pdfbox/src/main/java/org/apache/pdfbox/pdmodel/graphics/shading/AxialShadingContext.java - pdfbox - Git at Google

 /*
  * 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.NoninvertibleTransformException;
 import java.awt.image.ColorModel;
 import java.awt.image.Raster;
 import java.awt.image.WritableRaster;
 import java.io.IOException;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
 import org.apache.pdfbox.cos.COSArray;
 import org.apache.pdfbox.cos.COSBoolean;
 import org.apache.pdfbox.pdmodel.common.function.PDFunction;
 import org.apache.pdfbox.util.Matrix;

 /**
  * AWT PaintContext for axial shading.
  *
  * Performance improvement done as part of GSoC2014, Tilman Hausherr is the mentor.
  *
  * @author Shaola Ren
  */
 public class AxialShadingContext extends ShadingContext
 {
     private static final Logger LOG = LogManager.getLogger(AxialShadingContext.class);

     private PDShadingType2 axialShadingType;

     private final float[] coords;
     private final float[] domain;
     private final boolean[] extend;
     private final double x1x0;
     private final double y1y0;
     private final float d1d0;
     private final double denom;

     private final int factor;
     private final int[] colorTable;

     private AffineTransform rat;

     /**
      * Constructor creates an instance to be used for fill operations.
      *
      * @param shading the shading type to be used
      * @param colorModel 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
      * @param deviceBounds the bounds of the area to paint, in device units
      * @throws IOException if there is an error getting the color space or doing color conversion.
      */
     public AxialShadingContext(PDShadingType2 shading, ColorModel colorModel, AffineTransform xform,
                                Matrix matrix, Rectangle deviceBounds) throws IOException
     {
         super(shading, colorModel, xform, matrix);
         this.axialShadingType = shading;
         coords = shading.getCoords().toFloatArray();

         // domain values
         if (shading.getDomain() != null)
         {
             domain = shading.getDomain().toFloatArray();
         }
         else
         {
             // set default values
             domain = new float[] { 0, 1 };
         }
         // extend values
         COSArray extendValues = shading.getExtend();
         if (extendValues != null)
         {
             extend = new boolean[2];
             extend[0] = ((COSBoolean) extendValues.getObject(0)).getValue();
             extend[1] = ((COSBoolean) extendValues.getObject(1)).getValue();
         }
         else
         {
             // set default values
             extend = new boolean[] { false, false };
         }
         // calculate some constants to be used in getRaster
         x1x0 = coords[2] - coords[0];
         y1y0 = coords[3] - coords[1];
         d1d0 = domain[1] - domain[0];
         denom = Math.pow(x1x0, 2) + Math.pow(y1y0, 2);

         try
         {
             // get inverse transform to be independent of current user / device space
             // when handling actual pixels in getRaster()
             rat = matrix.createAffineTransform().createInverse();
             rat.concatenate(xform.createInverse());
         }
         catch (NoninvertibleTransformException ex)
         {
             LOG.error("{}, matrix: {}", ex.getMessage(), matrix, ex);
             rat = new AffineTransform();
         }

         // shading space -> device space
         AffineTransform shadingToDevice = (AffineTransform)xform.clone();
         shadingToDevice.concatenate(matrix.createAffineTransform());

         // worst case for the number of steps is opposite diagonal corners, so use that
         double dist = Math.sqrt(Math.pow(deviceBounds.getMaxX() - deviceBounds.getMinX(), 2) +
                                 Math.pow(deviceBounds.getMaxY() - deviceBounds.getMinY(), 2));
         factor = (int) Math.ceil(dist);

         // build the color table for the given number of steps
         colorTable = calcColorTable();
     }

     /**
      * Calculate the color on the axial line and store them in an array.
      *
      * @return an array, index denotes the relative position, the corresponding
      * value is the color on the axial line
      * @throws IOException if the color conversion fails.
      */
     private int[] calcColorTable() throws IOException
     {
         int[] map = new int[factor + 1];
         if (factor == 0 || Float.compare(d1d0, 0) == 0)
         {
             float[] values = axialShadingType.evalFunction(domain[0]);
             map[0] = convertToRGB(values);
         }
         else
         {
             for (int i = 0; i <= factor; i++)
             {
                 float t = domain[0] + d1d0 * i / factor;
                 float[] values = axialShadingType.evalFunction(t);
                 map[i] = convertToRGB(values);
             }
         }
         return map;
     }

     @Override
     public void dispose()
     {
         super.dispose();
         axialShadingType = null;
     }

