Graphic: Inner glow

[happy_hippie]

Hey.

I have just finished some code, that will allow you to create an inner glow inside an Area.
I would be happy if you would try it and tell me what you think.

I also provides a test, that draws an ellipse and a star, with inner glows.
It uses JH Labs image API to create the glow effect, which can be gotten here: http://www.jhlabs.com/ip/filters/index.html

This is the "Inner glow" source code:

import com.jhlabs.image.GaussianFilter;
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.image.BufferedImage;

/**
*
* @author Dan From <dan.from@gmail.com>
*/
public class Glow
{

private BufferedImage glow = null;
private Color color = null;
private int size = 0;

public Glow (Color c, int s)
{
color = c;
size = s;
}

public void paint (Graphics2D g, Area a) {
int width = a.getBounds().width + 2;
int height = a.getBounds().height + 2;

glow = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = glow.createGraphics();

Area area1 = new Area(new Rectangle(0, 0, width, height));
a.transform(AffineTransform.getTranslateInstance(1, 1));
area1.subtract(a);

BufferedImage tmp = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g3 = tmp.createGraphics();
g3.setPaint(new GradientPaint(0, 0, color, width, height, color));
g3.fill(area1);

GaussianFilter gf = new GaussianFilter(size+1);
glow = gf.filter(tmp, glow);

AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC_IN, (float)0.0);
g2.setColor(Color.blue);
g2.setComposite(ac);
g2.fill(area1);

g.drawImage(glow, null, -1, -1);
g.drawImage(glow, null, -1, -1);
}

}

This is the code for the test:

import java.awt.Dimension;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.geom.Ellipse2D;
import java.awt.geom.GeneralPath;
import javax.swing.JPanel;
import org.frog.effects.Glow;

public class GlowDemo extends JFrame
{

public GlowDemo ()
{
super("Inner glow demo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

PaintCanvas pc = new PaintCanvas();
pc.setPreferredSize(new Dimension(500, 500));

getContentPane().add(pc);
pack();
setLocationRelativeTo(null);
setVisible(true);
}

public static void main (String args[])
{
new GlowDemo();
}

}

/**
*
* @author Skruppe
*/
class PaintCanvas extends JPanel
{

public PaintCanvas ()
{
super();
}

@Override
public void paintComponent (Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
AffineTransform atBef = g2.getTransform();

// Circle start
g2.translate(10, 10);
Area a = new Area(new Ellipse2D.Double(0, 0, 150, 150));

// Background
g2.setBackground(new Color(28, 28, 28));
g2.fill(a);

// Circle
g2.setColor(new Color(3, 56, 89));
g2.fillOval(0, 0, 150, 150);

Glow glow = new Glow(Color.black, 40, 150);
glow.paint(g2, a);

g2.setTransform(atBef);
// Circle end

// Star start
g2.translate(170, 10);

GeneralPath gp = new GeneralPath();
gp.moveTo(0, 51);
gp.lineTo(53, 51);
gp.lineTo(72, 0);
gp.lineTo(89, 51);
gp.lineTo(143, 51);
gp.lineTo(100, 84);
gp.lineTo(116, 135);
gp.lineTo(72, 105);
gp.lineTo(28, 135);
gp.lineTo(43, 84);
gp.lineTo(0, 51);

Area star = new Area(gp);

// Background
g2.setColor(new Color(86, 3, 89));
g2.fill(star);

// Star

Glow glow1 = new Glow(Color.red, 10, 150);
glow1.paint(g2, new Area(gp));

g2.setTransform(atBef);
// Circle end
}

}

[dlorde]

I would be happy if you would try it and tell me what you think.

I think it won't compile because it calls a Glow constructor with 3 arguments, that doesn't exist in the code you posted.

