/* * Copyright 1999-2004 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. */ /* $Id$ */ package org.apache.fop.pdf; // Java... import java.util.List; /** * 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 { // Guts common to all function types /** * Required: The Type of function (0,2,3,4) default is 0. */ protected int functionType = 0; // Default /** * Required: 2 * m Array of Double numbers which are possible inputs to the function */ protected List domain = null; /** * Required: 2 * n Array of Double numbers which are possible outputs to the function */ protected List range = null; /* ********************TYPE 0***************************** */ // FunctionType 0 specific function guts /** * Required: Array containing the Integer size of the Domain and Range, respectively. * Note: This is really more like two seperate integers, sizeDomain, and sizeRange, * but since they're expressed as an array in PDF, my implementation reflects that. */ protected List size = null; /** * Required for Type 0: Number of Bits used to represent each sample value. * Limited to 1,2,4,8,12,16,24, or 32 */ protected int bitsPerSample = 1; /** * Optional for Type 0: order of interpolation between samples. * Limited to linear (1) or cubic (3). Default is 1 */ protected int order = 1; /** * Optional for Type 0: A 2 * m array of Doubles which provides a * linear mapping of input values to the domain. * * Required for Type 3: A 2 * k array of Doubles that, taken * in pairs, map each subset of the domain defined by Domain * and the Bounds array to the domain of the corresponding function. * Should be two values per function, usually (0,1), * as in [0 1 0 1] for 2 functions. */ protected List encode = null; /** * Optional for Type 0: A 2 * n array of Doubles which provides * a linear mapping of sample values to the range. Defaults to Range. */ protected List decode = null; /** * Optional For Type 0: A stream of sample values */ /** * Required For Type 4: Postscript Calculator function * composed of arithmetic, boolean, and stack operators + boolean constants */ protected StringBuffer functionDataStream = null; /** * Required (possibly) For Type 0: A vector of Strings for the * various filters to be used to decode the stream. * These are how the string is compressed. Flate, LZW, etc. */ protected List filter = null; /* *************************TYPE 2************************** */ /** * Required For Type 2: An Array of n Doubles defining * the function result when x=0. Default is [0]. */ protected List cZero = null; /** * Required For Type 2: An Array of n Doubles defining * the function result when x=1. Default is [1]. */ protected List cOne = null; /** * Required for Type 2: The interpolation exponent. * Each value x will return n results. * Must be greater than 0. */ protected double interpolationExponentN = 1; /* *************************TYPE 3************************** */ /** * Required for Type 3: An vector of PDFFunctions which * form an array of k single input functions making up * the stitching function. */ protected List functions = null; /** * Optional for Type 3: An array of (k-1) Doubles that, * in combination with Domain, define the intervals to which * each function from the Functions array apply. Bounds * elements must be in order of increasing magnitude, * and each value must be within the value of Domain. * k is the number of functions. * If you pass null, it will output (1/k) in an array of k-1 elements. * This makes each function responsible for an equal amount of the stitching function. * It makes the gradient even. */ protected List bounds = null; // See encode above, as it's also part of Type 3 Functions. /* *************************TYPE 4************************** */ // See 'data' above. /** * create an complete Function object of Type 0, A Sampled function. * * Use null for an optional object parameter if you choose not to use it. * For optional int parameters, pass the default. * * @param theDomain List objects of Double objects. * This is the domain of the function. * See page 264 of the PDF 1.3 Spec. * @param theRange List objects of Double objects. * This is the Range of the function. * See page 264 of the PDF 1.3 Spec. * @param theSize A List object of Integer objects. * This is the number of samples in each input dimension. * I can't imagine there being more or less than two input dimensions, * so maybe this should be an array of length 2. * * See page 265 of the PDF 1.3 Spec. * @param theBitsPerSample An int specifying the number of bits used to represent each sample value. * Limited to 1,2,4,8,12,16,24 or 32. * See page 265 of the 1.3 PDF Spec. * @param theOrder The order of interpolation between samples. Default is 1 (one). Limited * to 1 (one) or 3, which means linear or cubic-spline interpolation. * * This attribute is optional. * * See page 265 in the PDF 1.3 spec. * @param theEncode List objects of Double objects. * This is the linear mapping of input values intop the domain * of the function's sample table. Default is hard to represent in * ascii, but basically [0 (Size0 1) 0 (Size1 1)...]