org.apache.fontbox.ttf.GlyfSimpleDescript Maven / Gradle / Ivy
/*
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.
*/
package org.apache.fontbox.ttf;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* This class is based on code from Apache Batik a subproject of Apache XMLGraphics. see
* http://xmlgraphics.apache.org/batik/ for further details.
*/
public class GlyfSimpleDescript extends GlyfDescript
{
/**
* Log instance.
*/
private static final Log LOG = LogFactory.getLog(GlyfSimpleDescript.class);
private int[] endPtsOfContours;
private byte[] flags;
private short[] xCoordinates;
private short[] yCoordinates;
private final int pointCount;
/**
* Constructor.
*
* @param numberOfContours number of contours
* @param bais the stream to be read
* @param x0 the initial X-position
* @throws IOException is thrown if something went wrong
*/
GlyfSimpleDescript(short numberOfContours, TTFDataStream bais, short x0) throws IOException
{
super(numberOfContours, bais);
/*
* https://developer.apple.com/fonts/TTRefMan/RM06/Chap6glyf.html
* "If a glyph has zero contours, it need not have any glyph data." set the pointCount to zero to initialize
* attributes and avoid nullpointer but maybe there shouldn't have GlyphDescript in the GlyphData?
*/
if (numberOfContours == 0)
{
pointCount = 0;
return;
}
// Simple glyph description
endPtsOfContours = bais.readUnsignedShortArray(numberOfContours);
int lastEndPt = endPtsOfContours[numberOfContours - 1];
if (numberOfContours == 1 && lastEndPt == 65535)
{
// PDFBOX-2939: assume an empty glyph
pointCount = 0;
return;
}
// The last end point index reveals the total number of points
pointCount = lastEndPt + 1;
flags = new byte[pointCount];
xCoordinates = new short[pointCount];
yCoordinates = new short[pointCount];
int instructionCount = bais.readUnsignedShort();
readInstructions(bais, instructionCount);
readFlags(pointCount, bais);
readCoords(pointCount, bais, x0);
}
/**
* {@inheritDoc}
*/
@Override
public int getEndPtOfContours(int i)
{
return endPtsOfContours[i];
}
/**
* {@inheritDoc}
*/
@Override
public byte getFlags(int i)
{
return flags[i];
}
/**
* {@inheritDoc}
*/
@Override
public short getXCoordinate(int i)
{
return xCoordinates[i];
}
/**
* {@inheritDoc}
*/
@Override
public short getYCoordinate(int i)
{
return yCoordinates[i];
}
/**
* {@inheritDoc}
*/
@Override
public boolean isComposite()
{
return false;
}
/**
* {@inheritDoc}
*/
@Override
public int getPointCount()
{
return pointCount;
}
/**
* The table is stored as relative values, but we'll store them as absolutes.
*/
private void readCoords(int count, TTFDataStream bais, short x0) throws IOException
{
short x = x0;
short y = 0;
for (int i = 0; i < count; i++)
{
if ((flags[i] & X_DUAL) != 0)
{
if ((flags[i] & X_SHORT_VECTOR) != 0)
{
x += (short) bais.readUnsignedByte();
}
}
else
{
if ((flags[i] & X_SHORT_VECTOR) != 0)
{
x += (short) -((short) bais.readUnsignedByte());
}
else
{
x += bais.readSignedShort();
}
}
xCoordinates[i] = x;
}
for (int i = 0; i < count; i++)
{
if ((flags[i] & Y_DUAL) != 0)
{
if ((flags[i] & Y_SHORT_VECTOR) != 0)
{
y += (short) bais.readUnsignedByte();
}
}
else
{
if ((flags[i] & Y_SHORT_VECTOR) != 0)
{
y += (short) -((short) bais.readUnsignedByte());
}
else
{
y += bais.readSignedShort();
}
}
yCoordinates[i] = y;
}
}
/**
* The flags are run-length encoded.
*/
private void readFlags(int flagCount, TTFDataStream bais) throws IOException
{
for (int index = 0; index < flagCount; index++)
{
flags[index] = (byte) bais.readUnsignedByte();
if ((flags[index] & REPEAT) != 0)
{
int repeats = bais.readUnsignedByte();
for (int i = 1; i <= repeats && index + i < flags.length; i++)
{
flags[index + i] = flags[index];
}
index += repeats;
}
}
}
}