org.apache.pdfbox.pdmodel.graphics.shading.ShadingContext 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.
/*
* Copyright 2014 The Apache Software Foundation.
*
* Licensed 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.PaintContext;
import java.awt.Transparency;
import java.awt.color.ColorSpace;
import java.awt.geom.AffineTransform;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.io.IOException;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.pdmodel.graphics.color.PDColorSpace;
import org.apache.pdfbox.util.Matrix;
/**
* A base class to handle what is common to all shading types.
*
* @author Shaola Ren
* @author Tilman Hausherr
*/
public abstract class ShadingContext implements PaintContext
{
private float[] background;
private int rgbBackground;
private final PDShading shading;
private ColorModel outputColorModel;
private PDColorSpace shadingColorSpace;
/**
* Constructor.
*
* @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 java.io.IOException if there is an error getting the color space
* or doing background color conversion.
*/
public ShadingContext(PDShading shading, ColorModel cm, AffineTransform xform,
Matrix matrix) throws IOException
{
this.shading = shading;
shadingColorSpace = shading.getColorSpace();
// create the output color model using RGB+alpha as color space
ColorSpace outputCS = ColorSpace.getInstance(ColorSpace.CS_sRGB);
outputColorModel = new ComponentColorModel(outputCS, true, false, Transparency.TRANSLUCENT,
DataBuffer.TYPE_BYTE);
// get background values if available
COSArray bg = shading.getBackground();
if (bg != null)
{
background = bg.toFloatArray();
rgbBackground = convertToRGB(background);
}
}
PDColorSpace getShadingColorSpace()
{
return shadingColorSpace;
}
PDShading getShading()
{
return shading;
}
float[] getBackground()
{
return background;
}
int getRgbBackground()
{
return rgbBackground;
}
/**
* Convert color values from shading colorspace to RGB color values encoded
* into an integer.
*
* @param values color values in shading colorspace.
* @return RGB values encoded in an integer.
* @throws java.io.IOException if the color conversion fails.
*/
final int convertToRGB(float[] values) throws IOException
{
int normRGBValues;
float[] rgbValues = shadingColorSpace.toRGB(values);
normRGBValues = (int) (rgbValues[0] * 255);
normRGBValues |= (int) (rgbValues[1] * 255) << 8;
normRGBValues |= (int) (rgbValues[2] * 255) << 16;
return normRGBValues;
}
@Override
public ColorModel getColorModel()
{
return outputColorModel;
}
@Override
public void dispose()
{
outputColorModel = null;
shadingColorSpace = null;
}
}