fop/src/java/org/apache/fop/complexscripts/fonts/GlyphPositioningTable.java

/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.complexscripts.fonts;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.fop.complexscripts.scripts.ScriptProcessor;
import org.apache.fop.complexscripts.util.GlyphSequence;
import org.apache.fop.complexscripts.util.GlyphTester;

// CSOFF: LineLengthCheck
// CSOFF: InnerAssignmentCheck
// CSOFF: NoWhitespaceAfterCheck
// CSOFF: ParameterNumberCheck

/**
 * <p>The <code>GlyphPositioningTable</code> class is a glyph table that implements
 * <code>GlyphPositioning</code> functionality.</p>
 *
 * <p>This work was originally authored by Glenn Adams (gadams@apache.org).</p>
 */
public class GlyphPositioningTable extends GlyphTable {

    /** logging instance */
    private static final Log log = LogFactory.getLog(GlyphPositioningTable.class);                                      // CSOK: ConstantNameCheck

    /** single positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_SINGLE = 1;
    /** multiple positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_PAIR = 2;
    /** cursive positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_CURSIVE = 3;
    /** mark to base positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_MARK_TO_BASE = 4;
    /** mark to ligature positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_MARK_TO_LIGATURE = 5;
    /** mark to mark positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_MARK_TO_MARK = 6;
    /** contextual positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_CONTEXTUAL = 7;
    /** chained contextual positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_CHAINED_CONTEXTUAL = 8;
    /** extension positioning subtable type */
    public static final int GPOS_LOOKUP_TYPE_EXTENSION_POSITIONING = 9;

    /**
     * Instantiate a <code>GlyphPositioningTable</code> object using the specified lookups
     * and subtables.
     * @param gdef glyph definition table that applies
     * @param lookups a map of lookup specifications to subtable identifier strings
     * @param subtables a list of identified subtables
     */
    public GlyphPositioningTable ( GlyphDefinitionTable gdef, Map lookups, List subtables ) {
        super ( gdef, lookups );
        if ( ( subtables == null ) || ( subtables.size() == 0 ) ) {
            throw new AdvancedTypographicTableFormatException ( "subtables must be non-empty" );
        } else {
            for ( Iterator it = subtables.iterator(); it.hasNext();) {
                Object o = it.next();
                if ( o instanceof GlyphPositioningSubtable ) {
                    addSubtable ( (GlyphSubtable) o );
                } else {
                    throw new AdvancedTypographicTableFormatException ( "subtable must be a glyph positioning subtable" );
                }
            }
            freezeSubtables();
        }
    }

    /**
     * Map a lookup type name to its constant (integer) value.
     * @param name lookup type name
     * @return lookup type
     */
    public static int getLookupTypeFromName ( String name ) {
        int t;
        String s = name.toLowerCase();
        if ( "single".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_SINGLE;
        } else if ( "pair".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_PAIR;
        } else if ( "cursive".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_CURSIVE;
        } else if ( "marktobase".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_MARK_TO_BASE;
        } else if ( "marktoligature".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_MARK_TO_LIGATURE;
        } else if ( "marktomark".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_MARK_TO_MARK;
        } else if ( "contextual".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_CONTEXTUAL;
        } else if ( "chainedcontextual".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_CHAINED_CONTEXTUAL;
        } else if ( "extensionpositioning".equals ( s ) ) {
            t = GPOS_LOOKUP_TYPE_EXTENSION_POSITIONING;
        } else {
            t = -1;
        }
        return t;
    }

    /**
     * Map a lookup type constant (integer) value to its name.
     * @param type lookup type
     * @return lookup type name
     */
    public static String getLookupTypeName ( int type ) {
        String tn;
        switch ( type ) {
        case GPOS_LOOKUP_TYPE_SINGLE:
            tn = "single";
            break;
        case GPOS_LOOKUP_TYPE_PAIR:
            tn = "pair";
            break;
        case GPOS_LOOKUP_TYPE_CURSIVE:
            tn = "cursive";
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_BASE:
            tn = "marktobase";
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_LIGATURE:
            tn = "marktoligature";
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_MARK:
            tn = "marktomark";
            break;
        case GPOS_LOOKUP_TYPE_CONTEXTUAL:
            tn = "contextual";
            break;
        case GPOS_LOOKUP_TYPE_CHAINED_CONTEXTUAL:
            tn = "chainedcontextual";
            break;
        case GPOS_LOOKUP_TYPE_EXTENSION_POSITIONING:
            tn = "extensionpositioning";
            break;
        default:
            tn = "unknown";
            break;
        }
        return tn;
    }

    /**
     * Create a positioning subtable according to the specified arguments.
     * @param type subtable type
     * @param id subtable identifier
     * @param sequence subtable sequence
     * @param flags subtable flags
     * @param format subtable format
     * @param coverage subtable coverage table
     * @param entries subtable entries
     * @return a glyph subtable instance
     */
    public static GlyphSubtable createSubtable ( int type, String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
        GlyphSubtable st = null;
        switch ( type ) {
        case GPOS_LOOKUP_TYPE_SINGLE:
            st = SingleSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_PAIR:
            st = PairSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_CURSIVE:
            st = CursiveSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_BASE:
            st = MarkToBaseSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_LIGATURE:
            st = MarkToLigatureSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_MARK_TO_MARK:
            st = MarkToMarkSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_CONTEXTUAL:
            st = ContextualSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        case GPOS_LOOKUP_TYPE_CHAINED_CONTEXTUAL:
            st = ChainedContextualSubtable.create ( id, sequence, flags, format, coverage, entries );
            break;
        default:
            break;
        }
        return st;
    }

    /**
     * Create a positioning subtable according to the specified arguments.
     * @param type subtable type
     * @param id subtable identifier
     * @param sequence subtable sequence
     * @param flags subtable flags
     * @param format subtable format
     * @param coverage list of coverage table entries
     * @param entries subtable entries
     * @return a glyph subtable instance
     */
    public static GlyphSubtable createSubtable ( int type, String id, int sequence, int flags, int format, List coverage, List entries ) {
        return createSubtable ( type, id, sequence, flags, format, GlyphCoverageTable.createCoverageTable ( coverage ), entries );
    }

