/*
 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
/*
 *
 * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
 */

package sun.font;

import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Shape;

import java.awt.font.FontRenderContext;
import java.awt.font.GlyphJustificationInfo;
import java.awt.font.GlyphMetrics;
import java.awt.font.LineMetrics;
import java.awt.font.TextAttribute;

import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

import java.util.Map;

Default implementation of ExtendedTextLabel.
/**
 * Default implementation of ExtendedTextLabel.
 */

// {jbr} I made this class package-private to keep the
// Decoration.Label API package-private.

/* public */
class ExtendedTextSourceLabel extends ExtendedTextLabel implements Decoration.Label {

  TextSource source;
  private Decoration decorator;

  // caches
  private Font font;
  private AffineTransform baseTX;
  private CoreMetrics cm;

  Rectangle2D lb;
  Rectangle2D ab;
  Rectangle2D vb;
  Rectangle2D ib;
  StandardGlyphVector gv;
  float[] charinfo;

  
Create from a TextSource.
/**
   * Create from a TextSource.
   */
  public ExtendedTextSourceLabel(TextSource source, Decoration decorator) {
    this.source = source;
    this.decorator = decorator;
    finishInit();
  }

  
Create from a TextSource, optionally using cached data from oldLabel starting at the offset.
If present oldLabel must have been created from a run of text that includes the text used in
the new label.  Start in source corresponds to logical character offset in oldLabel.
/**
   * Create from a TextSource, optionally using cached data from oldLabel starting at the offset.
   * If present oldLabel must have been created from a run of text that includes the text used in
   * the new label.  Start in source corresponds to logical character offset in oldLabel.
   */
  public ExtendedTextSourceLabel(TextSource source, ExtendedTextSourceLabel oldLabel, int offset) {
    // currently no optimization.
    this.source = source;
    this.decorator = oldLabel.decorator;
    finishInit();
  }

  private void finishInit() {
    font = source.getFont();

    Map<TextAttribute, ?> atts = font.getAttributes();
    baseTX = AttributeValues.getBaselineTransform(atts);
    if (baseTX == null){
        cm = source.getCoreMetrics();
    } else {
      AffineTransform charTX = AttributeValues.getCharTransform(atts);
      if (charTX == null) {
          charTX = new AffineTransform();
      }
      font = font.deriveFont(charTX);

      LineMetrics lm = font.getLineMetrics(source.getChars(), source.getStart(),
          source.getStart() + source.getLength(), source.getFRC());
      cm = CoreMetrics.get(lm);
    }
  }


  // TextLabel API

  public Rectangle2D getLogicalBounds() {
    return getLogicalBounds(0, 0);
  }

  public Rectangle2D getLogicalBounds(float x, float y) {
    if (lb == null) {
      lb = createLogicalBounds();
    }
    return new Rectangle2D.Float((float)(lb.getX() + x),
                                 (float)(lb.getY() + y),
                                 (float)lb.getWidth(),
                                 (float)lb.getHeight());
  }

    public float getAdvance() {
        if (lb == null) {
            lb = createLogicalBounds();
        }
        return (float)lb.getWidth();
    }

  public Rectangle2D getVisualBounds(float x, float y) {
    if (vb == null) {
      vb = decorator.getVisualBounds(this);
    }
    return new Rectangle2D.Float((float)(vb.getX() + x),
                                 (float)(vb.getY() + y),
                                 (float)vb.getWidth(),
                                 (float)vb.getHeight());
  }

  public Rectangle2D getAlignBounds(float x, float y) {
    if (ab == null) {
      ab = createAlignBounds();
    }
    return new Rectangle2D.Float((float)(ab.getX() + x),
                                 (float)(ab.getY() + y),
                                 (float)ab.getWidth(),
                                 (float)ab.getHeight());

  }

  public Rectangle2D getItalicBounds(float x, float y) {
    if (ib == null) {
      ib = createItalicBounds();
    }
    return new Rectangle2D.Float((float)(ib.getX() + x),
                                 (float)(ib.getY() + y),
                                 (float)ib.getWidth(),
                                 (float)ib.getHeight());

  }

  public Rectangle getPixelBounds(FontRenderContext frc, float x, float y) {
      return getGV().getPixelBounds(frc, x, y);
  }

  public boolean isSimple() {
      return decorator == Decoration.getPlainDecoration() &&
             baseTX == null;
  }

  public AffineTransform getBaselineTransform() {
      return baseTX; // passing internal object, caller must not modify!
  }

  public Shape handleGetOutline(float x, float y) {
    return getGV().getOutline(x, y);
  }

  public Shape getOutline(float x, float y) {
    return decorator.getOutline(this, x, y);
  }

  public void handleDraw(Graphics2D g, float x, float y) {
    g.drawGlyphVector(getGV(), x, y);
  }

  public void draw(Graphics2D g, float x, float y) {
    decorator.drawTextAndDecorations(this, g, x, y);
  }