     @Override
     public Raster getRaster(int x, int y, int w, int h)
     {
         // create writable raster
         WritableRaster raster = getColorModel().createCompatibleWritableRaster(w, h);
         boolean useBackground;
         int[] data = new int[w * h * 4];
         float[] values = new float[2];
         for (int j = 0; j < h; j++)
         {
             for (int i = 0; i < w; i++)
             {
                 useBackground = false;
                 values[0] = x + i;
                 values[1] = y + j;
                 rat.transform(values, 0, values, 0, 1);
                 double inputValue = x1x0 * (values[0] - coords[0]) + y1y0 * (values[1] - coords[1]);
                 // TODO this happens if start == end, see PDFBOX-1442
                 if (Double.compare(denom, 0) == 0)
                 {
                     if (getBackground() == null)
                     {
                         continue;
                     }
                     useBackground = true;
                 }
                 else
                 {
                     inputValue /= denom;
                 }
                 // input value is out of range
                 if (inputValue < 0)
                 {
                     // the shading has to be extended if extend[0] == true
                     if (extend[0])
                     {
                         inputValue = domain[0];
                     }
                     else
                     {
                         if (getBackground() == null)
                         {
                             continue;
                         }
                         useBackground = true;
                     }
                 }
                 // input value is out of range
                 else if (inputValue > 1)
                 {
                     // the shading has to be extended if extend[1] == true
                     if (extend[1])
                     {
                         inputValue = domain[1];
                     }
                     else
                     {
                         if (getBackground() == null)
                         {
                             continue;
                         }
                         useBackground = true;
                     }
                 }
                 int value;
                 if (useBackground)
                 {
                     // use the given background color values
                     value = getRgbBackground();
                 }
                 else
                 {
                     int key = (int) (inputValue * factor);
                     value = colorTable[key];
                 }
                 int index = (j * w + i) * 4;
                 data[index] = value & 255;
                 value >>= 8;
                 data[index + 1] = value & 255;
                 value >>= 8;
                 data[index + 2] = value & 255;
                 data[index + 3] = 255;
             }
         }
         raster.setPixels(0, 0, w, h, data);
         return raster;
     }

     /**
      * Returns the coords values.
      *
      * @return the coords values
      */
     public float[] getCoords()
     {
         return coords;
     }

     /**
      * Returns the domain values.
      *
      * @return the domain values
      */
     public float[] getDomain()
     {
         return domain;
     }

     /**
      * Returns the extend values.
      *
      * @return the extend values
      */
     public boolean[] getExtend()
     {
         return extend;
     }

     /**
      * Returns the function.
      *
      * @return the function
      * @throws java.io.IOException if we were not able to create the function.
      */
     public PDFunction getFunction() throws IOException
     {
         return axialShadingType.getFunction();
     }
 }
	/*
	* 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.NoninvertibleTransformException;
	import java.awt.image.ColorModel;
	import java.awt.image.Raster;
	import java.awt.image.WritableRaster;
	import java.io.IOException;
	import org.apache.logging.log4j.Logger;
	import org.apache.logging.log4j.LogManager;
	import org.apache.pdfbox.cos.COSArray;
	import org.apache.pdfbox.cos.COSBoolean;
	import org.apache.pdfbox.pdmodel.common.function.PDFunction;
	import org.apache.pdfbox.util.Matrix;

	/**
	* AWT PaintContext for axial shading.
	*
	* Performance improvement done as part of GSoC2014, Tilman Hausherr is the mentor.
	*
	* @author Shaola Ren
	*/
	public class AxialShadingContext extends ShadingContext
	{
	private static final Logger LOG = LogManager.getLogger(AxialShadingContext.class);

	private PDShadingType2 axialShadingType;

	private final float[] coords;
	private final float[] domain;
	private final boolean[] extend;
	private final double x1x0;
	private final double y1y0;
	private final float d1d0;
	private final double denom;

	private final int factor;
	private final int[] colorTable;

	private AffineTransform rat;

	/**
	* Constructor creates an instance to be used for fill operations.
	*
	* @param shading the shading type to be used
	* @param colorModel 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
	* @param deviceBounds the bounds of the area to paint, in device units
	* @throws IOException if there is an error getting the color space or doing color conversion.
	*/
	public AxialShadingContext(PDShadingType2 shading, ColorModel colorModel, AffineTransform xform,
	Matrix matrix, Rectangle deviceBounds) throws IOException
	{
	super(shading, colorModel, xform, matrix);
	this.axialShadingType = shading;
	coords = shading.getCoords().toFloatArray();