    /**
     * Perform positioning processing using all matching lookups.
     * @param gs an input glyph sequence
     * @param script a script identifier
     * @param language a language identifier
     * @param fontSize size in device units
     * @param widths array of default advancements for each glyph
     * @param adjustments accumulated adjustments array (sequence) of 4-tuples of placement [PX,PY] and advance [AX,AY] adjustments, in that order,
     * with one 4-tuple for each element of glyph sequence
     * @return true if some adjustment is not zero; otherwise, false
     */
    public boolean position ( GlyphSequence gs, String script, String language, int fontSize, int[] widths, int[][] adjustments ) {
        Map/*<LookupSpec,List<LookupTable>>*/ lookups = matchLookups ( script, language, "*" );
        if ( ( lookups != null ) && ( lookups.size() > 0 ) ) {
            ScriptProcessor sp = ScriptProcessor.getInstance ( script );
            return sp.position ( this, gs, script, language, fontSize, lookups, widths, adjustments );
        } else {
            return false;
        }
    }

    private abstract static class SingleSubtable extends GlyphPositioningSubtable {
        SingleSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_SINGLE;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof SingleSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            int gi = ps.getGlyph();
            int ci;
            if ( ( ci = getCoverageIndex ( gi ) ) < 0 ) {
                return false;
            } else {
                Value v = getValue ( ci, gi );
                if ( v != null ) {
                    if ( ps.adjust(v) ) {
                        ps.setAdjusted ( true );
                    }
                    ps.consume(1);
                }
                return true;
            }
        }
        /**
         * Obtain positioning value for coverage index.
         * @param ci coverage index
         * @param gi input glyph index
         * @return positioning value or null if none applies
         */
        public abstract Value getValue ( int ci, int gi );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new SingleSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 2 ) {
                return new SingleSubtableFormat2 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class SingleSubtableFormat1 extends SingleSubtable {
        private Value value;
        private int ciMax;
        SingleSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( value != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( value );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public Value getValue ( int ci, int gi ) {
            if ( ( value != null ) && ( ci <= ciMax ) ) {
                return value;
            } else {
                return null;
            }
        }
        private void populate ( List entries ) {
            if ( ( entries == null ) || ( entries.size() != 1 ) ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null and contain exactly one entry" );
            } else {
                Value v;
                Object o = entries.get(0);
                if ( o instanceof Value ) {
                    v = (Value) o;
                } else {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries entry, must be Value, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                }
                assert this.value == null;
                this.value = v;
                this.ciMax = getCoverageSize() - 1;
            }
        }
    }

    private static class SingleSubtableFormat2 extends SingleSubtable {
        private Value[] values;
        SingleSubtableFormat2 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( values != null ) {
                List entries = new ArrayList ( values.length );
                for ( int i = 0, n = values.length; i < n; i++ ) {
                    entries.add ( values[i] );
                }
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public Value getValue ( int ci, int gi ) {
            if ( ( values != null ) && ( ci < values.length ) ) {
                return values [ ci ];
            } else {
                return null;
            }
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof Value[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, single entry must be a Value[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    Value[] va = (Value[]) o;
                    if ( va.length != getCoverageSize() ) {
                        throw new AdvancedTypographicTableFormatException ( "illegal values array, " + entries.size() + " values present, but requires " + getCoverageSize() + " values" );
                    } else {
                        assert this.values == null;
                        this.values = va;
                    }
                }
            }
        }
    }

    private abstract static class PairSubtable extends GlyphPositioningSubtable {
        PairSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_PAIR;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof PairSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int gi = ps.getGlyph(0);
            int ci;
            if ( ( ci = getCoverageIndex ( gi ) ) >= 0 ) {
                int[] counts = ps.getGlyphsAvailable ( 0 );
                int nga = counts[0];
                if ( nga > 1 ) {
                    int[] iga = ps.getGlyphs ( 0, 2, null, counts );
                    if ( ( iga != null ) && ( iga.length == 2 ) ) {
                        PairValues pv = getPairValues ( ci, iga[0], iga[1] );
                        if ( pv != null ) {
                            Value v1 = pv.getValue1();
                            if ( v1 != null ) {
                                if ( ps.adjust(v1, 0) ) {
                                    ps.setAdjusted ( true );
                                }
                            }
                            Value v2 = pv.getValue2();
                            if ( v2 != null ) {
                                if ( ps.adjust(v2, 1) ) {
                                    ps.setAdjusted ( true );
                                }
                            }
                            ps.consume ( counts[0] + counts[1] );
                            applied = true;
                        }
                    }
                }
            }
            return applied;
        }
        /**
         * Obtain associated pair values.
         * @param ci coverage index
         * @param gi1 first input glyph index
         * @param gi2 second input glyph index
         * @return pair values or null if none applies
         */
        public abstract PairValues getPairValues ( int ci, int gi1, int gi2 );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new PairSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 2 ) {
                return new PairSubtableFormat2 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class PairSubtableFormat1 extends PairSubtable {
        private PairValues[][] pvm;                     // pair values matrix
        PairSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( pvm != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( pvm );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public PairValues getPairValues ( int ci, int gi1, int gi2 ) {
            if ( ( pvm != null ) && ( ci < pvm.length ) ) {
                PairValues[] pvt = pvm [ ci ];
                for ( int i = 0, n = pvt.length; i < n; i++ ) {
                    PairValues pv = pvt [ i ];
                    if ( pv != null ) {
                        int g = pv.getGlyph();
                        if ( g < gi2 ) {
                            continue;
                        } else if ( g == gi2 ) {
                            return pv;
                        } else {
                            break;
                        }
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof PairValues[][] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first (and only) entry must be a PairValues[][], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    pvm = (PairValues[][]) o;
                }
            }
        }
    }

    private static class PairSubtableFormat2 extends PairSubtable {
        private GlyphClassTable cdt1;                   // class def table 1
        private GlyphClassTable cdt2;                   // class def table 2
        private int nc1;                                // class 1 count
        private int nc2;                                // class 2 count
        private PairValues[][] pvm;                     // pair values matrix
        PairSubtableFormat2 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( pvm != null ) {
                List entries = new ArrayList ( 5 );
                entries.add ( cdt1 );
                entries.add ( cdt2 );
                entries.add ( Integer.valueOf ( nc1 ) );
                entries.add ( Integer.valueOf ( nc2 ) );
                entries.add ( pvm );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public PairValues getPairValues ( int ci, int gi1, int gi2 ) {
            if ( pvm != null ) {
                int c1 = cdt1.getClassIndex ( gi1, 0 );
                if ( ( c1 >= 0 ) && ( c1 < nc1 ) && ( c1 < pvm.length ) ) {
                    PairValues[] pvt = pvm [ c1 ];
                    if ( pvt != null ) {
                        int c2 = cdt2.getClassIndex ( gi2, 0 );
                        if ( ( c2 >= 0 ) && ( c2 < nc2 ) && ( c2 < pvt.length ) ) {
                            return pvt [ c2 ];
                        }
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 5 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 5 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphClassTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    cdt1 = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(1) ) == null ) || ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an GlyphClassTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    cdt2 = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(2) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    nc1 = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(3) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fourth entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    nc2 = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(4) ) == null ) || ! ( o instanceof PairValues[][] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fifth entry must be a PairValues[][], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    pvm = (PairValues[][]) o;
                }
            }
        }
    }