  
The logical bounds extends from the origin of the glyphvector to the
position at which a following glyphvector's origin should be placed.
We always assume glyph vectors are rendered from left to right, so
the origin is always to the left.
 On a left-to-right run, combining marks and 'ligatured away'
characters are to the right of their base characters.  The charinfo
array will record the character positions for these 'missing' characters
as being at the origin+advance of the base glyph, with zero advance.
(This is not necessarily the same as the glyph position, for example,
an umlaut glyph may have a position to the left of this point, it depends
on whether the font was designed so that such glyphs overhang to the left
of their origin, or whether it presumes some kind of kerning to position
the glyphs).  Anyway, the left of the bounds is the origin of the first
logical (leftmost) character, and the right is the origin + advance of the
last logical (rightmost) character.
 On a right-to-left run, these special characters are to the left
of their base characters.  Again, since 'glyph position' has been abstracted
away, we can use the origin of the leftmost character, and the origin +
advance of the rightmost character.
 On a mixed run (hindi) we can't rely on the first logical character
being the leftmost character.  However we can again rely on the leftmost
character origin and the rightmost character + advance.
/**
   * The logical bounds extends from the origin of the glyphvector to the
   * position at which a following glyphvector's origin should be placed.
   * We always assume glyph vectors are rendered from left to right, so
   * the origin is always to the left.
   * <p> On a left-to-right run, combining marks and 'ligatured away'
   * characters are to the right of their base characters.  The charinfo
   * array will record the character positions for these 'missing' characters
   * as being at the origin+advance of the base glyph, with zero advance.
   * (This is not necessarily the same as the glyph position, for example,
   * an umlaut glyph may have a position to the left of this point, it depends
   * on whether the font was designed so that such glyphs overhang to the left
   * of their origin, or whether it presumes some kind of kerning to position
   * the glyphs).  Anyway, the left of the bounds is the origin of the first
   * logical (leftmost) character, and the right is the origin + advance of the
   * last logical (rightmost) character.
   * <p> On a right-to-left run, these special characters are to the left
   * of their base characters.  Again, since 'glyph position' has been abstracted
   * away, we can use the origin of the leftmost character, and the origin +
   * advance of the rightmost character.
   * <p> On a mixed run (hindi) we can't rely on the first logical character
   * being the leftmost character.  However we can again rely on the leftmost
   * character origin and the rightmost character + advance.
   */
  protected Rectangle2D createLogicalBounds() {
    return getGV().getLogicalBounds();
  }

  public Rectangle2D handleGetVisualBounds() {
    return getGV().getVisualBounds();
  }

  
Like createLogicalBounds except ignore leading and logically trailing white space.
this assumes logically trailing whitespace is also visually trailing.
Whitespace is anything that has a zero visual width, regardless of its advance.
 We make the same simplifying assumptions as in createLogicalBounds, namely
that we can rely on the charinfo to shield us from any glyph positioning oddities
in the font that place the glyph for a character at other than the pos + advance
of the character to its left.  So we no longer need to skip chars with zero
advance, as their bounds (right and left) are already correct.
/**
   * Like createLogicalBounds except ignore leading and logically trailing white space.
   * this assumes logically trailing whitespace is also visually trailing.
   * Whitespace is anything that has a zero visual width, regardless of its advance.
   * <p> We make the same simplifying assumptions as in createLogicalBounds, namely
   * that we can rely on the charinfo to shield us from any glyph positioning oddities
   * in the font that place the glyph for a character at other than the pos + advance
   * of the character to its left.  So we no longer need to skip chars with zero
   * advance, as their bounds (right and left) are already correct.
   */
  protected Rectangle2D createAlignBounds() {
    float[] info = getCharinfo();

    float al = 0f;
    float at = -cm.ascent;
    float aw = 0f;
    float ah = cm.ascent + cm.descent;

    if (charinfo == null || charinfo.length == 0) {
        return new Rectangle2D.Float(al, at, aw, ah);
    }

    boolean lineIsLTR = (source.getLayoutFlags() & 0x8) == 0;
    int rn = info.length - numvals;
    if (lineIsLTR) {
      while (rn > 0 && info[rn+visw] == 0) {
        rn -= numvals;
      }
    }

    if (rn >= 0) {
      int ln = 0;
      while (ln < rn && ((info[ln+advx] == 0) || (!lineIsLTR && info[ln+visw] == 0))) {
        ln += numvals;
      }

      al = Math.max(0f, info[ln+posx]);
      aw = info[rn+posx] + info[rn+advx] - al;
    }

