org.apache.pdfbox.pdmodel.graphics.shading.Type4ShadingContext Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
/*
* 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.pdfbox.pdmodel.graphics.shading;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.image.ColorModel;
import java.io.EOFException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.MemoryCacheImageInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.pdmodel.common.PDRange;
import org.apache.pdfbox.util.Matrix;
/**
* AWT PaintContext for Gouraud Triangle Mesh (Type 4) shading.
*
* @author Tilman Hausherr
* @author Shaola Ren
*/
class Type4ShadingContext extends GouraudShadingContext
{
private static final Log LOG = LogFactory.getLog(Type4ShadingContext.class);
private final int bitsPerFlag;
/**
* Constructor creates an instance to be used for fill operations.
*
* @param shading the shading type to be used
* @param cm the color model to be used
* @param xform transformation for user to device space
* @param matrix the pattern matrix concatenated with that of the parent content stream
*/
Type4ShadingContext(PDShadingType4 shading, ColorModel cm, AffineTransform xform,
Matrix matrix, Rectangle deviceBounds) throws IOException
{
super(shading, cm, xform, matrix);
LOG.debug("Type4ShadingContext");
bitsPerFlag = shading.getBitsPerFlag();
//TODO handle cases where bitperflag isn't 8
LOG.debug("bitsPerFlag: " + bitsPerFlag);
setTriangleList(collectTriangles(shading, xform, matrix));
createPixelTable(deviceBounds);
}
private List collectTriangles(PDShadingType4 freeTriangleShadingType, AffineTransform xform, Matrix matrix)
throws IOException
{
COSDictionary dict = freeTriangleShadingType.getCOSObject();
PDRange rangeX = freeTriangleShadingType.getDecodeForParameter(0);
PDRange rangeY = freeTriangleShadingType.getDecodeForParameter(1);
PDRange[] colRange = new PDRange[numberOfColorComponents];
for (int i = 0; i < numberOfColorComponents; ++i)
{
colRange[i] = freeTriangleShadingType.getDecodeForParameter(2 + i);
}
List list = new ArrayList();
long maxSrcCoord = (long) Math.pow(2, bitsPerCoordinate) - 1;
long maxSrcColor = (long) Math.pow(2, bitsPerColorComponent) - 1;
COSStream stream = (COSStream) dict;
ImageInputStream mciis = new MemoryCacheImageInputStream(stream.createInputStream());
try
{
byte flag = (byte) 0;
try
{
flag = (byte) (mciis.readBits(bitsPerFlag) & 3);
}
catch (EOFException ex)
{
LOG.error(ex);
}
while (true)
{
Vertex p0, p1, p2;
Point2D[] ps;
float[][] cs;
int lastIndex;
try
{
switch (flag)
{
case 0:
p0 = readVertex(mciis, maxSrcCoord, maxSrcColor, rangeX, rangeY, colRange,
matrix, xform);
flag = (byte) (mciis.readBits(bitsPerFlag) & 3);
if (flag != 0)
{
LOG.error("bad triangle: " + flag);
}
p1 = readVertex(mciis, maxSrcCoord, maxSrcColor, rangeX, rangeY, colRange,
matrix, xform);
mciis.readBits(bitsPerFlag);
if (flag != 0)
{
LOG.error("bad triangle: " + flag);
}
p2 = readVertex(mciis, maxSrcCoord, maxSrcColor, rangeX, rangeY, colRange,
matrix, xform);
ps = new Point2D[] { p0.point, p1.point, p2.point };
cs = new float[][] { p0.color, p1.color, p2.color };
list.add(new ShadedTriangle(ps, cs));
flag = (byte) (mciis.readBits(bitsPerFlag) & 3);
break;
case 1:
case 2:
lastIndex = list.size() - 1;
if (lastIndex < 0)
{
LOG.error("broken data stream: " + list.size());
}
else
{
ShadedTriangle preTri = list.get(lastIndex);
p2 = readVertex(mciis, maxSrcCoord, maxSrcColor, rangeX, rangeY,
colRange, matrix, xform);
ps = new Point2D[] { flag == 1 ? preTri.corner[1] : preTri.corner[0],
preTri.corner[2],
p2.point };
cs = new float[][] { flag == 1 ? preTri.color[1] : preTri.color[0],
preTri.color[2],
p2.color };
list.add(new ShadedTriangle(ps, cs));
flag = (byte) (mciis.readBits(bitsPerFlag) & 3);
}
break;
default:
LOG.warn("bad flag: " + flag);
break;
}
}
catch (EOFException ex)
{
break;
}
}
}
finally
{
mciis.close();
}
return list;
}
}