/*
* $RCSfile: ConstantDescriptor.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:57:32 $
* $State: Exp $
*/
package javax.media.jai.operator;
import java.awt.RenderingHints;
import java.awt.image.RenderedImage;
import java.awt.image.renderable.ParameterBlock;
import java.awt.image.renderable.RenderableImage;
import javax.media.jai.JAI;
import javax.media.jai.OperationDescriptorImpl;
import javax.media.jai.ParameterBlockJAI;
import javax.media.jai.RenderableOp;
import javax.media.jai.RenderedOp;
import javax.media.jai.registry.RenderableRegistryMode;
import javax.media.jai.registry.RenderedRegistryMode;
import javax.media.jai.util.Range;
/**
* An <code>OperationDescriptor</code> describing the "Constant"
* operation.
*
* <p> The Constant operation creates a multi-banded, tiled rendered
* image, where all the pixels from the same band have a constant
* value. The width and height of the image must be specified and
* greater than 0. At least one constant must be supplied. The number
* of bands of the image is determined by the number of constant pixel
* values supplied in the "bandValues" parameter. The data type is
* determined by the type of the constants; this means all elements of
* the <code>bandValues</code> array must be of the same type.
*
* <p> If the <code>bandValues</code> array is a <code>Short</code>
* array, then <code>TYPE_USHORT</code> is used if all values are
* non-negative; otherwise <code>TYPE_SHORT</code> is used.
*
* <p><table border=1>
* <caption>Resource List</caption>
* <tr><th>Name</th> <th>Value</th></tr>
* <tr><td>GlobalName</td> <td>Constant</td></tr>
* <tr><td>LocalName</td> <td>Constant</td></tr>
* <tr><td>Vendor</td> <td>com.sun.media.jai</td></tr>
* <tr><td>Description</td> <td>Creates an image with
* constant pixel values.</td></tr>
* <tr><td>DocURL</td> <td>http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/ConstantDescriptor.html</td></tr>
* <tr><td>Version</td> <td>1.0</td></tr>
* <tr><td>arg0Desc</td> <td>Image width in pixels.</td></tr>
* <tr><td>arg1Desc</td> <td>Image height in pixels.</td></tr>
* <tr><td>arg2Desc</td> <td>The constant pixel band values.</td></tr>
* </table></p>
*
* <p><table border=1>
* <caption>Parameter List</caption>
* <tr><th>Name</th> <th>Class Type</th>
* <th>Default Value</th></tr>
* <tr><td>width</td> <td>java.lang.Float</td>
* <td>NO_PARAMETER_DEFAULT</td>
* <tr><td>height</td> <td>java.lang.Float</td>
* <td>NO_PARAMETER_DEFAULT</td>
* <tr><td>bandValues</td> <td>java.lang.Number[]</td>
* <td>NO_PARAMETER_DEFAULT</td>
* </table></p>
*
* @see javax.media.jai.OperationDescriptor
*/
public class ConstantDescriptor extends OperationDescriptorImpl {
/**
* The resource strings that provide the general documentation
* and specify the parameter list for this operation.
*/
private static final String[][] resources = {
{"GlobalName", "Constant"},
{"LocalName", "Constant"},
{"Vendor", "com.sun.media.jai"},
{"Description", JaiI18N.getString("ConstantDescriptor0")},
{"DocURL", "http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/ConstantDescriptor.html"},
{"Version", JaiI18N.getString("DescriptorVersion")},
{"arg0Desc", JaiI18N.getString("ConstantDescriptor1")},
{"arg1Desc", JaiI18N.getString("ConstantDescriptor2")},
{"arg2Desc", JaiI18N.getString("ConstantDescriptor3")}
};
/** The parameter class list for this operation. */
private static final Class[] paramClasses = {
java.lang.Float.class,
java.lang.Float.class,
java.lang.Number[].class
};
/** The parameter name list for this operation. */
private static final String[] paramNames = {
"width", "height", "bandValues"
};
/** The parameter default value list for this operation. */
private static final Object[] paramDefaults = {
NO_PARAMETER_DEFAULT, NO_PARAMETER_DEFAULT, NO_PARAMETER_DEFAULT
};
private static final String[] supportedModes = {
"rendered",
"renderable"
};
private static final Object[] validParamValues = {
new Range(Float.class, new Float(0.0F), false, null, false),
new Range(Float.class, new Float(0.0F), false, null, false),
null
};
/** Constructor. */
public ConstantDescriptor() {
super(resources, supportedModes, 0,
paramNames, paramClasses, paramDefaults, validParamValues);
}
/**
* Validates the input parameters.