    /*
      boolean lineIsLTR = source.lineIsLTR();
      int rn = info.length - numvals;
      while (rn > 0 && ((info[rn+advx] == 0) || (lineIsLTR && info[rn+visw] == 0))) {
      rn -= numvals;
      }

      if (rn >= 0) {
      int ln = 0;
      while (ln < rn && ((info[ln+advx] == 0) || (!lineIsLTR && info[ln+visw] == 0))) {
      ln += numvals;
      }

      al = Math.max(0f, info[ln+posx]);
      aw = info[rn+posx] + info[rn+advx] - al;
      }
      */

    return new Rectangle2D.Float(al, at, aw, ah);
  }

  public Rectangle2D createItalicBounds() {
    float ia = cm.italicAngle;

    Rectangle2D lb = getLogicalBounds();
    float l = (float)lb.getMinX();
    float t = -cm.ascent;
    float r = (float)lb.getMaxX();
    float b = cm.descent;
    if (ia != 0) {
        if (ia > 0) {
            l -= ia * (b - cm.ssOffset);
            r -= ia * (t - cm.ssOffset);
        } else {
            l -= ia * (t - cm.ssOffset);
            r -= ia * (b - cm.ssOffset);
        }
    }
    return new Rectangle2D.Float(l, t, r - l, b - t);
  }

  private final StandardGlyphVector getGV() {
    if (gv == null) {
      gv = createGV();
    }

    return gv;
  }

  protected StandardGlyphVector createGV() {
    FontRenderContext frc = source.getFRC();
    int flags = source.getLayoutFlags();
    char[] context = source.getChars();
    int start = source.getStart();
    int length = source.getLength();

    GlyphLayout gl = GlyphLayout.get(null); // !!! no custom layout engines
    gv = gl.layout(font, frc, context, start, length, flags, null); // ??? use textsource
    GlyphLayout.done(gl);

    return gv;
  }

  // ExtendedTextLabel API

  private static final int posx = 0,
    posy = 1,
    advx = 2,
    advy = 3,
    visx = 4,
    visy = 5,
    visw = 6,
    vish = 7;
  private static final int numvals = 8;

  public int getNumCharacters() {
    return source.getLength();
  }

  public CoreMetrics getCoreMetrics() {
    return cm;
  }

  public float getCharX(int index) {
    validate(index);
    float[] charinfo = getCharinfo();
    int idx = l2v(index) * numvals + posx;
    if (charinfo == null || idx >= charinfo.length) {
        return 0f;
    } else {
        return charinfo[idx];
    }
  }

  public float getCharY(int index) {
    validate(index);
    float[] charinfo = getCharinfo();
    int idx = l2v(index) * numvals + posy;
    if (charinfo == null || idx >= charinfo.length) {
        return 0f;
    } else {
        return charinfo[idx];
    }
  }

  public float getCharAdvance(int index) {
    validate(index);
    float[] charinfo = getCharinfo();
    int idx = l2v(index) * numvals + advx;
    if (charinfo == null || idx >= charinfo.length) {
        return 0f;
    } else {
        return charinfo[idx];
    }
  }

  public Rectangle2D handleGetCharVisualBounds(int index) {
    validate(index);
    float[] charinfo = getCharinfo();
    index = l2v(index) * numvals;
    if (charinfo == null || (index+vish) >= charinfo.length) {
        return new Rectangle2D.Float();
    }
    return new Rectangle2D.Float(
                                 charinfo[index + visx],
                                 charinfo[index + visy],
                                 charinfo[index + visw],
                                 charinfo[index + vish]);
  }

  public Rectangle2D getCharVisualBounds(int index, float x, float y) {

    Rectangle2D bounds = decorator.getCharVisualBounds(this, index);
    if (x != 0 || y != 0) {
        bounds.setRect(bounds.getX()+x,
                       bounds.getY()+y,
                       bounds.getWidth(),
                       bounds.getHeight());
    }
    return bounds;
  }

  private void validate(int index) {
    if (index < 0) {
      throw new IllegalArgumentException("index " + index + " < 0");
    } else if (index >= source.getLength()) {
      throw new IllegalArgumentException("index " + index + " < " + source.getLength());
    }
  }

  /*
    public int hitTestChar(float x, float y) {
    // !!! return index of char hit, for swing
    // result is negative for trailing-edge hits
    // no italics so no problem at margins.
    // for now, ignore y since we assume horizontal text

