com.badlogic.gdx.graphics.g3d.Attribute.java Source code

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Here is the source code for com.badlogic.gdx.graphics.g3d.Attribute.java

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/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * 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.badlogic.gdx.graphics.g3d;

import com.badlogic.gdx.utils.Array;

/** Extend this class to implement a material attribute. Register the attribute type by statically calling the
 * {@link #register(String)} method, whose return value should be used to instantiate the attribute. A class can implement
 * multiple types
 * @author Xoppa */
public abstract class Attribute {
    /** The registered type aliases */
    private final static Array<String> types = new Array<String>();

    /** @return The ID of the specified attribute type, or zero if not available */
    public final static long getAttributeType(final String alias) {
        for (int i = 0; i < types.size; i++)
            if (types.get(i).compareTo(alias) == 0)
                return 1L << i;
        return 0;
    }

    /** @return The alias of the specified attribute type, or null if not available. */
    public final static String getAttributeAlias(final long type) {
        int idx = -1;
        while (type != 0 && ++idx < 63 && (((type >> idx) & 1) == 0))
            ;
        return (idx >= 0 && idx < types.size) ? types.get(idx) : null;
    }

    /** Use {@link Attribute#register(String)} instead */
    protected final static long register(final String alias) {
        long result = getAttributeType(alias);
        if (result > 0)
            return result;
        types.add(alias);
        return 1L << (types.size - 1);
    }

    /** The type of this attribute */
    public final long type;

    private final int typeBit;

    protected Attribute(final long type) {
        this.type = type;
        this.typeBit = Long.numberOfTrailingZeros(type);
    }

    /** @return An exact copy of this attribute */
    public abstract Attribute copy();

    protected boolean equals(Attribute other) {
        return other.hashCode() == hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null)
            return false;
        if (obj == this)
            return true;
        if (!(obj instanceof Attribute))
            return false;
        final Attribute other = (Attribute) obj;
        if (this.type != other.type)
            return false;
        return equals(other);
    }

    @Override
    public String toString() {
        return getAttributeAlias(type);
    }

    @Override
    public int hashCode() {
        return 7489 * typeBit;
    }
}