    private abstract static class CursiveSubtable extends GlyphPositioningSubtable {
        CursiveSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_CURSIVE;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof CursiveSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int gi = ps.getGlyph(0);
            int ci;
            if ( ( ci = getCoverageIndex ( gi ) ) >= 0 ) {
                int[] counts = ps.getGlyphsAvailable ( 0 );
                int nga = counts[0];
                if ( nga > 1 ) {
                    int[] iga = ps.getGlyphs ( 0, 2, null, counts );
                    if ( ( iga != null ) && ( iga.length == 2 ) ) {
                        // int gi1 = gi;
                        int ci1 = ci;
                        int gi2 = iga [ 1 ];
                        int ci2 = getCoverageIndex ( gi2 );
                        Anchor[] aa = getExitEntryAnchors ( ci1, ci2 );
                        if ( aa != null ) {
                            Anchor exa = aa [ 0 ];
                            Anchor ena = aa [ 1 ];
                            // int exw = ps.getWidth ( gi1 );
                            int enw = ps.getWidth ( gi2 );
                            if ( ( exa != null ) && ( ena != null ) ) {
                                Value v = ena.getAlignmentAdjustment ( exa );
                                v.adjust ( - enw, 0, 0, 0 );
                                if ( ps.adjust ( v ) ) {
                                    ps.setAdjusted ( true );
                                }
                            }
                            // consume only first glyph of exit/entry glyph pair
                            ps.consume ( 1 );
                            applied = true;
                        }
                    }
                }
            }
            return applied;
        }
        /**
         * Obtain exit anchor for first glyph with coverage index <code>ci1</code> and entry anchor for second
         * glyph with coverage index <code>ci2</code>.
         * @param ci1 coverage index of first glyph (may be negative)
         * @param ci2 coverage index of second glyph (may be negative)
         * @return array of two anchors or null if either coverage index is negative or corresponding anchor is
         * missing, where the first entry is the exit anchor of the first glyph and the second entry is the
         * entry anchor of the second glyph
         */
        public abstract Anchor[] getExitEntryAnchors ( int ci1, int ci2 );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new CursiveSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class CursiveSubtableFormat1 extends CursiveSubtable {
        private Anchor[] aa;                            // anchor array, where even entries are entry anchors, and odd entries are exit anchors
        CursiveSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( aa != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( aa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public Anchor[] getExitEntryAnchors ( int ci1, int ci2 ) {
            if ( ( ci1 >= 0 ) && ( ci2 >= 0 ) ) {
                int ai1 = ( ci1 * 2 ) + 1; // ci1 denotes glyph with exit anchor
                int ai2 = ( ci2 * 2 ) + 0; // ci2 denotes glyph with entry anchor
                if ( ( aa != null ) && ( ai1 < aa.length ) && ( ai2 < aa.length ) ) {
                    Anchor exa = aa [ ai1 ];
                    Anchor ena = aa [ ai2 ];
                    if ( ( exa != null ) && ( ena != null ) ) {
                        return new Anchor[] { exa, ena };
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof Anchor[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first (and only) entry must be a Anchor[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else if ( ( ( (Anchor[]) o ) . length % 2 ) != 0 ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, Anchor[] array must have an even number of entries, but has: " + ( (Anchor[]) o ) . length );
                } else {
                    aa = (Anchor[]) o;
                }
            }
        }
    }

    private abstract static class MarkToBaseSubtable extends GlyphPositioningSubtable {
        MarkToBaseSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_MARK_TO_BASE;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof MarkToBaseSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int giMark = ps.getGlyph();
            int ciMark;
            if ( ( ciMark = getCoverageIndex ( giMark ) ) >= 0 ) {
                MarkAnchor ma = getMarkAnchor ( ciMark, giMark );
                if ( ma != null ) {
                    for ( int i = 0, n = ps.getPosition(); i < n; i++ ) {
                        int gi = ps.getGlyph ( - ( i + 1 ) );
                        if ( ps.isMark ( gi ) ) {
                            continue;
                        } else {
                            Anchor a = getBaseAnchor ( gi, ma.getMarkClass() );
                            if ( a != null ) {
                                Value v = a.getAlignmentAdjustment ( ma );
                                // start experimental fix for END OF AYAH in Lateef/Scheherazade
                                int[] aa = ps.getAdjustment();
                                if ( aa[2] == 0 ) {
                                    v.adjust ( 0, 0, - ps.getWidth ( giMark ), 0 );
                                }
                                // end experimental fix for END OF AYAH in Lateef/Scheherazade
                                if ( ps.adjust ( v ) ) {
                                    ps.setAdjusted ( true );
                                }
                            }
                            ps.consume(1);
                            applied = true;
                            break;
                        }
                    }
                }
            }
            return applied;
        }
        /**
         * Obtain mark anchor associated with mark coverage index.
         * @param ciMark coverage index
         * @param giMark input glyph index of mark glyph
         * @return mark anchor or null if none applies
         */
        public abstract MarkAnchor getMarkAnchor ( int ciMark, int giMark );
        /**
         * Obtain anchor associated with base glyph index and mark class.
         * @param giBase input glyph index of base glyph
         * @param markClass class number of mark glyph
         * @return anchor or null if none applies
         */
        public abstract Anchor getBaseAnchor ( int giBase, int markClass );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new MarkToBaseSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class MarkToBaseSubtableFormat1 extends MarkToBaseSubtable {
        private GlyphCoverageTable bct;                 // base coverage table
        private int nmc;                                // mark class count
        private MarkAnchor[] maa;                       // mark anchor array, ordered by mark coverage index
        private Anchor[][] bam;                         // base anchor matrix, ordered by base coverage index, then by mark class
        MarkToBaseSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( ( bct != null ) && ( maa != null ) && ( nmc > 0 ) && ( bam != null ) ) {
                List entries = new ArrayList ( 4 );
                entries.add ( bct );
                entries.add ( Integer.valueOf ( nmc ) );
                entries.add ( maa );
                entries.add ( bam );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public MarkAnchor getMarkAnchor ( int ciMark, int giMark ) {
            if ( ( maa != null ) && ( ciMark < maa.length ) ) {
                return maa [ ciMark ];
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public Anchor getBaseAnchor ( int giBase, int markClass ) {
            int ciBase;
            if ( ( bct != null ) && ( ( ciBase = bct.getCoverageIndex ( giBase ) ) >= 0 ) ) {
                if ( ( bam != null ) && ( ciBase < bam.length ) ) {
                    Anchor[] ba = bam [ ciBase ];
                    if ( ( ba != null ) && ( markClass < ba.length ) ) {
                        return ba [ markClass ];
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 4 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 4 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphCoverageTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphCoverageTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    bct = (GlyphCoverageTable) o;
                }
                if ( ( ( o = entries.get(1) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    nmc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(2) ) == null ) || ! ( o instanceof MarkAnchor[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be a MarkAnchor[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    maa = (MarkAnchor[]) o;
                }
                if ( ( ( o = entries.get(3) ) == null ) || ! ( o instanceof Anchor[][] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fourth entry must be a Anchor[][], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    bam = (Anchor[][]) o;
                }
            }
        }
    }

