Mega Code Archive
Common color utilities
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/*
* This code is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This code is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
//package no.geosoft.cc.color.ui;
import java.awt.Color;
/**
* Common color utilities.
*
* @author <a href="mailto:jacob.dreyer@geosoft.no">Jacob Dreyer</a>
*/
public class ColorUtil
{
/**
* Blend two colors.
*
* @param color1 First color to blend.
* @param color2 Second color to blend.
* @param ratio Blend ratio. 0.5 will give even blend, 1.0 will return
* color1, 0.0 will return color2 and so on.
* @return Blended color.
*/
public static Color blend (Color color1, Color color2, double ratio)
{
float r = (float) ratio;
float ir = (float) 1.0 - r;
float rgb1[] = new float[3];
float rgb2[] = new float[3];
color1.getColorComponents (rgb1);
color2.getColorComponents (rgb2);
Color color = new Color (rgb1[0] * r + rgb2[0] * ir,
rgb1[1] * r + rgb2[1] * ir,
rgb1[2] * r + rgb2[2] * ir);
return color;
}
/**
* Make an even blend between two colors.
*
* @param c1 First color to blend.
* @param c2 Second color to blend.
* @return Blended color.
*/
public static Color blend (Color color1, Color color2)
{
return ColorUtil.blend (color1, color2, 0.5);
}
/**
* Make a color darker.
*
* @param color Color to make darker.
* @param fraction Darkness fraction.
* @return Darker color.
*/
public static Color darker (Color color, double fraction)
{
int red = (int) Math.round (color.getRed() * (1.0 - fraction));
int green = (int) Math.round (color.getGreen() * (1.0 - fraction));
int blue = (int) Math.round (color.getBlue() * (1.0 - fraction));
if (red < 0) red = 0; else if (red > 255) red = 255;
if (green < 0) green = 0; else if (green > 255) green = 255;
if (blue < 0) blue = 0; else if (blue > 255) blue = 255;
int alpha = color.getAlpha();
return new Color (red, green, blue, alpha);
}
/**
* Make a color lighter.
*
* @param color Color to make lighter.
* @param fraction Darkness fraction.
* @return Lighter color.
*/
public static Color lighter (Color color, double fraction)
{
int red = (int) Math.round (color.getRed() * (1.0 + fraction));
int green = (int) Math.round (color.getGreen() * (1.0 + fraction));
int blue = (int) Math.round (color.getBlue() * (1.0 + fraction));
if (red < 0) red = 0; else if (red > 255) red = 255;
if (green < 0) green = 0; else if (green > 255) green = 255;
if (blue < 0) blue = 0; else if (blue > 255) blue = 255;
int alpha = color.getAlpha();
return new Color (red, green, blue, alpha);
}
/**
* Return the hex name of a specified color.
*
* @param color Color to get hex name of.
* @return Hex name of color: "rrggbb".
*/
public static String getHexName (Color color)
{
int r = color.getRed();
int g = color.getGreen();
int b = color.getBlue();
String rHex = Integer.toString (r, 16);
String gHex = Integer.toString (g, 16);
String bHex = Integer.toString (b, 16);
return (rHex.length() == 2 ? "" + rHex : "0" + rHex) +
(gHex.length() == 2 ? "" + gHex : "0" + gHex) +
(bHex.length() == 2 ? "" + bHex : "0" + bHex);
}
/**
* Return the "distance" between two colors. The rgb entries are taken
* to be coordinates in a 3D space [0.0-1.0], and this method returnes
* the distance between the coordinates for the first and second color.
*
* @param r1, g1, b1 First color.
* @param r2, g2, b2 Second color.
* @return Distance bwetween colors.
*/
public static double colorDistance (double r1, double g1, double b1,
double r2, double g2, double b2)
{
double a = r2 - r1;
double b = g2 - g1;
double c = b2 - b1;
return Math.sqrt (a*a + b*b + c*c);
}
/**
* Return the "distance" between two colors.
*
* @param color1 First color [r,g,b].
* @param color2 Second color [r,g,b].
* @return Distance bwetween colors.
*/
public static double colorDistance (double[] color1, double[] color2)
{
return ColorUtil.colorDistance (color1[0], color1[1], color1[2],
color2[0], color2[1], color2[2]);
}
/**
* Return the "distance" between two colors.
*
* @param color1 First color.
* @param color2 Second color.
* @return Distance between colors.
*/
public static double colorDistance (Color color1, Color color2)
{
float rgb1[] = new float[3];
float rgb2[] = new float[3];
color1.getColorComponents (rgb1);
color2.getColorComponents (rgb2);
return ColorUtil.colorDistance (rgb1[0], rgb1[1], rgb1[2],
rgb2[0], rgb2[1], rgb2[2]);
}
/**
* Check if a color is more dark than light. Useful if an entity of
* this color is to be labeled: Use white label on a "dark" color and
* black label on a "light" color.
*
* @param r,g,b Color to check.
* @return True if this is a "dark" color, false otherwise.
*/
public static boolean isDark (double r, double g, double b)
{
// Measure distance to white and black respectively
double dWhite = ColorUtil.colorDistance (r, g, b, 1.0, 1.0, 1.0);
double dBlack = ColorUtil.colorDistance (r, g, b, 0.0, 0.0, 0.0);
return dBlack < dWhite;
}
/**
* Check if a color is more dark than light. Useful if an entity of
* this color is to be labeled: Use white label on a "dark" color and
* black label on a "light" color.
*
* @param color Color to check.
* @return True if this is a "dark" color, false otherwise.
*/
public static boolean isDark (Color color)
{
float r = color.getRed() / 255.0f;
float g = color.getGreen() / 255.0f;
float b = color.getBlue() / 255.0f;
return isDark (r, g, b);
}
}
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