/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
******************************************************************************/
package org.eclipse.swt.graphics;
// import org.eclipse.swt.internal.SerializableCompatibility;
import org.eclipse.swt.SWT;
import org.eclipse.swt.internal.SerializableCompatibility;
/**
* Instances of this class are descriptions of colors in terms of the primary
* additive color model (red, green and blue). A color may be described in terms
* of the relative intensities of these three primary colors. The brightness of
* each color is specified by a value in the range 0 to 255, where 0 indicates
* no color (blackness) and 255 indicates maximum intensity.
* <p>
* The hashCode() method in this class uses the values of the public fields to
* compute the hash value. When storing instances of the class in hashed
* collections, do not modify these fields after the object has been inserted.
* </p>
* <p>
* Application code does <em>not</em> need to explicitly release the resources
* managed by each instance when those instances are no longer required, and
* thus no <code>dispose()</code> method is provided.
* </p>
*
* @see Color
*
* @since 1.0
*/
public final class RGB implements SerializableCompatibility {
private static final long serialVersionUID = 1L;
/**
* the red component of the RGB
*/
public int red;
/**
* the green component of the RGB
*/
public int green;
/**
* the blue component of the RGB
*/
public int blue;
/**
* Constructs an instance of this class with the given red, green and blue
* values.
*
* @param red the red component of the new instance
* @param green the green component of the new instance
* @param blue the blue component of the new instance
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_INVALID_ARGUMENT - if the red, green or blue
* argument is not between 0 and 255</li>
* </ul>
*/
public RGB( int red, int green, int blue ) {
if( ( red > 255 )
|| ( red < 0 )
|| ( green > 255 )
|| ( green < 0 )
|| ( blue > 255 )
|| ( blue < 0 ) )
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
this.red = red;
this.green = green;
this.blue = blue;
}
/**
* Constructs an instance of this class with the given hue, saturation, and
* brightness.
*
* @param hue the hue value for the HSB color (from 0 to 360)
* @param saturation the saturation value for the HSB color (from 0 to 1)
* @param brightness the brightness value for the HSB color (from 0 to 1)
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_INVALID_ARGUMENT - if the hue is not between 0 and
* 360 or the saturation or brightness is not between 0 and 1</li>
* </ul>
* @since 1.0
*/
public RGB( float hue, float saturation, float brightness ) {
if( hue < 0
|| hue > 360
|| saturation < 0
|| saturation > 1
|| brightness < 0
|| brightness > 1 )
{
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
float r, g, b;
if( saturation == 0 ) {
r = g = b = brightness;
} else {
if( hue == 360 )
hue = 0;
hue /= 60;
int i = ( int )hue;
float f = hue - i;
float p = brightness * ( 1 - saturation );
float q = brightness * ( 1 - saturation * f );
float t = brightness * ( 1 - saturation * ( 1 - f ) );
switch( i ) {
case 0:
r = brightness;
g = t;
b = p;
break;
case 1:
r = q;
g = brightness;
b = p;
break;
case 2:
r = p;
g = brightness;
b = t;
break;
case 3:
r = p;
g = q;
b = brightness;
break;
case 4:
r = t;
g = p;
b = brightness;
break;
case 5:
default:
r = brightness;
g = p;
b = q;
break;
}
}
red = ( int )( r * 255 + 0.5 );
green = ( int )( g * 255 + 0.5 );
blue = ( int )( b * 255 + 0.5 );
}
/**
* Returns the hue, saturation, and brightness of the color.
*
* @return color space values in float format (hue, saturation, brightness)
* @since 1.0
*/
public float[] getHSB() {
float r = red / 255f;
float g = green / 255f;
float b = blue / 255f;
float max = Math.max( Math.max( r, g ), b );
float min = Math.min( Math.min( r, g ), b );
float delta = max - min;
float hue = 0;
float brightness = max;
float saturation = max == 0
? 0
: ( max - min ) / max;
if( delta != 0 ) {
if( r == max ) {
hue = ( g - b ) / delta;
} else {
if( g == max ) {
hue = 2 + ( b - r ) / delta;
} else {
hue = 4 + ( r - g ) / delta;
}
}
hue *= 60;
if( hue < 0 )
hue += 360;
}
return new float[]{
hue, saturation, brightness
};
}
/**
* Compares the argument to the receiver, and returns true if they represent
* the <em>same</em> object using a class specific comparison.
*
* @param object the object to compare with this object
* @return <code>true</code> if the object is the same as this object and
* <code>false</code> otherwise
* @see #hashCode()
*/
public boolean equals( Object object ) {
if( object == this )
return true;
if( !( object instanceof RGB ) )
return false;
RGB rgb = ( RGB )object;
return ( rgb.red == this.red )
&& ( rgb.green == this.green )
&& ( rgb.blue == this.blue );
}
/**
* Returns an integer hash code for the receiver. Any two objects that return
* <code>true</code> when passed to <code>equals</code> must return the
* same value for this method.
*
* @return the receiver's hash
* @see #equals(Object)
*/
public int hashCode() {
return ( blue << 16 ) | ( green << 8 ) | red;
}
/**
* Returns a string containing a concise, human-readable description of the
* receiver.
*
* @return a string representation of the <code>RGB</code>
*/
public String toString() {
return "RGB {" + red + ", " + green + ", " + blue + "}"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
}
}