God is in the details...
M. van der Rohe

[happy_hippie]

Whoops, that's correct.
It was from when i tested
Here is the correct test code, without the last parameter

import java.awt.Dimension;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.geom.Ellipse2D;
import java.awt.geom.GeneralPath;
import javax.swing.JPanel;
import org.frog.effects.Glow;

public class GlowDemo extends JFrame
{

public GlowDemo ()
{
super("Inner glow demo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

PaintCanvas pc = new PaintCanvas();
pc.setPreferredSize(new Dimension(500, 500));

getContentPane().add(pc);
pack();
setLocationRelativeTo(null);
setVisible(true);
}

public static void main (String args[])
{
new GlowDemo();
}

}


class PaintCanvas extends JPanel
{

public PaintCanvas ()
{
super();
}

@Override
public void paintComponent (Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
AffineTransform atBef = g2.getTransform();

// Circle start
g2.translate(10, 10);
Area a = new Area(new Ellipse2D.Double(0, 0, 150, 150));

// Background
g2.setBackground(new Color(28, 28, 28));
g2.fill(a);

// Circle
g2.setColor(new Color(3, 56, 89));
g2.fillOval(0, 0, 150, 150);

Glow glow = new Glow(Color.black, 40);
glow.paint(g2, a);

g2.setTransform(atBef);
// Circle end

// Star start
g2.translate(170, 10);

GeneralPath gp = new GeneralPath();
gp.moveTo(0, 51);
gp.lineTo(53, 51);
gp.lineTo(72, 0);
gp.lineTo(89, 51);
gp.lineTo(143, 51);
gp.lineTo(100, 84);
gp.lineTo(116, 135);
gp.lineTo(72, 105);
gp.lineTo(28, 135);
gp.lineTo(43, 84);
gp.lineTo(0, 51);

Area star = new Area(gp);

// Background
g2.setColor(new Color(86, 3, 89));
g2.fill(star);

// Star

Glow glow1 = new Glow(Color.red, 10);
glow1.paint(g2, new Area(gp));

g2.setTransform(atBef);
// Circle end
}

}

[dlorde]

Am I missing something, or is it supposed to just display 2 objects with an internal shading gradient?

Looks OK, although I'm pretty sure I've seen similar graphics using RadialGradientPaint.

Don't ask what it means, but rather how it is used...
L. Wittgenstein

[happy_hippie]

The paint method you gave, is only round.
Mine gives a inner glow, no matter which shape you use, which is not the same.

[happy_hippie]

And yes, it is only showing 2 shapes, to display the effect on different shapes

[dlorde]

The paint method you gave, is only round.

what? I gave no paint method. What have you been smoking?

Mine gives a inner glow, no matter which shape you use, which is not the same.

Not the same as what?

When a programming language is created that allows programmers to program in simple English, it will be discovered that programmers cannot speak English...
Anon.

[happy_hippie]

Am I missing something, or is it supposed to just display 2 objects with an internal shading gradient?

Looks OK, although I'm pretty sure I've seen similar graphics using RadialGradientPaint.

Don't ask what it means, but rather how it is used...
L. Wittgenstein

It must be you that has been smoking weed.
As i read that post, you mensions RadialGradientPaint, which is a paint, right?

dlorde:Not the same as what? | It is not a paint, but a glow.

[dlorde]

It must be you that has been smoking weed.
As i read that post, you mensions RadialGradientPaint, which is a paint, right?

It's a class that implements the Paint interface. Did you follow the link?

It is not a paint, but a glow.

Why don't you explain what you mean by a 'paint' and a 'glow' in this context and what the significant differences are between them. I ran the code you posted and saw what looked like very slight radial shading gradients in two shapes.

The limits of your language are the limits of your world...
L. Wittgenstein

[happy_hippie]

It's a class that implements the Paint interface. Did you follow the link?



Why don't you explain what you mean by a 'paint' and a 'glow' in this context and what the significant differences are between them. I ran the code you posted and saw what looked like very slight radial shading gradients in two shapes.

The limits of your language are the limits of your world...
L. Wittgenstein

Yes i did follow the link, thats why i say RadialGradientPaint is a paint, a gradient paint that is painted in a circle.
What i have provided, the Glow, is like in Photoshop, where you defines an inner glow to a shape/graphic.

[dlorde]

OK. The terminology is still opaque to me (maybe it's a PhotoShop thing?).

I guess the demo doesn't show the 'glow' to best effect.

Don't ask what it means, but rather how it is used...
L. Wittgenstein