*
* <p> In addition to the standard checks performed by the
* superclass method, this method checks that "width" and "height"
* are greater than 0 (for rendered mode) and that "bandValues" has
* length at least 1.
*/
protected boolean validateParameters(String modeName,
ParameterBlock args,
StringBuffer message) {
if (!super.validateParameters(modeName, args, message)) {
return false;
}
int length = ((Number[])args.getObjectParameter(2)).length;
if (length < 1) {
message.append(getName() + " " +
JaiI18N.getString("ConstantDescriptor4"));
return false;
}
if (modeName.equalsIgnoreCase("rendered")) {
int width = Math.round(args.getFloatParameter(0));
int height = Math.round(args.getFloatParameter(1));
if ((width < 1) || (height < 1)) {
message.append(getName() + " " +
JaiI18N.getString("ConstantDescriptor5"));
return false;
}
} else if (modeName.equalsIgnoreCase("renderable")) {
float width = args.getFloatParameter(0);
float height = args.getFloatParameter(1);
if ((width <= 0.0F) || (height <= 0.0F)) {
message.append(getName() + " " +
JaiI18N.getString("ConstantDescriptor6"));
return false;
}
}
return true;
}
/**
* Creates an image with constant pixel values.
*
* <p>Creates a <code>ParameterBlockJAI</code> from all
* supplied arguments except <code>hints</code> and invokes
* {@link JAI#create(String,ParameterBlock,RenderingHints)}.
*
* @see JAI
* @see ParameterBlockJAI
* @see RenderedOp
*
* @param width Image width in pixels.
* @param height Image height in pixels.
* @param bandValues The constant pixel band values.
* @param hints The <code>RenderingHints</code> to use.
* May be <code>null</code>.
* @return The <code>RenderedOp</code> destination.
* @throws IllegalArgumentException if <code>width</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>height</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>bandValues</code> is <code>null</code>.
*/
public static RenderedOp create(Float width,
Float height,
Number[] bandValues,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("Constant",
RenderedRegistryMode.MODE_NAME);
pb.setParameter("width", width);
pb.setParameter("height", height);
pb.setParameter("bandValues", bandValues);
return JAI.create("Constant", pb, hints);
}
/**
* Creates an image with constant pixel values.
*
* <p>Creates a <code>ParameterBlockJAI</code> from all
* supplied arguments except <code>hints</code> and invokes
* {@link JAI#createRenderable(String,ParameterBlock,RenderingHints)}.
*
* @see JAI
* @see ParameterBlockJAI
* @see RenderableOp
*
* @param width Image width in pixels.
* @param height Image height in pixels.
* @param bandValues The constant pixel band values.
* @param hints The <code>RenderingHints</code> to use.
* May be <code>null</code>.
* @return The <code>RenderableOp</code> destination.
* @throws IllegalArgumentException if <code>width</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>height</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>bandValues</code> is <code>null</code>.
*/
public static RenderableOp createRenderable(Float width,
Float height,
Number[] bandValues,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("Constant",
RenderableRegistryMode.MODE_NAME);
pb.setParameter("width", width);
pb.setParameter("height", height);
pb.setParameter("bandValues", bandValues);
return JAI.createRenderable("Constant", pb, hints);
}
}