    // find non-combining char origin to right of x
    float[] charinfo = getCharinfo();

    int n = 0;
    int e = source.getLength();
    while (n < e && charinfo[n + advx] != 0 && charinfo[n + posx] > x) {
    n += numvals;
    }
    float rightx = n < e ? charinfo[n+posx] : charinfo[e - numvals + posx] + charinfo[e - numvals + advx];

    // find non-combining char to left of that char
    n -= numvals;
    while (n >= 0 && charinfo[n+advx] == 0) {
    n -= numvals;
    }
    float leftx = n >= 0 ? charinfo[n+posx] : 0;
    float lefta = n >= 0 ? charinfo[n+advx] : 0;

    n /= numvals;

    boolean left = true;
    if (x < leftx + lefta / 2f) {
    // left of prev char
    } else if (x < (leftx + lefta + rightx) / 2f) {
    // right of prev char
    left = false;
    } else {
    // left of follow char
    n += 1;
    }

    if ((source.getLayoutFlags() & 0x1) != 0) {
    n = getNumCharacters() - 1 - n;
    left = !left;
    }

    return left ? n : -n;
    }
    */

  public int logicalToVisual(int logicalIndex) {
    validate(logicalIndex);
    return l2v(logicalIndex);
  }

  public int visualToLogical(int visualIndex) {
    validate(visualIndex);
    return v2l(visualIndex);
  }

  public int getLineBreakIndex(int start, float width) {
    float[] charinfo = getCharinfo();
    int length = source.getLength();
    --start;
    while (width >= 0 && ++start < length) {
      int cidx = l2v(start) * numvals + advx;
      if (cidx >= charinfo.length) {
          break; // layout bailed for some reason
      }
      float adv = charinfo[cidx];
      width -= adv;
    }

    return start;
  }

  public float getAdvanceBetween(int start, int limit) {
    float a = 0f;

    float[] charinfo = getCharinfo();
    --start;
    while (++start < limit) {
      int cidx = l2v(start) * numvals + advx;
      if (cidx >= charinfo.length) {
          break; // layout bailed for some reason
      }
      a += charinfo[cidx];
    }

    return a;
  }

  public boolean caretAtOffsetIsValid(int offset) {
      // REMIND: improve this implementation

      // Ligature formation can either be done in logical order,
      // with the ligature glyph logically preceding the null
      // chars;  or in visual order, with the ligature glyph to
      // the left of the null chars.  This method's implementation
      // must reflect which strategy is used.

      if (offset == 0 || offset == source.getLength()) {
          return true;
      }
      char c = source.getChars()[source.getStart() + offset];
      if (c == '\t' || c == '\n' || c == '\r') { // hack
          return true;
      }
      int v = l2v(offset);

      // If ligatures are always to the left, do this stuff:
      //if (!(source.getLayoutFlags() & 0x1) == 0) {
      //    v += 1;
      //    if (v == source.getLength()) {
      //        return true;
      //    }
      //}

      int idx = v * numvals + advx;
      float[] charinfo = getCharinfo();
      if (charinfo == null || idx >= charinfo.length) {
          return false;
      } else {
          return charinfo[idx] != 0;
      }
  }

  private final float[] getCharinfo() {
    if (charinfo == null) {
      charinfo = createCharinfo();
    }
    return charinfo;
  }