	// domain values
	if (shading.getDomain() != null)
	{
	domain = shading.getDomain().toFloatArray();
	}
	else
	{
	// set default values
	domain = new float[] { 0, 1 };
	}
	// extend values
	COSArray extendValues = shading.getExtend();
	if (extendValues != null)
	{
	extend = new boolean[2];
	extend[0] = ((COSBoolean) extendValues.getObject(0)).getValue();
	extend[1] = ((COSBoolean) extendValues.getObject(1)).getValue();
	}
	else
	{
	// set default values
	extend = new boolean[] { false, false };
	}
	// calculate some constants to be used in getRaster
	x1x0 = coords[2] - coords[0];
	y1y0 = coords[3] - coords[1];
	d1d0 = domain[1] - domain[0];
	denom = Math.pow(x1x0, 2) + Math.pow(y1y0, 2);

	try
	{
	// get inverse transform to be independent of current user / device space
	// when handling actual pixels in getRaster()
	rat = matrix.createAffineTransform().createInverse();
	rat.concatenate(xform.createInverse());
	}
	catch (NoninvertibleTransformException ex)
	{
	LOG.error("{}, matrix: {}", ex.getMessage(), matrix, ex);
	rat = new AffineTransform();
	}

	// shading space -> device space
	AffineTransform shadingToDevice = (AffineTransform)xform.clone();
	shadingToDevice.concatenate(matrix.createAffineTransform());

	// worst case for the number of steps is opposite diagonal corners, so use that
	double dist = Math.sqrt(Math.pow(deviceBounds.getMaxX() - deviceBounds.getMinX(), 2) +
	Math.pow(deviceBounds.getMaxY() - deviceBounds.getMinY(), 2));
	factor = (int) Math.ceil(dist);

	// build the color table for the given number of steps
	colorTable = calcColorTable();
	}

	/**
	* Calculate the color on the axial line and store them in an array.
	*
	* @return an array, index denotes the relative position, the corresponding
	* value is the color on the axial line
	* @throws IOException if the color conversion fails.
	*/
	private int[] calcColorTable() throws IOException
	{
	int[] map = new int[factor + 1];
	if (factor == 0 \|\| Float.compare(d1d0, 0) == 0)
	{
	float[] values = axialShadingType.evalFunction(domain[0]);
	map[0] = convertToRGB(values);
	}
	else
	{
	for (int i = 0; i <= factor; i++)
	{
	float t = domain[0] + d1d0 * i / factor;
	float[] values = axialShadingType.evalFunction(t);
	map[i] = convertToRGB(values);
	}
	}
	return map;
	}

	@Override
	public void dispose()
	{
	super.dispose();
	axialShadingType = null;
	}

	@Override
	public Raster getRaster(int x, int y, int w, int h)
	{
	// create writable raster
	WritableRaster raster = getColorModel().createCompatibleWritableRaster(w, h);
	boolean useBackground;
	int[] data = new int[w * h * 4];
	float[] values = new float[2];
	for (int j = 0; j < h; j++)
	{
	for (int i = 0; i < w; i++)
	{
	useBackground = false;
	values[0] = x + i;
	values[1] = y + j;
	rat.transform(values, 0, values, 0, 1);
	double inputValue = x1x0 * (values[0] - coords[0]) + y1y0 * (values[1] - coords[1]);
	// TODO this happens if start == end, see PDFBOX-1442
	if (Double.compare(denom, 0) == 0)
	{
	if (getBackground() == null)
	{
	continue;
	}
	useBackground = true;
	}
	else
	{
	inputValue /= denom;
	}
	// input value is out of range
	if (inputValue < 0)
	{
	// the shading has to be extended if extend[0] == true
	if (extend[0])
	{
	inputValue = domain[0];
	}
	else
	{
	if (getBackground() == null)
	{
	continue;
	}
	useBackground = true;
	}
	}
	// input value is out of range
	else if (inputValue > 1)
	{
	// the shading has to be extended if extend[1] == true
	if (extend[1])
	{
	inputValue = domain[1];
	}
	else
	{
	if (getBackground() == null)
	{
	continue;
	}
	useBackground = true;
	}
	}
	int value;
	if (useBackground)
	{
	// use the given background color values
	value = getRgbBackground();
	}
	else
	{
	int key = (int) (inputValue * factor);
	value = colorTable[key];
	}
	int index = (j * w + i) * 4;
	data[index] = value & 255;
	value >>= 8;
	data[index + 1] = value & 255;
	value >>= 8;
	data[index + 2] = value & 255;
	data[index + 3] = 255;
	}
	}
	raster.setPixels(0, 0, w, h, data);
	return raster;
	}

	/**
	* Returns the coords values.
	*
	* @return the coords values
	*/
	public float[] getCoords()
	{
	return coords;
	}

	/**
	* Returns the domain values.
	*
	* @return the domain values
	*/
	public float[] getDomain()
	{
	return domain;
	}

	/**
	* Returns the extend values.
	*
	* @return the extend values
	*/
	public boolean[] getExtend()
	{
	return extend;
	}

	/**
	* Returns the function.
	*
	* @return the function
	* @throws java.io.IOException if we were not able to create the function.
	*/
	public PDFunction getFunction() throws IOException
	{
	return axialShadingType.getFunction();
	}
	}