    private abstract static class MarkToLigatureSubtable extends GlyphPositioningSubtable {
        MarkToLigatureSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_MARK_TO_LIGATURE;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof MarkToLigatureSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int giMark = ps.getGlyph();
            int ciMark;
            if ( ( ciMark = getCoverageIndex ( giMark ) ) >= 0 ) {
                MarkAnchor ma = getMarkAnchor ( ciMark, giMark );
                int mxc = getMaxComponentCount();
                if ( ma != null ) {
                    for ( int i = 0, n = ps.getPosition(); i < n; i++ ) {
                        int gi = ps.getGlyph ( - ( i + 1 ) );
                        if ( ps.isMark ( gi ) ) {
                            continue;
                        } else {
                            Anchor a = getLigatureAnchor ( gi, mxc, i, ma.getMarkClass() );
                            if ( a != null ) {
                                if ( ps.adjust ( a.getAlignmentAdjustment ( ma ) ) ) {
                                    ps.setAdjusted ( true );
                                }
                            }
                            ps.consume(1);
                            applied = true;
                            break;
                        }
                    }
                }
            }
            return applied;
        }
        /**
         * Obtain mark anchor associated with mark coverage index.
         * @param ciMark coverage index
         * @param giMark input glyph index of mark glyph
         * @return mark anchor or null if none applies
         */
        public abstract MarkAnchor getMarkAnchor ( int ciMark, int giMark );
        /**
         * Obtain maximum component count.
         * @return maximum component count (>=0)
         */
        public abstract int getMaxComponentCount();
        /**
         * Obtain anchor associated with ligature glyph index and mark class.
         * @param giLig input glyph index of ligature glyph
         * @param maxComponents maximum component count
         * @param component component number (0...maxComponents-1)
         * @param markClass class number of mark glyph
         * @return anchor or null if none applies
         */
        public abstract Anchor getLigatureAnchor ( int giLig, int maxComponents, int component, int markClass );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new MarkToLigatureSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class MarkToLigatureSubtableFormat1 extends MarkToLigatureSubtable {
        private GlyphCoverageTable lct;                 // ligature coverage table
        private int nmc;                                // mark class count
        private int mxc;                                // maximum ligature component count
        private MarkAnchor[] maa;                       // mark anchor array, ordered by mark coverage index
        private Anchor[][][] lam;                       // ligature anchor matrix, ordered by ligature coverage index, then ligature component, then mark class
        MarkToLigatureSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( lam != null ) {
                List entries = new ArrayList ( 5 );
                entries.add ( lct );
                entries.add ( Integer.valueOf ( nmc ) );
                entries.add ( Integer.valueOf ( mxc ) );
                entries.add ( maa );
                entries.add ( lam );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public MarkAnchor getMarkAnchor ( int ciMark, int giMark ) {
            if ( ( maa != null ) && ( ciMark < maa.length ) ) {
                return maa [ ciMark ];
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public int getMaxComponentCount() {
            return mxc;
        }
        /** {@inheritDoc} */
        public Anchor getLigatureAnchor ( int giLig, int maxComponents, int component, int markClass ) {
            int ciLig;
            if ( ( lct != null ) && ( ( ciLig = lct.getCoverageIndex ( giLig ) ) >= 0 ) ) {
                if ( ( lam != null ) && ( ciLig < lam.length ) ) {
                    Anchor[][] lcm = lam [ ciLig ];
                    if ( component < maxComponents ) {
                        Anchor[] la = lcm [ component ];
                        if ( ( la != null ) && ( markClass < la.length ) ) {
                            return la [ markClass ];
                        }
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 5 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 5 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphCoverageTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphCoverageTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    lct = (GlyphCoverageTable) o;
                }
                if ( ( ( o = entries.get(1) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    nmc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(2) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    mxc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(3) ) == null ) || ! ( o instanceof MarkAnchor[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fourth entry must be a MarkAnchor[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    maa = (MarkAnchor[]) o;
                }
                if ( ( ( o = entries.get(4) ) == null ) || ! ( o instanceof Anchor[][][] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fifth entry must be a Anchor[][][], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    lam = (Anchor[][][]) o;
                }
            }
        }
    }

    private abstract static class MarkToMarkSubtable extends GlyphPositioningSubtable {
        MarkToMarkSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_MARK_TO_MARK;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof MarkToMarkSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int giMark1 = ps.getGlyph();
            int ciMark1;
            if ( ( ciMark1 = getCoverageIndex ( giMark1 ) ) >= 0 ) {
                MarkAnchor ma = getMark1Anchor ( ciMark1, giMark1 );
                if ( ma != null ) {
                    if ( ps.hasPrev() ) {
                        Anchor a = getMark2Anchor ( ps.getGlyph(-1), ma.getMarkClass() );
                        if ( a != null ) {
                            if ( ps.adjust ( a.getAlignmentAdjustment ( ma ) ) ) {
                                ps.setAdjusted ( true );
                            }
                        }
                        ps.consume(1);
                        applied = true;
                    }
                }
            }
            return applied;
        }
        /**
         * Obtain mark 1 anchor associated with mark 1 coverage index.
         * @param ciMark1 mark 1 coverage index
         * @param giMark1 input glyph index of mark 1 glyph
         * @return mark 1 anchor or null if none applies
         */
        public abstract MarkAnchor getMark1Anchor ( int ciMark1, int giMark1 );
        /**
         * Obtain anchor associated with mark 2 glyph index and mark 1 class.
         * @param giMark2 input glyph index of mark 2 glyph
         * @param markClass class number of mark 1 glyph
         * @return anchor or null if none applies
         */
        public abstract Anchor getMark2Anchor ( int giBase, int markClass );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new MarkToMarkSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class MarkToMarkSubtableFormat1 extends MarkToMarkSubtable {
        private GlyphCoverageTable mct2;                // mark 2 coverage table
        private int nmc;                                // mark class count
        private MarkAnchor[] maa;                       // mark1 anchor array, ordered by mark1 coverage index
        private Anchor[][] mam;                         // mark2 anchor matrix, ordered by mark2 coverage index, then by mark1 class
        MarkToMarkSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( ( mct2 != null ) && ( maa != null ) && ( nmc > 0 ) && ( mam != null ) ) {
                List entries = new ArrayList ( 4 );
                entries.add ( mct2 );
                entries.add ( Integer.valueOf ( nmc ) );
                entries.add ( maa );
                entries.add ( mam );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public MarkAnchor getMark1Anchor ( int ciMark1, int giMark1 ) {
            if ( ( maa != null ) && ( ciMark1 < maa.length ) ) {
                return maa [ ciMark1 ];
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public Anchor getMark2Anchor ( int giMark2, int markClass ) {
            int ciMark2;
            if ( ( mct2 != null ) && ( ( ciMark2 = mct2.getCoverageIndex ( giMark2 ) ) >= 0 ) ) {
                if ( ( mam != null ) && ( ciMark2 < mam.length ) ) {
                    Anchor[] ma = mam [ ciMark2 ];
                    if ( ( ma != null ) && ( markClass < ma.length ) ) {
                        return ma [ markClass ];
                    }
                }
            }
            return null;
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 4 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 4 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphCoverageTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphCoverageTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    mct2 = (GlyphCoverageTable) o;
                }
                if ( ( ( o = entries.get(1) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    nmc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(2) ) == null ) || ! ( o instanceof MarkAnchor[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be a MarkAnchor[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    maa = (MarkAnchor[]) o;
                }
                if ( ( ( o = entries.get(3) ) == null ) || ! ( o instanceof Anchor[][] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fourth entry must be a Anchor[][], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    mam = (Anchor[][]) o;
                }
            }
        }
    }