  private static final boolean DEBUG = FontUtilities.debugFonts();
/*
* This takes the glyph info record obtained from the glyph vector and converts it into a similar record
* adjusted to represent character data instead.  For economy we don't use glyph info records in this processing.
*
* Here are some constraints:
* - there can be more glyphs than characters (glyph insertion, perhaps based on normalization, has taken place)
* - there can be fewer glyphs than characters
*   Some layout engines may insert 0xffff glyphs for characters ligaturized away, but
*   not all do, and it cannot be relied upon.
* - each glyph maps to a single character, when multiple glyphs exist for a character they all map to it, but
*   no two characters map to the same glyph
* - multiple glyphs mapping to the same character need not be in sequence (thai, tamil have split characters)
* - glyphs may be arbitrarily reordered (Indic reorders glyphs)
* - all glyphs share the same bidi level
* - all glyphs share the same horizontal (or vertical) baseline
* - combining marks visually follow their base character in the glyph array-- i.e. in an rtl gv they are
*   to the left of their base character-- and have zero advance.
*
* The output maps this to character positions, and therefore caret positions, via the following assumptions:
* - zero-advance glyphs do not contribute to the advance of their character (i.e. position is ignored), conversely
*   if a glyph is to contribute to the advance of its character it must have a non-zero (float) advance
* - no carets can appear between a zero width character and its preceding character, where 'preceding' is
*   defined logically.
* - no carets can appear within a split character
* - no carets can appear within a local reordering (i.e. Indic reordering, or non-adjacent split characters)
* - all characters lie on the same baseline, and it is either horizontal or vertical
* - the charinfo is in uniform ltr or rtl order (visual order), since local reorderings and split characters are removed
*
* The algorithm works in the following way:
* 1) we scan the glyphs ltr or rtl based on the bidi run direction
* 2) Since the may be fewer glyphs than chars we cannot work in place.
*    A new array is allocated for output.
*    a) if the line is ltr, we start writing at position 0 until we finish, there may be leftver space
*    b) if the line is rtl and 1-1, we start writing at position numChars/glyphs - 1 until we finish at 0
*    c) otherwise if we don't finish at 0, we have to copy the data down
* 3) we consume clusters in the following way:
*    a) the first element is always consumed
*    b) subsequent elements are consumed if:
*       i) their advance is zero
*       ii) their character index <= the character index of any character seen in this cluster
*       iii) the minimum character index seen in this cluster isn't adjacent to the previous cluster
*    c) character data is written as follows for horizontal lines (x/y and w/h are exchanged on vertical lines)
*       i) the x position is the position of the leftmost glyph whose advance is not zero
*       ii)the y position is the baseline
*       iii) the x advance is the distance to the maximum x + adv of all glyphs whose advance is not zero
*       iv) the y advance is the baseline
*       v) vis x,y,w,h tightly encloses the vis x,y,w,h of all the glyphs with nonzero w and h
* 4) In the future, we can make some simple optimizations to avoid copying if we know some things:
*    a) if the mapping is 1-1, unidirectional, and there are no zero-adv glyphs, we just return the glyphinfo
*    b) if the mapping is 1-1, unidirectional, we just adjust the remaining glyphs to originate at right/left of the base
*    c) if the mapping is 1-1, we compute the base position and advance as we go, then go back to adjust the remaining glyphs
*    d) otherwise we keep separate track of the write position as we do (c) since no glyph in the cluster may be in the
*    position we are writing.
*    e) most clusters are simply the single base glyph in the same position as its character, so we try to avoid
*    copying its data unnecessarily.
* 5) the glyph vector ought to provide access to these 'global' attributes to enable these optimizations.  A single
*    int with flags set is probably ok, we could also provide accessors for each attribute.  This doesn't map to
*    the GlyphMetrics flags very well, so I won't attempt to keep them similar.  It might be useful to add those
*    in addition to these.
*    int FLAG_HAS_ZERO_ADVANCE_GLYPHS = 1; // set if there are zero-advance glyphs
*    int FLAG_HAS_NONUNIFORM_ORDER = 2; // set if some glyphs are rearranged out of character visual order
*    int FLAG_HAS_SPLIT_CHARACTERS = 4; // set if multiple glyphs per character
*    int getDescriptionFlags(); // return an int containing the above flags
*    boolean hasZeroAdvanceGlyphs();
*    boolean hasNonuniformOrder();
*    boolean hasSplitCharacters();
*    The optimized cases in (4) correspond to values 0, 1, 3, and 7 returned by getDescriptionFlags().
*/
  protected float[] createCharinfo() {
    StandardGlyphVector gv = getGV();
    float[] glyphinfo = null;
    try {
        glyphinfo = gv.getGlyphInfo();
    }
    catch (Exception e) {
        if (DEBUG) {
            System.err.println(source);
            e.printStackTrace();
        }
        glyphinfo = new float[gv.getNumGlyphs() * numvals];
    }

    int numGlyphs = gv.getNumGlyphs();
    if (numGlyphs == 0) {
        return glyphinfo;
    }
    int[] indices = gv.getGlyphCharIndices(0, numGlyphs, null);
    float[] charInfo = new float[source.getLength() * numvals];

    if (DEBUG) {
      System.err.println("number of glyphs: " + numGlyphs);
      System.err.println("glyphinfo.len: " + glyphinfo.length);
      System.err.println("indices.len: " + indices.length);
      for (int i = 0; i < numGlyphs; ++i) {
        System.err.println("g: " + i +
            "  v: " + gv.getGlyphCode(i) +
            ", x: " + glyphinfo[i*numvals+posx] +
            ", a: " + glyphinfo[i*numvals+advx] +
            ", n: " + indices[i]);
      }
    }

    int minIndex = indices[0];  // smallest index seen this cluster
    int maxIndex = minIndex;    // largest index seen this cluster
    int cp = 0;                 // character position
    int cc = 0;
    int gp = 0;                 // glyph position
    int gx = 0;                 // glyph index (visual)
    int gxlimit = numGlyphs;    // limit of gx, when we reach this we're done
    int pdelta = numvals;       // delta for incrementing positions
    int xdelta = 1;             // delta for incrementing indices

    boolean rtl = (source.getLayoutFlags() & 0x1) == 1;
    if (rtl) {
        minIndex = indices[numGlyphs - 1];
        maxIndex = minIndex;
        cp = charInfo.length - numvals;
        gp = glyphinfo.length - numvals;
        gx = numGlyphs - 1;
        gxlimit = -1;
        pdelta = -numvals;
        xdelta = -1;
    }

