org.apache.pdfbox.pdmodel.graphics.shading.Type5ShadingContext Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
There is a newer version: 3.0.2
/*
 * 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 Lattice (Type 5) shading.
 *
 * @author Tilman Hausherr
 * @author Shaola Ren
 */
class Type5ShadingContext extends GouraudShadingContext
{
    private static final Log LOG = LogFactory.getLog(Type5ShadingContext.class);

    /**
     * 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
     * @throws IOException if something went wrong
     */
    Type5ShadingContext(PDShadingType5 shading, ColorModel cm, AffineTransform xform,
                               Matrix matrix, Rectangle deviceBounds) throws IOException
    {
        super(shading, cm, xform, matrix);

        LOG.debug("Type5ShadingContext");

        setTriangleList(collectTriangles(shading, xform, matrix));
        createPixelTable(deviceBounds);
    }

    private List collectTriangles(PDShadingType5 latticeTriangleShadingType,
            AffineTransform xform, Matrix matrix) throws IOException
    {
        COSDictionary cosDictionary = latticeTriangleShadingType.getCOSObject();
        PDRange rangeX = latticeTriangleShadingType.getDecodeForParameter(0);
        PDRange rangeY = latticeTriangleShadingType.getDecodeForParameter(1);
        int numPerRow = latticeTriangleShadingType.getVerticesPerRow();
        PDRange[] colRange = new PDRange[numberOfColorComponents];
        for (int i = 0; i < numberOfColorComponents; ++i)
        {
            colRange[i] = latticeTriangleShadingType.getDecodeForParameter(2 + i);
        }
        List vlist = new ArrayList();
        long maxSrcCoord = (long) Math.pow(2, bitsPerCoordinate) - 1;
        long maxSrcColor = (long) Math.pow(2, bitsPerColorComponent) - 1;
        COSStream cosStream = (COSStream) cosDictionary;

        ImageInputStream mciis = new MemoryCacheImageInputStream(cosStream.createInputStream());
        try
        {
            while (true)
            {
                Vertex p;
                try
                {
                    p = readVertex(mciis, maxSrcCoord, maxSrcColor, rangeX, rangeY, colRange, matrix, xform);
                    vlist.add(p);
                }
                catch (EOFException ex)
                {
                    break;
                }
            }
        }
        finally
        {
            mciis.close();
        }
        int sz = vlist.size(), rowNum = sz / numPerRow;
        Vertex[][] latticeArray = new Vertex[rowNum][numPerRow];
        List list = new ArrayList();
        if (rowNum < 2)
        {
            // must have at least two rows; if not, return empty list
            return list;
        }
        for (int i = 0; i < rowNum; i++)
        {
            for (int j = 0; j < numPerRow; j++)
            {
                latticeArray[i][j] = vlist.get(i * numPerRow + j);
            }
        }

        for (int i = 0; i < rowNum - 1; i++)
        {
            for (int j = 0; j < numPerRow - 1; j++)
            {
                Point2D[] ps = new Point2D[] {
                    latticeArray[i][j].point,
                    latticeArray[i][j + 1].point,
                    latticeArray[i + 1][j].point  };

                float[][] cs = new float[][] {
                    latticeArray[i][j].color,
                    latticeArray[i][j + 1].color,
                    latticeArray[i + 1][j].color };

                list.add(new ShadedTriangle(ps, cs));

                ps = new Point2D[] {
                    latticeArray[i][j + 1].point,
                    latticeArray[i + 1][j].point,
                    latticeArray[i + 1][j + 1].point };

                cs = new float[][]{
                    latticeArray[i][j + 1].color,
                    latticeArray[i + 1][j].color,
                    latticeArray[i + 1][j + 1].color };

                list.add(new ShadedTriangle(ps, cs));
            }
        }
        return list;
    }

}