org.jpedal.fonts.tt.Hmtx Maven / Gradle / Ivy

/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2017 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
     This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


 *
 * ---------------
 * Hmtx.java
 * ---------------
 */
package org.jpedal.fonts.tt;

import org.jpedal.utils.LogWriter;


public class Hmtx extends Table {

    private int[] hMetrics;
    private short[] leftSideBearing;
    private float scaling = 1f / 1000f;

    public Hmtx(final FontFile2 currentFontFile, final int glyphCount, int metricsCount, final int maxAdvance) {

        scaling = maxAdvance;

        if (metricsCount < 0) {
            metricsCount = -metricsCount;
        }

        //move to start and check exists
        final int startPointer = currentFontFile.selectTable(FontFile2.HMTX);

        int lsbCount = glyphCount - metricsCount;

        //System.out.println("start="+Integer.toHexString(startPointer)+" lsbCount="+lsbCount+" glyphCount="+glyphCount+" metricsCount="+metricsCount);

        hMetrics = new int[glyphCount];
        leftSideBearing = new short[glyphCount];

        int currentMetric = 0;

        //read 'head' table
        if (startPointer == 0) {
            LogWriter.writeLog("No Htmx table found");
        } else if (lsbCount < 0) {
            LogWriter.writeLog("Invalid Htmx table found");
        } else {
            int i;
            for (i = 0; i < metricsCount; i++) {
                currentMetric = currentFontFile.getNextUint16();
                hMetrics[i] = currentMetric;
                leftSideBearing[i] = currentFontFile.getNextInt16();
                //System.out.println(i+"="+hMetrics[i]+" "+leftSideBearing[i]);
            }

            //workout actual number of values in table
            final int tableLength = currentFontFile.getTableSize(FontFile2.HMTX);
            final int lsbBytes = tableLength - (i * 4); //each entry above used 4 bytes
            lsbCount = (lsbBytes / 2); //each entry contains 2 bytes

            //catch needed for 48789.pdf
            try {
                //read additional lsb entries
                for (int j = i; j < lsbCount; j++) {

                    hMetrics[j] = currentMetric;
                    leftSideBearing[j] = currentFontFile.getFWord();
                    //System.out.println((j)+" "+leftSideBearing[j]);
                }
            } catch (final Exception ee) {
                LogWriter.writeLog("Exception in reading Hmtx " + ee);
            }
        }
    }

    public Hmtx() {
    }

    //used by OTF code for aligning CFF font data
    @SuppressWarnings("UnusedDeclaration")
    public short getRAWLSB(final int i) {
        if (leftSideBearing == null || i >= leftSideBearing.length) {
            return 0;
        } else {
            return leftSideBearing[i];
        }
    }

    public short getLeftSideBearing(final int i) {

        final int length = hMetrics.length;

        if (i < length) {
            return (short) (hMetrics[i] & 0xffff);
        } else if (leftSideBearing == null) {
            return 0;
        } else {

            final int ptr = i - length;
            if (ptr >= 0 && ptr < leftSideBearing.length) {
                return leftSideBearing[i - hMetrics.length];
            } else {
                return 0;
            }
        }
    }

    @SuppressWarnings("UnusedDeclaration")
    public float getAdvanceWidth(final int i) {
        /*if (i < hMetrics.length) {
            return hMetrics[i] >> 16;
		} else {
			return hMetrics[hMetrics.length - 1] >> 16;
		}*/
        return ((hMetrics[i] - getLeftSideBearing(i)) / scaling);
    }

    public float getWidth(final int i) {
        /* if (i < hMetrics.length) {
			return hMetrics[i] >> 16;
		} else {
			return hMetrics[hMetrics.length - 1] >> 16;
		}*/
        final float w = hMetrics[i];


        return ((w) / scaling);
    }

    public float getUnscaledWidth(final int i) {

        return hMetrics[i];
    }
}