    /*
    // to support vertical, use 'ixxxx' indices and swap horiz and vertical components
    if (source.isVertical()) {
        iposx = posy;
        iposy = posx;
        iadvx = advy;
        iadvy = advx;
        ivisx = visy;
        ivisy = visx;
        ivish = visw;
        ivisw = vish;
    } else {
        // use standard values
    }
    */

    // use intermediates to reduce array access when we need to
    float cposl = 0, cposr = 0, cvisl = 0, cvist = 0, cvisr = 0, cvisb = 0;
    float baseline = 0;

    while (gx != gxlimit) {
        // start of new cluster
        int clusterExtraGlyphs = 0;

        minIndex = indices[gx];
        maxIndex = minIndex;

        cposl = glyphinfo[gp + posx];
        cposr = cposl + glyphinfo[gp + advx];
        cvisl = glyphinfo[gp + visx];
        cvist = glyphinfo[gp + visy];
        cvisr = cvisl + glyphinfo[gp + visw];
        cvisb = cvist + glyphinfo[gp + vish];

        // advance to next glyph
        gx += xdelta;
        gp += pdelta;

        while (gx != gxlimit &&
               ((glyphinfo[gp + advx] == 0) ||
               (indices[gx] <= maxIndex) ||
               (maxIndex - minIndex > clusterExtraGlyphs))) {

            ++clusterExtraGlyphs; // have an extra glyph in this cluster
            if (DEBUG) {
                System.err.println("gp=" +gp +" adv=" + glyphinfo[gp + advx] +
                                   " gx="+ gx+ " i[gx]="+indices[gx] +
                                   " clusterExtraGlyphs="+clusterExtraGlyphs);
            }

            // adjust advance only if new glyph has non-zero advance
            float radvx = glyphinfo[gp + advx];
            if (radvx != 0) {
                float rposx = glyphinfo[gp + posx];
                cposl = Math.min(cposl, rposx);
                cposr = Math.max(cposr, rposx + radvx);
            }

            // adjust visible bounds only if new glyph has non-empty bounds
            float rvisw = glyphinfo[gp + visw];
            if (rvisw != 0) {
                float rvisx = glyphinfo[gp + visx];
                float rvisy = glyphinfo[gp + visy];
                cvisl = Math.min(cvisl, rvisx);
                cvist = Math.min(cvist, rvisy);
                cvisr = Math.max(cvisr, rvisx + rvisw);
                cvisb = Math.max(cvisb, rvisy + glyphinfo[gp + vish]);
            }

            // adjust min, max index
            minIndex = Math.min(minIndex, indices[gx]);
            maxIndex = Math.max(maxIndex, indices[gx]);

            // get ready to examine next glyph
            gx += xdelta;
            gp += pdelta;
        }
        // done with cluster, gx and gp are set for next glyph

        if (DEBUG) {
            System.err.println("minIndex = " + minIndex + ", maxIndex = " + maxIndex);
        }

        // save adjustments to the base character and do common adjustments.
        charInfo[cp + posx] = cposl;
        charInfo[cp + posy] = baseline;
        charInfo[cp + advx] = cposr - cposl;
        charInfo[cp + advy] = 0;
        charInfo[cp + visx] = cvisl;
        charInfo[cp + visy] = cvist;
        charInfo[cp + visw] = cvisr - cvisl;
        charInfo[cp + vish] = cvisb - cvist;
        cc++;

        /* We may have consumed multiple glyphs for this char position.
         * Map those extra consumed glyphs to char positions that would follow
         * up to the index prior to that which begins the next cluster.
         * If we have reached the last glyph (reached gxlimit) then we need to
         * map remaining unmapped chars to the same location as the last one.
         */
        int tgt;
        if (gx == gxlimit) {
           tgt = charInfo.length / numvals;
        } else {
           tgt = indices[gx];
        }
        if (DEBUG) {
           System.err.println("gx=" + gx + " gxlimit=" + gxlimit +
                              " charInfo.len=" + charInfo.length +
                              " tgt=" + tgt + " cc=" + cc + " cp=" + cp);
        }
        while (cc < tgt) {
            if (rtl) {
                // if rtl, characters to left of base, else to right.  reuse cposr.
                cposr = cposl;
            }
            cvisr -= cvisl; // reuse, convert to deltas.
            cvisb -= cvist;

