de.intarsys.pdf.pd.PDInterpolationFunction Maven / Gradle / Ivy

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/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * - Neither the name of intarsys nor the names of its contributors may be used
 *   to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.pdf.pd;

import de.intarsys.pdf.cos.COSArray;
import de.intarsys.pdf.cos.COSBasedObject;
import de.intarsys.pdf.cos.COSName;
import de.intarsys.pdf.cos.COSObject;

/**
 * Function implementation supporting interpolation.
 */
public class PDInterpolationFunction extends PDFunction {
	/**
	 * The meta class implementation
	 */
	static public class MetaClass extends PDFunction.MetaClass {
		protected MetaClass(Class paramInstanceClass) {
			super(paramInstanceClass);
		}

		@Override
		protected COSBasedObject doCreateCOSBasedObject(COSObject object) {
			return new PDInterpolationFunction(object);
		}
	}

	public static final COSName DK_C0 = COSName.constant("C0"); //$NON-NLS-1$

	public static final COSName DK_C1 = COSName.constant("C1"); //$NON-NLS-1$

	public static final COSName DK_N = COSName.constant("N"); //$NON-NLS-1$

	/** The meta class instance */
	public static final MetaClass META = new MetaClass(MetaClass.class
			.getDeclaringClass());

	private float[] c0;

	private float[] c1;

	private float n;

	protected PDInterpolationFunction(COSObject object) {
		super(object);

		COSArray cosC0;
		COSArray cosC1;

		cosC0 = cosGetDict().get(DK_C0).asArray();
		if (cosC0 == null) {
			c0 = new float[] { 0.0f };
		} else {
			c0 = new float[cosC0.size()];
			for (int i = 0; i < c0.length; i++) {
				c0[i] = cosC0.get(i).asNumber().floatValue();
			}
		}

		cosC1 = cosGetDict().get(DK_C1).asArray();
		if (cosC1 == null) {
			c1 = new float[] { 1.0f };
		} else {
			c1 = new float[cosC1.size()];
			for (int i = 0; i < c1.length; i++) {
				c1[i] = cosC1.get(i).asNumber().floatValue();
			}
		}

		// TODO 2 @ehk appropriate exception if null (required value according
		// to spec)
		n = cosGetDict().get(DK_N).asNumber().floatValue();
	}

	protected float[] evaluate(float value) {
		float[] result;

		if (value == 0.0) {
			return getC0();
		}
		if (value == 1.0) {
			return getC1();
		}

		// try to make faster by skipping accessor methods
		result = new float[getOutputSize()];
		for (int i = 0; i < result.length; i++) {
			result[i] = (float) (c0[i] + (Math.pow(value, n) * (c1[i] - c0[i])));
		}
		return result;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.pd.PDFunction#evaluate(float[])
	 */
	@Override
	public float[] evaluate(float[] values) {
		int outputSize;
		float[] result;

		outputSize = getOutputSize();
		result = new float[values.length * outputSize];

		for (int i = 0; i < values.length; i++) {
			System.arraycopy(evaluate(values[i]), i, result, i * outputSize,
					outputSize);
		}
		return result;
	}

	public float[] getC0() {
		return c0;
	}

	public float[] getC1() {
		return c1;
	}

	public float getN() {
		return n;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.pd.PDFunction#getOutputSize()
	 */
	@Override
	public int getOutputSize() {
		return getC0().length;
	}
}