# PDFunctionTypeIdentity.java

    /*
     * Copyright 2014 The Apache Software Foundation.
     *
     * 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 org.apache.pdfbox.pdmodel.common.function;

    import java.io.IOException;

    import org.apache.pdfbox.cos.COSArray;
    import org.apache.pdfbox.cos.COSBase;

    /**
     * The identity function.
     *
     * @author Tilman Hausherr
     */
    public class PDFunctionTypeIdentity extends PDFunction
    {

        public PDFunctionTypeIdentity(COSBase function)
        {
            super(null);
            //TODO passing null is not good because getCOSObject() can result in an NPE in the base class
        }

        @Override
        public int getFunctionType()
        {
            // shouldn't be called
            throw new UnsupportedOperationException();
            //TODO this is a violation of the interface segregation principle
        }

        @Override
        public float[] eval(float[] input) throws IOException
        {
            return input;
        }

        @Override
        protected COSArray getRangeValues()
        {
            return null;
        }

        /**
         * {@inheritDoc}
         */
        @Override
        public String toString()
        {
            return "FunctionTypeIdentity";
        }

    }