. * This attribute is optional. * * See page 265 in the PDF 1.3 spec. * @param theDecode List objects of Double objects. * This is a linear mapping of sample values into the range. * The default is just the range. * * This attribute is optional. * Read about it on page 265 of the PDF 1.3 spec. * @param theFunctionDataStream The sample values that specify * the function are provided in a stream. * * This is optional, but is almost always used. * * Page 265 of the PDF 1.3 spec has more. * @param theFilter This is a vector of String objects which are the various filters that * have are to be applied to the stream to make sense of it. Order matters, * so watch out. * * This is not documented in the Function section of the PDF 1.3 spec, * it was deduced from samples that this is sometimes used, even if we may never * use it in FOP. It is added for completeness sake. * @param theFunctionType This is the type of function (0,2,3, or 4). * It should be 0 as this is the constructor for sampled functions. */ public PDFFunction(int theFunctionType, List theDomain, List theRange, List theSize, int theBitsPerSample, int theOrder, List theEncode, List theDecode, StringBuffer theFunctionDataStream, List theFilter) { super(); this.functionType = 0; // dang well better be 0; this.size = theSize; this.bitsPerSample = theBitsPerSample; this.order = theOrder; // int this.encode = theEncode; // vector of int this.decode = theDecode; // vector of int this.functionDataStream = theFunctionDataStream; this.filter = theFilter; // vector of Strings // the domain and range are actually two dimensional arrays. // so if there's not an even number of items, bad stuff // happens. this.domain = theDomain; this.range = theRange; } /** * 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 theDomain List objects of Double objects. * This is the domain of the function. * See page 264 of the PDF 1.3 Spec. * @param theRange List of Doubles that is the Range of the function. * See page 264 of the PDF 1.3 Spec. * @param theCZero 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 theCOne 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 theInterpolationExponentN This is the inerpolation exponent. * * This attribute is required. * PDF Spec page 268 * @param theFunctionType The type of the function, which should be 2. */ public PDFFunction(int theFunctionType, List theDomain, List theRange, List theCZero, List theCOne, double theInterpolationExponentN) { super(); this.functionType = 2; // dang well better be 2; this.cZero = theCZero; this.cOne = theCOne; this.interpolationExponentN = theInterpolationExponentN; this.domain = theDomain; this.range = theRange; } /** * create an complete Function object of Type 3, a Stitching function. * * Use null for an optional object parameter if you choose not to use it. * For optional int parameters, pass the default. * * @param theDomain List objects of Double objects. * This is the domain of the function. * See page 264 of the PDF 1.3 Spec. * @param theRange List objects of Double objects. * This is the Range of the function. * See page 264 of the PDF 1.3 Spec. * @param theFunctions A List of the PDFFunction objects that the stitching function stitches. * * This attributed is required. * It is described on page 269 of the PDF spec. * @param theBounds This is a vector of Doubles representing the numbers that, * in conjunction with Domain define the intervals to which each function from * the 'functions' object applies. It must be in order of increasing magnitude, * and each must be within Domain. * * It basically sets how much of the gradient each function handles. * * This attributed is required. * It's described on page 269 of the PDF 1.3 spec. * @param theEncode List objects of Double objects. * This is the linear mapping of input values intop the domain * of the function's sample table. Default is hard to represent in * ascii, but basically [0 (Size0 1) 0 (Size1 1)...]