    private abstract static class ContextualSubtable extends GlyphPositioningSubtable {
        ContextualSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_CONTEXTUAL;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof ContextualSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int gi = ps.getGlyph();
            int ci;
            if ( ( ci = getCoverageIndex ( gi ) ) >= 0 ) {
                int[] rv = new int[1];
                RuleLookup[] la = getLookups ( ci, gi, ps, rv );
                if ( la != null ) {
                    ps.apply ( la, rv[0] );
                    applied = true;
                }
            }
            return applied;
        }
        /**
         * Obtain rule lookups set associated current input glyph context.
         * @param ci coverage index of glyph at current position
         * @param gi glyph index of glyph at current position
         * @param ps glyph positioning state
         * @param rv array of ints used to receive multiple return values, must be of length 1 or greater,
         * where the first entry is used to return the input sequence length of the matched rule
         * @return array of rule lookups or null if none applies
         */
        public abstract RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new ContextualSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 2 ) {
                return new ContextualSubtableFormat2 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 3 ) {
                return new ContextualSubtableFormat3 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class ContextualSubtableFormat1 extends ContextualSubtable {
        private RuleSet[] rsa;                          // rule set array, ordered by glyph coverage index
        ContextualSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedGlyphSequenceRule ) ) {
                            ChainedGlyphSequenceRule cr = (ChainedGlyphSequenceRule) r;
                            int[] iga = cr.getGlyphs ( gi );
                            if ( matches ( ps, iga, 0, rv ) ) {
                                return r.getLookups();
                            }
                        }
                    }
                }
            }
            return null;
        }
        static boolean matches ( GlyphPositioningState ps, int[] glyphs, int offset, int[] rv ) {
            if ( ( glyphs == null ) || ( glyphs.length == 0 ) ) {
                return true;                            // match null or empty glyph sequence
            } else {
                boolean reverse = offset < 0;
                GlyphTester ignores = ps.getIgnoreDefault();
                int[] counts = ps.getGlyphsAvailable ( offset, reverse, ignores );
                int nga = counts[0];
                int ngm = glyphs.length;
                if ( nga < ngm ) {
                    return false;                       // insufficient glyphs available to match
                } else {
                    int[] ga = ps.getGlyphs ( offset, ngm, reverse, ignores, null, counts );
                    for ( int k = 0; k < ngm; k++ ) {
                        if ( ga [ k ] != glyphs [ k ] ) {
                            return false;               // match fails at ga [ k ]
                        }
                    }
                    if ( rv != null ) {
                        rv[0] = counts[0] + counts[1];
                    }
                    return true;                        // all glyphs match
                }
            }
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                }
            }
        }
    }

    private static class ContextualSubtableFormat2 extends ContextualSubtable {
        private GlyphClassTable cdt;                    // class def table
        private int ngc;                                // class set count
        private RuleSet[] rsa;                          // rule set array, ordered by class number [0...ngc - 1]
        ContextualSubtableFormat2 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 3 );
                entries.add ( cdt );
                entries.add ( Integer.valueOf ( ngc ) );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedClassSequenceRule ) ) {
                            ChainedClassSequenceRule cr = (ChainedClassSequenceRule) r;
                            int[] ca = cr.getClasses ( cdt.getClassIndex ( gi, ps.getClassMatchSet ( gi ) ) );
                            if ( matches ( ps, cdt, ca, 0, rv ) ) {
                                return r.getLookups();
                            }
                        }
                    }
                }
            }
            return null;
        }
        static boolean matches ( GlyphPositioningState ps, GlyphClassTable cdt, int[] classes, int offset, int[] rv ) {
            if ( ( cdt == null ) || ( classes == null ) || ( classes.length == 0 ) ) {
                return true;                            // match null class definitions, null or empty class sequence
            } else {
                boolean reverse = offset < 0;
                GlyphTester ignores = ps.getIgnoreDefault();
                int[] counts = ps.getGlyphsAvailable ( offset, reverse, ignores );
                int nga = counts[0];
                int ngm = classes.length;
                if ( nga < ngm ) {
                    return false;                       // insufficient glyphs available to match
                } else {
                    int[] ga = ps.getGlyphs ( offset, ngm, reverse, ignores, null, counts );
                    for ( int k = 0; k < ngm; k++ ) {
                        int gi = ga [ k ];
                        int ms = ps.getClassMatchSet ( gi );
                        int gc = cdt.getClassIndex ( gi, ms );
                        if ( ( gc < 0 ) || ( gc >= cdt.getClassSize ( ms ) ) ) {
                            return false;               // none or invalid class fails mat ch
                        } else if ( gc != classes [ k ] ) {
                            return false;               // match fails at ga [ k ]
                        }
                    }
                    if ( rv != null ) {
                        rv[0] = counts[0] + counts[1];
                    }
                    return true;                        // all glyphs match
                }
            }
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 3 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 3 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphClassTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    cdt = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(1) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    ngc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(2) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                    if ( rsa.length != ngc ) {
                        throw new AdvancedTypographicTableFormatException ( "illegal entries, RuleSet[] length is " + rsa.length + ", but expected " + ngc + " glyph classes" );
                    }
                }
            }
        }
    }

    private static class ContextualSubtableFormat3 extends ContextualSubtable {
        private RuleSet[] rsa;                          // rule set array, containing a single rule set
        ContextualSubtableFormat3 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedCoverageSequenceRule ) ) {
                            ChainedCoverageSequenceRule cr = (ChainedCoverageSequenceRule) r;
                            GlyphCoverageTable[] gca = cr.getCoverages();
                            if ( matches ( ps, gca, 0, rv ) ) {
                                return r.getLookups();
                            }
                        }
                    }
                }
            }
            return null;
        }
        static boolean matches ( GlyphPositioningState ps, GlyphCoverageTable[] gca, int offset, int[] rv ) {
            if ( ( gca == null ) || ( gca.length == 0 ) ) {
                return true;                            // match null or empty coverage array
            } else {
                boolean reverse = offset < 0;
                GlyphTester ignores = ps.getIgnoreDefault();
                int[] counts = ps.getGlyphsAvailable ( offset, reverse, ignores );
                int nga = counts[0];
                int ngm = gca.length;
                if ( nga < ngm ) {
                    return false;                       // insufficient glyphs available to match
                } else {
                    int[] ga = ps.getGlyphs ( offset, ngm, reverse, ignores, null, counts );
                    for ( int k = 0; k < ngm; k++ ) {
                        GlyphCoverageTable ct = gca [ k ];
                        if ( ct != null ) {
                            if ( ct.getCoverageIndex ( ga [ k ] ) < 0 ) {
                                return false;           // match fails at ga [ k ]
                            }
                        }
                    }
                    if ( rv != null ) {
                        rv[0] = counts[0] + counts[1];
                    }
                    return true;                        // all glyphs match
                }
            }
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                }
            }
        }
    }

    private abstract static class ChainedContextualSubtable extends GlyphPositioningSubtable {
        ChainedContextualSubtable ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage );
        }
        /** {@inheritDoc} */
        public int getType() {
            return GPOS_LOOKUP_TYPE_CHAINED_CONTEXTUAL;
        }
        /** {@inheritDoc} */
        public boolean isCompatible ( GlyphSubtable subtable ) {
            return subtable instanceof ChainedContextualSubtable;
        }
        /** {@inheritDoc} */
        public boolean position ( GlyphPositioningState ps ) {
            boolean applied = false;
            int gi = ps.getGlyph();
            int ci;
            if ( ( ci = getCoverageIndex ( gi ) ) >= 0 ) {
                int[] rv = new int[1];
                RuleLookup[] la = getLookups ( ci, gi, ps, rv );
                if ( la != null ) {
                    ps.apply ( la, rv[0] );
                    applied = true;
                }
            }
            return applied;
        }
        /**
         * Obtain rule lookups set associated current input glyph context.
         * @param ci coverage index of glyph at current position
         * @param gi glyph index of glyph at current position
         * @param ps glyph positioning state
         * @param rv array of ints used to receive multiple return values, must be of length 1 or greater,
         * where the first entry is used to return the input sequence length of the matched rule
         * @return array of rule lookups or null if none applies
         */
        public abstract RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv );
        static GlyphPositioningSubtable create ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            if ( format == 1 ) {
                return new ChainedContextualSubtableFormat1 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 2 ) {
                return new ChainedContextualSubtableFormat2 ( id, sequence, flags, format, coverage, entries );
            } else if ( format == 3 ) {
                return new ChainedContextualSubtableFormat3 ( id, sequence, flags, format, coverage, entries );
            } else {
                throw new UnsupportedOperationException();
            }
        }
    }

