/*
* 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.geom.NoninvertibleTransformException;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.pdmodel.common.function.PDFunction;
import org.apache.pdfbox.pdmodel.graphics.color.PDColorSpace;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceN;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceRGB;
import org.apache.pdfbox.pdmodel.graphics.color.PDSeparation;
import org.apache.pdfbox.util.Matrix;
/**
* This represents the Paint of a type 1 (Function based) shading context.
*
* @author lehmi
* @author Tilman Hausherr <tilman@snafu.de>
*/
class Type1ShadingContext implements PaintContext
{
private static final Log LOG = LogFactory.getLog(Type1ShadingContext.class);
private ColorModel outputColorModel;
private ColorSpace shadingColorSpace;
private PDFunction shadingTinttransform;
private PDShadingType1 shadingType;
private AffineTransform rat;
private float[] domain;
private Matrix matrix;
private float[] background;
/**
* Constructor creates an instance to be used for fill operations.
*
* @param shadingType1 the shading type to be used
* @param colorModelValue the color model to be used
* @param xform transformation for user to device space
* @param ctm current transformation matrix
* @param pageHeight height of the current page
*
*/
public Type1ShadingContext(PDShadingType1 shadingType1, ColorModel colorModelValue,
AffineTransform xform, Matrix currentTransformationMatrix, int pageHeight)
{
shadingType = shadingType1;
// PDFBOX-1966 flip the AffineTransform in 1.8 branch
//TODO find out why AffineTransform passed in 1.8 branch is flipped
xform.scale(1,-1);
xform.translate(0, -pageHeight);
// colorSpace
try
{
PDColorSpace cs = shadingType.getColorSpace();
if (!(cs instanceof PDDeviceRGB))
{
// we have to create an instance of the shading colorspace if it isn't RGB
shadingColorSpace = cs.getJavaColorSpace();
if (cs instanceof PDDeviceN)
{
shadingTinttransform = ((PDDeviceN) cs).getTintTransform();
}
else if (cs instanceof PDSeparation)
{
shadingTinttransform = ((PDSeparation) cs).getTintTransform();
}
}
}
catch (IOException exception)
{
LOG.error("error while creating colorSpace", exception);
}
// create the output colormodel using RGB+alpha as colorspace
ColorSpace outputCS = ColorSpace.getInstance(ColorSpace.CS_sRGB);
outputColorModel = new ComponentColorModel(outputCS, true, false, Transparency.TRANSLUCENT,
DataBuffer.TYPE_BYTE);
// spec p.308
// (Optional) An array of four numbers [ xmin xmax ymin ymax ]
// specifying the rectangular domain of coordinates over which the
// color function(s) are defined. Default value: [ 0.0 1.0 0.0 1.0 ].
if (shadingType.getDomain() != null)
{
domain = shadingType.getDomain().toFloatArray();
}
else
{
domain = new float[]
{
0, 1, 0, 1
};
}
matrix = shadingType.getMatrix();
if (matrix == null)
{
matrix = new Matrix();
}
try
{
// get inverse transform to be independent of
// shading matrix and current user / device space
// when handling actual pixels in getRaster()
rat = matrix.createAffineTransform().createInverse();
rat.concatenate(currentTransformationMatrix.createAffineTransform().createInverse());
rat.concatenate(xform.createInverse());
}
catch (NoninvertibleTransformException ex)
{
LOG.error(ex,ex);
}
// get background values if available
COSArray bg = shadingType1.getBackground();
if (bg != null)
{
background = bg.toFloatArray();
}
}
/**
* {@inheritDoc}
*/
public void dispose()
{
outputColorModel = null;
shadingColorSpace = null;
shadingTinttransform = null;
shadingType = null;
}
/**
* {@inheritDoc}
*/
public ColorModel getColorModel()
{
return outputColorModel;
}
/**
* {@inheritDoc}
*/
public Raster getRaster(int x, int y, int w, int h)
{
// create writable raster
WritableRaster raster = getColorModel().createCompatibleWritableRaster(w, h);
int[] data = new int[w * h * 4];
for (int j = 0; j < h; j++)
{
for (int i = 0; i < w; i++)
{
int index = (j * w + i) * 4;
boolean useBackground = false;
float[] values = new float[]
{
x + i, y + j
};
rat.transform(values, 0, values, 0, 1);
if (values[0] < domain[0] || values[0] > domain[1] || values[1] < domain[2] || values[1] > domain[3])
{
if (background != null)
{
useBackground = true;
}
else
{
continue;
}
}
try
{
if (useBackground)
{
values = background;
}
else
{
values = shadingType.evalFunction(values);
}
// convert color values from shading colorspace to RGB
if (shadingColorSpace != null)
{
if (shadingTinttransform != null)
{
values = shadingTinttransform.eval(values);
}
values = shadingColorSpace.toRGB(values);
}
}
catch (IOException exception)
{
LOG.error("error while processing a function", exception);
}
data[index] = (int) (values[0] * 255);
data[index + 1] = (int) (values[1] * 255);
data[index + 2] = (int) (values[2] * 255);
data[index + 3] = 255;
}
}
raster.setPixels(0, 0, w, h, data);
return raster;
}
public float[] getDomain()
{
return domain;
}
public PDFunction getShadingTintTransform()
{
return shadingTinttransform;
}
}