            cp += pdelta;

            if (cp < 0 || cp >= charInfo.length) {
                if (DEBUG)  {
                    System.err.println("Error : cp=" + cp +
                                       " charInfo.length=" + charInfo.length);
                }
                break;
            }

            if (DEBUG) {
                System.err.println("Insert charIndex " + cc + " at pos="+cp);
            }
            charInfo[cp + posx] = cposr;
            charInfo[cp + posy] = baseline;
            charInfo[cp + advx] = 0;
            charInfo[cp + advy] = 0;
            charInfo[cp + visx] = cvisl;
            charInfo[cp + visy] = cvist;
            charInfo[cp + visw] = cvisr;
            charInfo[cp + vish] = cvisb;
            cc++;
        }
        cp += pdelta; // reset for new cluster
    }

    if (DEBUG) {
        char[] chars = source.getChars();
        int start = source.getStart();
        int length = source.getLength();
        System.err.println("char info for " + length + " characters");

        for (int i = 0; i < length * numvals;) {
            System.err.println(" ch: " + Integer.toHexString(chars[start + v2l(i / numvals)]) +
                               " x: " + charInfo[i++] +
                               " y: " + charInfo[i++] +
                               " xa: " + charInfo[i++] +
                               " ya: " + charInfo[i++] +
                               " l: " + charInfo[i++] +
                               " t: " + charInfo[i++] +
                               " w: " + charInfo[i++] +
                               " h: " + charInfo[i++]);
      }
    }
    return charInfo;
  }

  
Map logical character index to visual character index.

This ignores hindi reordering.  @see createCharinfo
/**
   * Map logical character index to visual character index.
   * <p>
   * This ignores hindi reordering.  @see createCharinfo
   */
  protected int l2v(int index) {
    return (source.getLayoutFlags() & 0x1) == 0 ? index : source.getLength() - 1 - index;
  }

  
Map visual character index to logical character index.

This ignores hindi reordering.  @see createCharinfo
/**
   * Map visual character index to logical character index.
   * <p>
   * This ignores hindi reordering.  @see createCharinfo
   */
  protected int v2l(int index) {
    return (source.getLayoutFlags() & 0x1) == 0 ? index : source.getLength() - 1 - index;
  }

  public TextLineComponent getSubset(int start, int limit, int dir) {
    return new ExtendedTextSourceLabel(source.getSubSource(start, limit-start, dir), decorator);
  }

  public String toString() {
    if (true) {
        return source.toString(TextSource.WITHOUT_CONTEXT);
    }
    StringBuilder sb = new StringBuilder();
    sb.append(super.toString());
    sb.append("[source:");
    sb.append(source.toString(TextSource.WITHOUT_CONTEXT));
    sb.append(", lb:");
    sb.append(lb);
    sb.append(", ab:");
    sb.append(ab);
    sb.append(", vb:");
    sb.append(vb);
    sb.append(", gv:");
    sb.append(gv);
    sb.append(", ci: ");
    if (charinfo == null) {
      sb.append("null");
    } else {
      sb.append(charinfo[0]);
      for (int i = 1; i < charinfo.length;) {
        sb.append(i % numvals == 0 ? "; " : ", ");
        sb.append(charinfo[i]);
      }
    }
    sb.append("]");

    return sb.toString();
  }

  //public static ExtendedTextLabel create(TextSource source) {
  //  return new ExtendedTextSourceLabel(source);
  //}

  public int getNumJustificationInfos() {
    return getGV().getNumGlyphs();
  }


  public void getJustificationInfos(GlyphJustificationInfo[] infos, int infoStart, int charStart, int charLimit) {
    // This simple implementation only uses spaces for justification.
    // Since regular characters aren't justified, we don't need to deal with
    // special infos for combining marks or ligature substitution glyphs.
    // added character justification for kanjii only 2/22/98

    StandardGlyphVector gv = getGV();

    float[] charinfo = getCharinfo();

    float size = gv.getFont().getSize2D();

    GlyphJustificationInfo nullInfo =
      new GlyphJustificationInfo(0,
                                 false, GlyphJustificationInfo.PRIORITY_NONE, 0, 0,
                                 false, GlyphJustificationInfo.PRIORITY_NONE, 0, 0);

    GlyphJustificationInfo spaceInfo =
      new GlyphJustificationInfo(size,
                                 true, GlyphJustificationInfo.PRIORITY_WHITESPACE, 0, size,
                                 true, GlyphJustificationInfo.PRIORITY_WHITESPACE, 0, size / 4f);