. * This attribute is required. * * See page 270 in the PDF 1.3 spec. * @param theFunctionType This is the function type. It should be 3, * for a stitching function. */ public PDFFunction(int theFunctionType, List theDomain, List theRange, List theFunctions, List theBounds, List theEncode) { super(); this.functionType = 3; // dang well better be 3; this.functions = theFunctions; this.bounds = theBounds; this.encode = theEncode; this.domain = theDomain; this.range = theRange; } /** * create an complete Function object of Type 4, a postscript calculator function. * * Use null for an optional object parameter if you choose not to use it. * For optional int parameters, pass the default. * * @param theDomain List object of Double objects. * This is the domain of the function. * See page 264 of the PDF 1.3 Spec. * @param theRange List object of Double objects. * This is the Range of the function. * See page 264 of the PDF 1.3 Spec. * @param theFunctionDataStream This is a stream of arithmetic, * boolean, and stack operators and boolean constants. * I end up enclosing it in the '{' and '}' braces for you, so don't do it * yourself. * * This attribute is required. * It's described on page 269 of the PDF 1.3 spec. * @param theFunctionType The type of function which should be 4, as this is * a Postscript calculator function */ public PDFFunction(int theFunctionType, List theDomain, List theRange, StringBuffer theFunctionDataStream) { super(); this.functionType = 4; // dang well better be 4; this.functionDataStream = theFunctionDataStream; this.domain = theDomain; this.range = theRange; } /** * 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() { int vectorSize = 0; int numberOfFunctions = 0; int tempInt = 0; StringBuffer p = new StringBuffer(256); p.append(getObjectID() + "<< \n/FunctionType " + this.functionType + " \n"); // FunctionType 0 if (this.functionType == 0) { if (this.domain != null) { // DOMAIN p.append("/Domain [ "); vectorSize = this.domain.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.domain.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Domain [ 0 1 ] \n"); } // SIZE if (this.size != null) { p.append("/Size [ "); vectorSize = this.size.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.size.get(tempInt)) + " "); } p.append("] \n"); } // ENCODE if (this.encode != null) { p.append("/Encode [ "); vectorSize = this.encode.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.encode.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Encode [ "); vectorSize = this.functions.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append("0 1 "); } p.append("] \n"); } // BITSPERSAMPLE p.append("/BitsPerSample " + this.bitsPerSample); // ORDER (optional) if (this.order == 1 || this.order == 3) { p.append(" \n/Order " + this.order + " \n"); } // RANGE if (this.range != null) { p.append("/Range [ "); vectorSize = this.range.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.range.get(tempInt)) + " "); } p.append("] \n"); } // DECODE if (this.decode != null) { p.append("/Decode [ "); vectorSize = this.decode.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.decode.get(tempInt)) + " "); } p.append("] \n"); } // LENGTH if (this.functionDataStream != null) { p.append("/Length " + (this.functionDataStream.length() + 1) + " \n"); } // FILTER? if (this.filter != null) { // if there's a filter vectorSize = this.filter.size(); p.append("/Filter "); if (vectorSize == 1) { p.append("/" + ((String)this.filter.get(0)) + " \n"); } else { p.append("[ "); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append("/" + ((String)this.filter.get(0)) + " "); } p.append("] \n"); } } p.append(">> \n"); // stream representing the function if (this.functionDataStream != null) { p.append("stream\n" + this.functionDataStream + "\nendstream\n"); } p.append("endobj\n"); // end of if FunctionType 0 } else if (this.functionType == 2) { // DOMAIN if (this.domain != null) { p.append("/Domain [ "); vectorSize = this.domain.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.domain.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Domain [ 0 1 ] \n"); } // RANGE if (this.range != null) { p.append("/Range [ "); vectorSize = this.range.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.range.get(tempInt)) + " "); } p.append("] \n"); } // FunctionType, C0, C1, N are required in PDF // C0 if (this.cZero != null) { p.append("/C0 [ "); vectorSize = this.cZero.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.cZero.get(tempInt)) + " "); } p.append("] \n"); } // C1 if (this.cOne != null) { p.append("/C1 [ "); vectorSize = this.cOne.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.cOne.get(tempInt)) + " "); } p.append("] \n"); } // N: The interpolation Exponent p.append("/N " + PDFNumber.doubleOut(new Double(this.interpolationExponentN)) + " \n"); p.append(">> \nendobj\n"); } else if (this.functionType == 3) { // fix this up when my eyes uncross // DOMAIN if (this.domain != null) { p.append("/Domain [ "); vectorSize = this.domain.