/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

/* $Id: PDFFunction.java 1785982 2017-03-08 15:15:06Z ssteiner $ */

package org.apache.fop.pdf;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.apache.fop.render.gradient.Function;
import org.apache.fop.render.gradient.Function.SubFunctionRenderer;
import org.apache.fop.render.gradient.GradientMaker;
import org.apache.fop.render.gradient.GradientMaker.DoubleFormatter;

class representing a PDF Function.
PDF Functions represent parameterized mathematical formulas and
sampled representations with
arbitrary resolution. Functions are used in two areas: device-dependent
rasterization information for halftoning and transfer
functions, and color specification for smooth shading (a PDF 1.3 feature).
All PDF Functions have a FunctionType (0,2,3, or 4), a Domain, and a Range.
/**
 * class representing a PDF Function.
 *
 * PDF Functions represent parameterized mathematical formulas and
 * sampled representations with
 * arbitrary resolution. Functions are used in two areas: device-dependent
 * rasterization information for halftoning and transfer
 * functions, and color specification for smooth shading (a PDF 1.3 feature).
 *
 * All PDF Functions have a FunctionType (0,2,3, or 4), a Domain, and a Range.
 */
public class PDFFunction extends PDFObject {

    private final Function function;

    private final List<PDFFunction> pdfFunctions;

    
create an complete Function object of Type 2, an Exponential Interpolation function.
Use null for an optional object parameter if you choose not to use it.
For optional int parameters, pass the default.
Params:
domain – List objects of Double objects.
This is the domain of the function.
See page 264 of the PDF 1.3 Spec.
range – List of Doubles that is the Range of the function.
See page 264 of the PDF 1.3 Spec.
cZero – This is a vector of Double objects which defines the function result
when x=0.
This attribute is optional.
It's described on page 268 of the PDF 1.3 spec.
cOne – This is a vector of Double objects which defines the function result
when x=1.
This attribute is optional.
It's described on page 268 of the PDF 1.3 spec.
interpolationExponentN – This is the inerpolation exponent.
This attribute is required.
PDF Spec page 268/**
     * create an complete Function object of Type 2, an Exponential Interpolation function.
     *
     * Use null for an optional object parameter if you choose not to use it.
     * For optional int parameters, pass the default.
     *
     * @param domain List objects of Double objects.
     * This is the domain of the function.
     * See page 264 of the PDF 1.3 Spec.
     * @param range List of Doubles that is the Range of the function.
     * See page 264 of the PDF 1.3 Spec.
     * @param cZero This is a vector of Double objects which defines the function result
     * when x=0.
     *
     * This attribute is optional.
     * It's described on page 268 of the PDF 1.3 spec.
     * @param cOne This is a vector of Double objects which defines the function result
     * when x=1.
     *
     * This attribute is optional.
     * It's described on page 268 of the PDF 1.3 spec.
     * @param interpolationExponentN This is the inerpolation exponent.
     *
     * This attribute is required.
     * PDF Spec page 268
     */
    public PDFFunction(List<Double> domain, List<Double> range, float[] cZero, float[] cOne,
            double interpolationExponentN) {
        this(new Function(domain, range, cZero, cOne, interpolationExponentN));

    }

    @SuppressWarnings("unchecked")
    public PDFFunction(Function function) {
        this(function, Collections.EMPTY_LIST);
    }

    public PDFFunction(Function function, List<PDFFunction> pdfFunctions) {
        this.function = function;
        this.pdfFunctions = pdfFunctions;
    }

    public Function getFunction() {
        return function;
    }

    
represent as PDF. Whatever the FunctionType is, the correct
representation spits out. The sets of required and optional
attributes are different for each type, but if a required
attribute's object was constructed as null, then no error
is raised. Instead, the malformed PDF that was requested
by the construction is dutifully output.
This policy should be reviewed.
Returns:
the PDF string./**
     * represent as PDF. Whatever the FunctionType is, the correct
     * representation spits out. The sets of required and optional
     * attributes are different for each type, but if a required
     * attribute's object was constructed as null, then no error
     * is raised. Instead, the malformed PDF that was requested
     * by the construction is dutifully output.
     * This policy should be reviewed.
     *
     * @return the PDF string.
     */
    public byte[] toPDF() {
        return toByteString();
    }


    public byte[] toByteString() {
        SubFunctionRenderer subFunctionRenderer = new SubFunctionRenderer() {

            public void outputFunction(StringBuilder out, int functionIndex) {
                out.append(pdfFunctions.get(functionIndex).referencePDF());
            }
        };
        StringBuilder out = new StringBuilder();
        GradientMaker.DoubleFormatter doubleFormatter = new DoubleFormatter() {

            public String formatDouble(double d) {
                return PDFNumber.doubleOut(d);
            }
        };
        function.output(out, doubleFormatter, subFunctionRenderer);
        return encode(out.toString());
    }

    
{@inheritDoc} /** {@inheritDoc} */
    protected boolean contentEquals(PDFObject obj) {
        if (obj == null) {
            return false;
        }
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof PDFFunction)) {
            return false;
        }
        Function func = ((PDFFunction) obj).function;
        if (function.getFunctionType() != func.getFunctionType()) {
            return false;
        }
        if (function.getBitsPerSample() != func.getBitsPerSample()) {
            return false;
        }
        if (function.getOrder() != func.getOrder()) {
            return false;
        }
        if (function.getInterpolationExponentN() != func.getInterpolationExponentN()) {
            return false;
        }
        if (function.getDomain() != null) {
            if (!function.getDomain().equals(func.getDomain())) {
                return false;
            }
        } else if (func.getDomain() != null) {
            return false;
        }
        if (function.getRange() != null) {
            if (!function.getRange().equals(func.getRange())) {
                return false;
            }
        } else if (func.getRange() != null) {
            return false;
        }
        if (function.getEncode() != null) {
            if (!function.getEncode().equals(func.getEncode())) {
                return false;
            }
        } else if (func.getEncode() != null) {
            return false;
        }
        if (!Arrays.equals(function.getCZero(), func.getCZero())) {
            return false;
        }
        if (!Arrays.equals(function.getCOne(), func.getCOne())) {
            return false;
        }
        if (!pdfFunctions.equals(((PDFFunction) obj).pdfFunctions)) {
            return false;
        }
        if (function.getBounds() != null) {
            if (!function.getBounds().equals(func.getBounds())) {
                return false;
            }
        } else if (func.getBounds() != null) {
            return false;
        }
        return true;
    }

}