails then the final amount will just be the base value.
*
* @param base The base value
* @param variance The variance
* @param chance The chance to apply the variance
* @return A variable amount representation
*/
static VariableAmount baseWithOptionalVariance(final double base, final double variance, final double chance) {
return new OptionalAmount(base, chance, VariableAmount.baseWithVariance(base, variance));
}
/**
* Creates a new variable about which has a base and a chance to apply a
* random variance. The chance should be between zero and one with a chance
* of one signifying that the variance will always be applied. If the chance
* succeeds then the final amount will be the base amount plus or minus a
* random amount between zero (inclusive) and the variance (exclusive). If
* the chance fails then the final amount will just be the base value.
*
* @param base The base value
* @param variance The variance
* @param chance The chance to apply the variance
* @return A variable amount representation
*/
static VariableAmount baseWithOptionalVariance(final double base, final VariableAmount variance, final double chance) {
return new OptionalAmount(base, chance, VariableAmount.baseWithVariance(base, variance));
}
/**
* Creates a new variable about which has a base and a chance to apply a
* random additional amount. The chance should be between zero and one with
* a chance of one signifying that the additional amount will always be
* applied. If the chance succeeds then the final amount will be the base
* amount plus a random amount between zero (inclusive) and the additional
* amount (exclusive). If the chance fails then the final amount will just
* be the base value.
*
* @param base The base value
* @param addition The additional amount
* @param chance The chance to apply the additional amount
* @return A variable amount representation
*/
static VariableAmount baseWithOptionalAddition(final double base, final double addition, final double chance) {
return new OptionalAmount(base, chance, VariableAmount.baseWithRandomAddition(base, addition));
}
/**
* Creates a new variable about which has a base and a chance to apply a
* random additional amount. The chance should be between zero and one with
* a chance of one signifying that the additional amount will always be
* applied. If the chance succeeds then the final amount will be the base
* amount plus a random amount between zero (inclusive) and the additional
* amount (exclusive). If the chance fails then the final amount will just
* be the base value.
*
* @param base The base value
* @param addition The additional amount
* @param chance The chance to apply the additional amount
* @return A variable amount representation
*/
static VariableAmount baseWithOptionalAddition(final double base, final VariableAmount addition, final double chance) {
return new OptionalAmount(base, chance, VariableAmount.baseWithRandomAddition(base, addition));
}
/**
* Gets an instance of the variable amount depending on the given random
* object.
*
* @param rand The random object
* @return The amount
*/
double amount(Random rand);
/**
* Gets the amount as if from {@link #amount(Random)} but floored to the
* nearest integer equivalent.
*
* @param rand The random object
* @return The floored amount
*/
default int flooredAmount(final Random rand) {
return GenericMath.floor(this.amount(rand));
}
// This is overridden to allow this to be a functional interface as this
// greatly increases the usability of the interface.
@Override
default DataContainer toContainer() {
throw new UnsupportedOperationException();
}
@Override
default int contentVersion() {
return 0;
}
/**
* Represents a fixed amount, calls to {@link #amount} will always return
* the same fixed value.
*/
class Fixed implements VariableAmount {
private final double amount;
Fixed(final double amount) {
this.amount = amount;
}
@Override
public double amount(final Random rand) {
return this.amount;
}
@Override
public String toString() {
return new StringJoiner(", ", Fixed.class.getSimpleName() + "[", "]")
.add("amount=" + this.amount)
.toString();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof Fixed)) {
return false;
}
final Fixed amount = (Fixed) obj;
return amount.amount == this.amount;
}
@Override
public int hashCode() {
int result = 1;
result = 37 * result + (int) (Double.doubleToLongBits(this.amount) ^ (Double.doubleToLongBits(this.amount) >> 32));
return result;
}
@Override
public DataContainer toContainer() {
return DataContainer.createNew()
.set(Queries.CONTENT_VERSION, this.contentVersion())
.set(Queries.VARIABLE_AMOUNT, this.amount);
}
@Override
public int contentVersion() {
return 1;
}
}
/**
* Represents a base amount with a variance, the final amount will be the
* base amount plus or minus a random amount between zero (inclusive) and
* the variance (exclusive).