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.domain.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Domain [ 0 1 ] \n"); } // RANGE if (this.range != null) { p.append("/Range [ "); vectorSize = this.range.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.range.get(tempInt)) + " "); } p.append("] \n"); } // FUNCTIONS if (this.functions != null) { p.append("/Functions [ "); numberOfFunctions = this.functions.size(); for (tempInt = 0; tempInt < numberOfFunctions; tempInt++) { p.append(((PDFFunction)this.functions.get(tempInt)).referencePDF() + " "); } p.append("] \n"); } // ENCODE if (this.encode != null) { p.append("/Encode [ "); vectorSize = this.encode.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.encode.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Encode [ "); vectorSize = this.functions.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append("0 1 "); } p.append("] \n"); } // BOUNDS, required, but can be empty p.append("/Bounds [ "); if (this.bounds != null) { vectorSize = this.bounds.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.bounds.get(tempInt)) + " "); } } else { if (this.functions != null) { // if there are n functions, // there must be n-1 bounds. // so let each function handle an equal portion // of the whole. e.g. if there are 4, then [ 0.25 0.25 0.25 ] String functionsFraction = PDFNumber.doubleOut(new Double(1.0 / ((double)numberOfFunctions))); for (tempInt = 0; tempInt + 1 < numberOfFunctions; tempInt++) { p.append(functionsFraction + " "); } functionsFraction = null; // clean reference. } } p.append("] \n"); p.append(">> \nendobj\n"); } else if (this.functionType == 4) { // fix this up when my eyes uncross // DOMAIN if (this.domain != null) { p.append("/Domain [ "); vectorSize = this.domain.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.domain.get(tempInt)) + " "); } p.append("] \n"); } else { p.append("/Domain [ 0 1 ] \n"); } // RANGE if (this.range != null) { p.append("/Range [ "); vectorSize = this.range.size(); for (tempInt = 0; tempInt < vectorSize; tempInt++) { p.append(PDFNumber.doubleOut((Double)this.range.get(tempInt)) + " "); } p.append("] \n"); } // LENGTH if (this.functionDataStream != null) { p.append("/Length " + (this.functionDataStream.length() + 1) + " \n"); } p.append(">> \n"); // stream representing the function if (this.functionDataStream != null) { p.append("stream\n{ " + this.functionDataStream + " } \nendstream\n"); } p.append("endobj\n"); } return encode(p.toString()); } /** * Check if this function is equal to another object. * This is used to find if a particular function already exists * in a document. * * @param obj the obj to compare * @return true if the functions are equal */ public boolean equals(Object obj) { if (obj == null) { return false; } if (obj == this) { return true; } if (!(obj instanceof PDFFunction)) { return false; } PDFFunction func = (PDFFunction)obj; if (functionType != func.functionType) { return false; } if (bitsPerSample != func.bitsPerSample) { return false; } if (order != func.order) { return false; } if (interpolationExponentN != func.interpolationExponentN) { return false; } if (domain != null) { if (!domain.equals(func.domain)) { return false; } } else if (func.domain != null) { return false; } if (range != null) { if (!range.equals(func.range)) { return false; } } else if (func.range != null) { return false; } if (size != null) { if (!size.equals(func.size)) { return false; } } else if (func.size != null) { return false; } if (encode != null) { if (!encode.equals(func.encode)) { return false; } } else if (func.encode != null) { return false; } if (decode != null) { if (!decode.equals(func.decode)) { return false; } } else if (func.decode != null) { return false; } if (functionDataStream != null) { if (!functionDataStream.equals(func.functionDataStream)) { return false; } } else if (func.functionDataStream != null) { return false; } if (filter != null) { if (!filter.equals(func.filter)) { return false; } } else if (func.filter != null) { return false; } if (cZero != null) { if (!cZero.equals(func.cZero)) { return false; } } else if (func.cZero != null) { return false; } if (cOne != null) { if (!cOne.equals(func.cOne)) { return false; } } else if (func.cOne != null) { return false; } if (functions != null) { if (!functions.equals(func.functions)) { return false; } } else if (func.functions != null) { return false; } if (bounds != null) { if (!bounds.equals(func.bounds)) { return false; } } else if (func.bounds != null) { return false; } return true; } }