    GlyphJustificationInfo kanjiInfo =
      new GlyphJustificationInfo(size,
                                 true, GlyphJustificationInfo.PRIORITY_INTERCHAR, size, size,
                                 false, GlyphJustificationInfo.PRIORITY_NONE, 0, 0);

    char[] chars = source.getChars();
    int offset = source.getStart();

    // assume data is 1-1 and either all rtl or all ltr, for now

    int numGlyphs = gv.getNumGlyphs();
    int minGlyph = 0;
    int maxGlyph = numGlyphs;
    boolean ltr = (source.getLayoutFlags() & 0x1) == 0;
    if (charStart != 0 || charLimit != source.getLength()) {
      if (ltr) {
        minGlyph = charStart;
        maxGlyph = charLimit;
      } else {
        minGlyph = numGlyphs - charLimit;
        maxGlyph = numGlyphs - charStart;
      }
    }

    for (int i = 0; i < numGlyphs; ++i) {
      GlyphJustificationInfo info = null;
      if (i >= minGlyph && i < maxGlyph) {
        if (charinfo[i * numvals + advx] == 0) { // combining marks don't justify
          info = nullInfo;
        } else {
          int ci = v2l(i); // 1-1 assumption again
          char c = chars[offset + ci];
          if (Character.isWhitespace(c)) {
            info = spaceInfo;
            // CJK, Hangul, CJK Compatibility areas
          } else if (c >= 0x4e00 &&
                     (c < 0xa000) ||
                     (c >= 0xac00 && c < 0xd7b0) ||
                     (c >= 0xf900 && c < 0xfb00)) {
            info = kanjiInfo;
          } else {
            info = nullInfo;
          }
        }
      }
      infos[infoStart + i] = info;
    }
  }

  public TextLineComponent applyJustificationDeltas(float[] deltas, int deltaStart, boolean[] flags) {

    // when we justify, we need to adjust the charinfo since spaces
    // change their advances.  preserve the existing charinfo.

    float[] newCharinfo = getCharinfo().clone();

    // we only push spaces, so never need to rejustify
    flags[0] = false;

    // preserve the existing gv.

    StandardGlyphVector newgv = (StandardGlyphVector)getGV().clone();
    float[] newPositions = newgv.getGlyphPositions(null);
    int numGlyphs = newgv.getNumGlyphs();

    /*
    System.out.println("oldgv: " + getGV() + ", newgv: " + newgv);
    System.out.println("newpositions: " + newPositions);
    for (int i = 0; i < newPositions.length; i += 2) {
      System.out.println("[" + (i/2) + "] " + newPositions[i] + ", " + newPositions[i+1]);
    }

    System.out.println("deltas: " + deltas + " start: " + deltaStart);
    for (int i = deltaStart; i < deltaStart + numGlyphs; i += 2) {
      System.out.println("[" + (i/2) + "] " + deltas[i] + ", " + deltas[i+1]);
    }
    */

    char[] chars = source.getChars();
    int offset = source.getStart();

    // accumulate the deltas to adjust positions and advances.
    // handle whitespace by modifying advance,
    // handle everything else by modifying position before and after

    float deltaPos = 0;
    for (int i = 0; i < numGlyphs; ++i) {
      if (Character.isWhitespace(chars[offset + v2l(i)])) {
        newPositions[i*2] += deltaPos;

        float deltaAdv = deltas[deltaStart + i*2] + deltas[deltaStart + i*2 + 1];

        newCharinfo[i * numvals + posx] += deltaPos;
        newCharinfo[i * numvals + visx] += deltaPos;
        newCharinfo[i * numvals + advx] += deltaAdv;

        deltaPos += deltaAdv;
      } else {
        deltaPos += deltas[deltaStart + i*2];

        newPositions[i*2] += deltaPos;
        newCharinfo[i * numvals + posx] += deltaPos;
        newCharinfo[i * numvals + visx] += deltaPos;

        deltaPos += deltas[deltaStart + i*2 + 1];
      }
    }
    newPositions[numGlyphs * 2] += deltaPos;

    newgv.setGlyphPositions(newPositions);

    /*
    newPositions = newgv.getGlyphPositions(null);
    System.out.println(">> newpositions: " + newPositions);
    for (int i = 0; i < newPositions.length; i += 2) {
      System.out.println("[" + (i/2) + "] " + newPositions[i] + ", " + newPositions[i+1]);
    }
    */

    ExtendedTextSourceLabel result = new ExtendedTextSourceLabel(source, decorator);
    result.gv = newgv;
    result.charinfo = newCharinfo;

    return result;
  }
}