*/
class BaseAndVariance implements VariableAmount {
private final double base;
private final VariableAmount variance;
BaseAndVariance(final double base, final VariableAmount variance) {
this.base = base;
this.variance = variance;
}
@Override
public double amount(final Random rand) {
final double var = this.variance.amount(rand);
return this.base + rand.nextDouble() * var * 2 - var;
}
@Override
public String toString() {
return new StringJoiner(", ", BaseAndVariance.class.getSimpleName() + "[", "]")
.add("base=" + this.base)
.add("variance=" + this.variance)
.toString();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof BaseAndVariance)) {
return false;
}
final BaseAndVariance amount = (BaseAndVariance) obj;
return amount.base == this.base && amount.variance == this.variance;
}
@Override
public int hashCode() {
int result = 1;
result = 37 * result + (int) (Double.doubleToLongBits(this.base) ^ (Double.doubleToLongBits(this.base) >> 32));
result = 37 * result + this.variance.hashCode();
return result;
}
@Override
public DataContainer toContainer() {
return DataContainer.createNew()
.set(Queries.CONTENT_VERSION, this.contentVersion())
.set(Queries.VARIABLE_BASE, this.base)
.set(Queries.VARIABLE_VARIANCE, this.variance);
}
@Override
public int contentVersion() {
return 1;
}
}
/**
* Represents a base amount with a random addition, the final amount will be
* the base amount plus a random amount between zero (inclusive) and the
* addition (exclusive).
*/
class BaseAndAddition implements VariableAmount {
private final double base;
private final VariableAmount addition;
BaseAndAddition(final double base, final VariableAmount addition) {
this.base = base;
this.addition = addition;
}
@Override
public double amount(final Random rand) {
return this.base + (rand.nextDouble() * this.addition.amount(rand));
}
@Override
public String toString() {
return new StringJoiner(", ", BaseAndAddition.class.getSimpleName() + "[", "]")
.add("base=" + this.base)
.add("addition=" + this.addition)
.toString();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof BaseAndAddition)) {
return false;
}
final BaseAndAddition amount = (BaseAndAddition) obj;
return amount.base == this.base && amount.addition == this.addition;
}
@Override
public int hashCode() {
int result = 1;
result = 37 * result + (int) (Double.doubleToLongBits(this.base) ^ (Double.doubleToLongBits(this.base) >> 32));
result = 37 * result + this.addition.hashCode();
return result;
}
@Override
public DataContainer toContainer() {
return DataContainer.createNew()
.set(Queries.CONTENT_VERSION, this.contentVersion())
.set(Queries.VARIABLE_BASE, this.base)
.set(Queries.VARIABLE_VARIANCE, this.addition);
}
@Override
public int contentVersion() {
return 1;
}
}
/**
* Represents a variable amount which has a base and a chance of varying.
* This wraps another {@link VariableAmount} which it refers to if the
* chance succeeds.
*/
class OptionalAmount implements VariableAmount {
private final double chance;
private final double base;
private final VariableAmount inner;
OptionalAmount(final double base, final double chance, final VariableAmount inner) {
this.base = base;
this.inner = inner;
this.chance = chance;
}
@Override
public double amount(final Random rand) {
if (rand.nextDouble() < this.chance) {
return this.inner.amount(rand);
}
return this.base;
}
@Override
public String toString() {
return new StringJoiner(
", ",
OptionalAmount.class.getSimpleName() + "[",
"]"
)
.add("chance=" + this.chance)
.add("base=" + this.base)
.add("inner=" + this.inner)
.toString();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof OptionalAmount)) {
return false;
}
final OptionalAmount amount = (OptionalAmount) obj;
return this.inner.equals(amount.inner) && amount.base == this.base && this.chance == amount.chance;
}
@Override
public int hashCode() {
int result = 1;
result = 37 * result + (int) (Double.doubleToLongBits(this.base) ^ (Double.doubleToLongBits(this.base) >> 32));
result = 37 * result + (int) (Double.doubleToLongBits(this.chance) ^ (Double.doubleToLongBits(this.chance) >> 32));
result = 37 * result + this.inner.hashCode();
return result;
}
@Override
public DataContainer toContainer() {
return DataContainer.createNew()
.set(Queries.CONTENT_VERSION, this.contentVersion())
.set(Queries.VARIABLE_CHANCE, this.chance)
.set(Queries.VARIABLE_BASE, this.base)
.set(Queries.VARIABLE_VARIANCE, this.inner);
}
@Override
public int contentVersion() {
return 1;
}
}
}