    private static class ChainedContextualSubtableFormat1 extends ChainedContextualSubtable {
        private RuleSet[] rsa;                          // rule set array, ordered by glyph coverage index
        ChainedContextualSubtableFormat1 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedGlyphSequenceRule ) ) {
                            ChainedGlyphSequenceRule cr = (ChainedGlyphSequenceRule) r;
                            int[] iga = cr.getGlyphs ( gi );
                            if ( matches ( ps, iga, 0, rv ) ) {
                                int[] bga = cr.getBacktrackGlyphs();
                                if ( matches ( ps, bga, -1, null ) ) {
                                    int[] lga = cr.getLookaheadGlyphs();
                                    if ( matches ( ps, lga, rv[0], null ) ) {
                                        return r.getLookups();
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return null;
        }
        private boolean matches ( GlyphPositioningState ps, int[] glyphs, int offset, int[] rv ) {
            return ContextualSubtableFormat1.matches ( ps, glyphs, offset, rv );
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                }
            }
        }
    }

    private static class ChainedContextualSubtableFormat2 extends ChainedContextualSubtable {
        private GlyphClassTable icdt;                   // input class def table
        private GlyphClassTable bcdt;                   // backtrack class def table
        private GlyphClassTable lcdt;                   // lookahead class def table
        private int ngc;                                // class set count
        private RuleSet[] rsa;                          // rule set array, ordered by class number [0...ngc - 1]
        ChainedContextualSubtableFormat2 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 5 );
                entries.add ( icdt );
                entries.add ( bcdt );
                entries.add ( lcdt );
                entries.add ( Integer.valueOf ( ngc ) );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedClassSequenceRule ) ) {
                            ChainedClassSequenceRule cr = (ChainedClassSequenceRule) r;
                            int[] ica = cr.getClasses ( icdt.getClassIndex ( gi, ps.getClassMatchSet ( gi ) ) );
                            if ( matches ( ps, icdt, ica, 0, rv ) ) {
                                int[] bca = cr.getBacktrackClasses();
                                if ( matches ( ps, bcdt, bca, -1, null ) ) {
                                    int[] lca = cr.getLookaheadClasses();
                                    if ( matches ( ps, lcdt, lca, rv[0], null ) ) {
                                        return r.getLookups();
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return null;
        }
        private boolean matches ( GlyphPositioningState ps, GlyphClassTable cdt, int[] classes, int offset, int[] rv ) {
            return ContextualSubtableFormat2.matches ( ps, cdt, classes, offset, rv );
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 5 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 5 entries" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an GlyphClassTable, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    icdt = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(1) ) != null ) && ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, second entry must be an GlyphClassTable, but is: " + o.getClass() );
                } else {
                    bcdt = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(2) ) != null ) && ! ( o instanceof GlyphClassTable ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, third entry must be an GlyphClassTable, but is: " + o.getClass() );
                } else {
                    lcdt = (GlyphClassTable) o;
                }
                if ( ( ( o = entries.get(3) ) == null ) || ! ( o instanceof Integer ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fourth entry must be an Integer, but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    ngc = ((Integer)(o)).intValue();
                }
                if ( ( ( o = entries.get(4) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, fifth entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                    if ( rsa.length != ngc ) {
                        throw new AdvancedTypographicTableFormatException ( "illegal entries, RuleSet[] length is " + rsa.length + ", but expected " + ngc + " glyph classes" );
                    }
                }
            }
        }
    }

    private static class ChainedContextualSubtableFormat3 extends ChainedContextualSubtable {
        private RuleSet[] rsa;                          // rule set array, containing a single rule set
        ChainedContextualSubtableFormat3 ( String id, int sequence, int flags, int format, GlyphCoverageTable coverage, List entries ) {
            super ( id, sequence, flags, format, coverage, entries );
            populate ( entries );
        }
        /** {@inheritDoc} */
        public List getEntries() {
            if ( rsa != null ) {
                List entries = new ArrayList ( 1 );
                entries.add ( rsa );
                return entries;
            } else {
                return null;
            }
        }
        /** {@inheritDoc} */
        public void resolveLookupReferences ( Map/*<String,LookupTable>*/ lookupTables ) {
            GlyphTable.resolveLookupReferences ( rsa, lookupTables );
        }
        /** {@inheritDoc} */
        public RuleLookup[] getLookups ( int ci, int gi, GlyphPositioningState ps, int[] rv  ) {
            assert ps != null;
            assert ( rv != null ) && ( rv.length > 0 );
            assert rsa != null;
            if ( rsa.length > 0 ) {
                RuleSet rs = rsa [ 0 ];
                if ( rs != null ) {
                    Rule[] ra = rs.getRules();
                    for ( int i = 0, n = ra.length; i < n; i++ ) {
                        Rule r = ra [ i ];
                        if ( ( r != null ) && ( r instanceof ChainedCoverageSequenceRule ) ) {
                            ChainedCoverageSequenceRule cr = (ChainedCoverageSequenceRule) r;
                            GlyphCoverageTable[] igca = cr.getCoverages();
                            if ( matches ( ps, igca, 0, rv ) ) {
                                GlyphCoverageTable[] bgca = cr.getBacktrackCoverages();
                                if ( matches ( ps, bgca, -1, null ) ) {
                                    GlyphCoverageTable[] lgca = cr.getLookaheadCoverages();
                                    if ( matches ( ps, lgca, rv[0], null ) ) {
                                        return r.getLookups();
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return null;
        }
        private boolean matches ( GlyphPositioningState ps, GlyphCoverageTable[] gca, int offset, int[] rv ) {
            return ContextualSubtableFormat3.matches ( ps, gca, offset, rv );
        }
        private void populate ( List entries ) {
            if ( entries == null ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, must be non-null" );
            } else if ( entries.size() != 1 ) {
                throw new AdvancedTypographicTableFormatException ( "illegal entries, " + entries.size() + " entries present, but requires 1 entry" );
            } else {
                Object o;
                if ( ( ( o = entries.get(0) ) == null ) || ! ( o instanceof RuleSet[] ) ) {
                    throw new AdvancedTypographicTableFormatException ( "illegal entries, first entry must be an RuleSet[], but is: " + ( ( o != null ) ? o.getClass() : null ) );
                } else {
                    rsa = (RuleSet[]) o;
                }
            }
        }
    }

    /**
     * The <code>DeviceTable</code> class implements a positioning device table record, comprising
     * adjustments to be made to scaled design units according to the scaled size.
     */
    public static class DeviceTable {

        private final int startSize;
        private final int endSize;
        private final int[] deltas;

        /**
         * Instantiate a DeviceTable.
         * @param startSize the
         * @param endSize the ending (scaled) size
         * @param deltas adjustments for each scaled size
         */
        public DeviceTable ( int startSize, int endSize, int[] deltas ) {
            assert startSize >= 0;
            assert startSize <= endSize;
            assert deltas != null;
            assert deltas.length == ( endSize - startSize ) + 1;
            this.startSize = startSize;
            this.endSize = endSize;
            this.deltas = deltas;
        }

        /** @return the start size */
        public int getStartSize() {
            return startSize;
        }

        /** @return the end size */
        public int getEndSize() {
            return endSize;
        }

        /** @return the deltas */
        public int[] getDeltas() {
            return deltas;
        }

        /**
         * Find device adjustment.
         * @param fontSize the font size to search for
         * @return an adjustment if font size matches an entry
         */
        public int findAdjustment ( int fontSize ) {
            // [TODO] at present, assumes that 1 device unit equals one point
            int fs = fontSize / 1000;
            if ( fs < startSize ) {
                return 0;
            } else if ( fs <= endSize ) {
                return deltas [ fs - startSize ] * 1000;
            } else {
                return 0;
            }
        }

        /** {@inheritDoc} */
        public String toString() {
            return "{ start = " + startSize + ", end = " + endSize + ", deltas = " + Arrays.toString ( deltas ) + "}";
        }

    }

    /**
     * The <code>Value</code> class implements a positioning value record, comprising placement
     * and advancement information in X and Y axes, and optionally including device data used to
     * perform device (grid-fitted) specific fine grain adjustments.
     */
    public static class Value {

        /** X_PLACEMENT value format flag */
        public static final int X_PLACEMENT             = 0x0001;
        /** Y_PLACEMENT value format flag */
        public static final int Y_PLACEMENT             = 0x0002;
        /** X_ADVANCE value format flag */
        public static final int X_ADVANCE               = 0x0004;
        /** Y_ADVANCE value format flag */
        public static final int Y_ADVANCE               = 0x0008;
        /** X_PLACEMENT_DEVICE value format flag */
        public static final int X_PLACEMENT_DEVICE      = 0x0010;
        /** Y_PLACEMENT_DEVICE value format flag */
        public static final int Y_PLACEMENT_DEVICE      = 0x0020;
        /** X_ADVANCE_DEVICE value format flag */
        public static final int X_ADVANCE_DEVICE        = 0x0040;
        /** Y_ADVANCE_DEVICE value format flag */
        public static final int Y_ADVANCE_DEVICE        = 0x0080;

        /** X_PLACEMENT value index (within adjustments arrays) */
        public static final int IDX_X_PLACEMENT         = 0;
        /** Y_PLACEMENT value index (within adjustments arrays) */
        public static final int IDX_Y_PLACEMENT         = 1;
        /** X_ADVANCE value index (within adjustments arrays) */
        public static final int IDX_X_ADVANCE           = 2;
        /** Y_ADVANCE value index (within adjustments arrays) */
        public static final int IDX_Y_ADVANCE           = 3;

        private int xPlacement;                         // x placement
        private int yPlacement;                         // y placement
        private int xAdvance;                           // x advance
        private int yAdvance;                           // y advance
        private final DeviceTable xPlaDevice;           // x placement device table
        private final DeviceTable yPlaDevice;           // y placement device table
        private final DeviceTable xAdvDevice;           // x advance device table
        private final DeviceTable yAdvDevice;           // x advance device table

        /**
         * Instantiate a Value.
         * @param xPlacement the x placement or zero
         * @param yPlacement the y placement or zero
         * @param xAdvance the x advance or zero
         * @param yAdvance the y advance or zero
         * @param xPlaDevice the x placement device table or null
         * @param yPlaDevice the y placement device table or null
         * @param xAdvDevice the x advance device table or null
         * @param yAdvDevice the y advance device table or null
         */
        public Value ( int xPlacement, int yPlacement, int xAdvance, int yAdvance, DeviceTable xPlaDevice, DeviceTable yPlaDevice, DeviceTable xAdvDevice, DeviceTable yAdvDevice ) {
            this.xPlacement = xPlacement;
            this.yPlacement = yPlacement;
            this.xAdvance = xAdvance;
            this.yAdvance = yAdvance;
            this.xPlaDevice = xPlaDevice;
            this.yPlaDevice = yPlaDevice;
            this.xAdvDevice = xAdvDevice;
            this.yAdvDevice = yAdvDevice;
        }

        /** @return the x placement */
        public int getXPlacement() {
            return xPlacement;
        }

        /** @return the y placement */
        public int getYPlacement() {
            return yPlacement;
        }

        /** @return the x advance */
        public int getXAdvance() {
            return xAdvance;
        }

        /** @return the y advance */
        public int getYAdvance() {
            return yAdvance;
        }

        /** @return the x placement device table */
        public DeviceTable getXPlaDevice() {
            return xPlaDevice;
        }

        /** @return the y placement device table */
        public DeviceTable getYPlaDevice() {
            return yPlaDevice;
        }

        /** @return the x advance device table */
        public DeviceTable getXAdvDevice() {
            return xAdvDevice;
        }

        /** @return the y advance device table */
        public DeviceTable getYAdvDevice() {
            return yAdvDevice;
        }

        /**
         * Apply value to specific adjustments to without use of device table adjustments.
         * @param xPlacement the x placement or zero
         * @param yPlacement the y placement or zero
         * @param xAdvance the x advance or zero
         * @param yAdvance the y advance or zero
         */
        public void adjust ( int xPlacement, int yPlacement, int xAdvance, int yAdvance ) {
            this.xPlacement += xPlacement;
            this.yPlacement += yPlacement;
            this.xAdvance += xAdvance;
            this.yAdvance += yAdvance;
        }

        /**
         * Apply value to adjustments using font size for device table adjustments.
         * @param adjustments array of four integers containing X,Y placement and X,Y advance adjustments
         * @param fontSize font size for device table adjustments
         * @return true if some adjustment was made
         */
        public boolean adjust ( int[] adjustments, int fontSize ) {
            boolean adjust = false;
            int dv;
            if ( ( dv = xPlacement ) != 0 ) {
                adjustments [ IDX_X_PLACEMENT ] += dv;
                adjust = true;
            }
            if ( ( dv = yPlacement ) != 0 ) {
                adjustments [ IDX_Y_PLACEMENT ] += dv;
                adjust = true;
            }
            if ( ( dv = xAdvance ) != 0 ) {
                adjustments [ IDX_X_ADVANCE ] += dv;
                adjust = true;
            }
            if ( ( dv = yAdvance ) != 0 ) {
                adjustments [ IDX_Y_ADVANCE ] += dv;
                adjust = true;
            }
            if ( fontSize != 0 ) {
                DeviceTable dt;
                if ( ( dt = xPlaDevice ) != null ) {
                    if ( ( dv = dt.findAdjustment ( fontSize ) ) != 0 ) {
                        adjustments [ IDX_X_PLACEMENT ] += dv;
                        adjust = true;
                    }
                }
                if ( ( dt = yPlaDevice ) != null ) {
                    if ( ( dv = dt.findAdjustment ( fontSize ) ) != 0 ) {
                        adjustments [ IDX_Y_PLACEMENT ] += dv;
                        adjust = true;
                    }
                }
                if ( ( dt = xAdvDevice ) != null ) {
                    if ( ( dv = dt.findAdjustment ( fontSize ) ) != 0 ) {
                        adjustments [ IDX_X_ADVANCE ] += dv;
                        adjust = true;
                    }
                }
                if ( ( dt = yAdvDevice ) != null ) {
                    if ( ( dv = dt.findAdjustment ( fontSize ) ) != 0 ) {
                        adjustments [ IDX_Y_ADVANCE ] += dv;
                        adjust = true;
                    }
                }
            }
            return adjust;
        }

        /** {@inheritDoc} */
        public String toString() {
            StringBuffer sb = new StringBuffer();
            boolean first = true;
            sb.append ( "{ " );
            if ( xPlacement != 0 ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xPlacement = " + xPlacement );
            }
            if ( yPlacement != 0 ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "yPlacement = " + yPlacement );
            }
            if ( xAdvance != 0 ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xAdvance = " + xAdvance );
            }
            if ( yAdvance != 0 ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "yAdvance = " + yAdvance );
            }
            if ( xPlaDevice != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xPlaDevice = " + xPlaDevice );
            }
            if ( yPlaDevice != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xPlaDevice = " + yPlaDevice );
            }
            if ( xAdvDevice != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xAdvDevice = " + xAdvDevice );
            }
            if ( yAdvDevice != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "xAdvDevice = " + yAdvDevice );
            }
            sb.append(" }");
            return sb.toString();
        }

    }

    /**
     * The <code>PairValues</code> class implements a pair value record, comprising a glyph id (or zero)
     * and two optional positioning values.
     */
    public static class PairValues {

        private final int glyph;                        // glyph id (or 0)
        private final Value value1;                     // value for first glyph in pair (or null)
        private final Value value2;                     // value for second glyph in pair (or null)

        /**
         * Instantiate a PairValues.
         * @param glyph the glyph id (or zero)
         * @param value1 the value of the first glyph in pair (or null)
         * @param value2 the value of the second glyph in pair (or null)
         */
        public PairValues ( int glyph, Value value1, Value value2 ) {
            assert glyph >= 0;
            this.glyph = glyph;
            this.value1 = value1;
            this.value2 = value2;
        }

        /** @return the glyph id */
        public int getGlyph() {
            return glyph;
        }

        /** @return the first value */
        public Value getValue1() {
            return value1;
        }

        /** @return the second value */
        public Value getValue2() {
            return value2;
        }

        /** {@inheritDoc} */
        public String toString() {
            StringBuffer sb = new StringBuffer();
            boolean first = true;
            sb.append ( "{ " );
            if ( glyph != 0 ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "glyph = " + glyph );
            }
            if ( value1 != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "value1 = " + value1 );
            }
            if ( value2 != null ) {
                if ( ! first ) {
                    sb.append ( ", " );
                } else {
                    first = false;
                }
                sb.append ( "value2 = " + value2 );
            }
            sb.append(" }");
            return sb.toString();
        }

    }

    /**
     * The <code>Anchor</code> class implements a anchor record, comprising an X,Y coordinate pair,
     * an optional anchor point index (or -1), and optional X or Y device tables (or null if absent).
     */
    public static class Anchor {

        private final int x;                            // xCoordinate (in design units)
        private final int y;                            // yCoordinate (in design units)
        private final int anchorPoint;                  // anchor point index (or -1)
        private final DeviceTable xDevice;              // x device table
        private final DeviceTable yDevice;              // y device table

        /**
         * Instantiate an Anchor (format 1).
         * @param x the x coordinate
         * @param y the y coordinate
         */
        public Anchor ( int x, int y ) {
            this ( x, y, -1, null, null );
        }

        /**
         * Instantiate an Anchor (format 2).
         * @param x the x coordinate
         * @param y the y coordinate
         * @param anchorPoint anchor index (or -1)
         */
        public Anchor ( int x, int y, int anchorPoint ) {
            this ( x, y, anchorPoint, null, null );
        }

        /**
         * Instantiate an Anchor (format 3).
         * @param x the x coordinate
         * @param y the y coordinate
         * @param xDevice the x device table (or null if not present)
         * @param yDevice the y device table (or null if not present)
         */
        public Anchor ( int x, int y, DeviceTable xDevice, DeviceTable yDevice ) {
            this ( x, y, -1, xDevice, yDevice );
        }

        /**
         * Instantiate an Anchor based on an existing anchor.
         * @param a the existing anchor
         */
        protected Anchor ( Anchor a ) {
            this ( a.x, a.y, a.anchorPoint, a.xDevice, a.yDevice );
        }

        private Anchor ( int x, int  y, int anchorPoint, DeviceTable xDevice, DeviceTable yDevice ) {
            assert ( anchorPoint >= 0 ) || ( anchorPoint == -1 );
            this.x = x;
            this.y = y;
            this.anchorPoint = anchorPoint;
            this.xDevice = xDevice;
            this.yDevice = yDevice;
        }

        /** @return the x coordinate */
        public int getX() {
            return x;
        }

        /** @return the y coordinate */
        public int getY() {
            return y;
        }

        /** @return the anchor point index (or -1 if not specified) */
        public int getAnchorPoint() {
            return anchorPoint;
        }

        /** @return the x device table (or null if not specified) */
        public DeviceTable getXDevice() {
            return xDevice;
        }

        /** @return the y device table (or null if not specified) */
        public DeviceTable getYDevice() {
            return yDevice;
        }

        /**
         * Obtain adjustment value required to align the specified anchor
         * with this anchor.
         * @param a the anchor to align
         * @return the adjustment value needed to effect alignment
         */
        public Value getAlignmentAdjustment ( Anchor a ) {
            assert a != null;
            // TODO - handle anchor point
            // TODO - handle device tables
            return new Value ( x - a.x, y - a.y, 0, 0, null, null, null, null );
        }

        /** {@inheritDoc} */
        public String toString() {
            StringBuffer sb = new StringBuffer();
            sb.append ( "{ [" + x + "," + y + "]" );
            if ( anchorPoint != -1 ) {
                sb.append ( ", anchorPoint = " + anchorPoint );
            }
            if ( xDevice != null ) {
                sb.append ( ", xDevice = " + xDevice );
            }
            if ( yDevice != null ) {
                sb.append ( ", yDevice = " + yDevice );
            }
            sb.append(" }");
            return sb.toString();
        }

    }

    /**
     * The <code>MarkAnchor</code> class is a subclass of the <code>Anchor</code> class, adding a mark
     * class designation.
     */
    public static class MarkAnchor extends Anchor {

        private final int markClass;                            // mark class

        /**
         * Instantiate a MarkAnchor
         * @param markClass the mark class
         * @param a the underlying anchor (whose fields are copied)
         */
        public MarkAnchor ( int markClass, Anchor a ) {
            super ( a );
            this.markClass = markClass;
        }

        /** @return the mark class */
        public int getMarkClass() {
            return markClass;
        }

        /** {@inheritDoc} */
        public String toString() {
            return "{ markClass = " + markClass + ", anchor = " + super.toString() + " }";
        }

    }

}