Rendering text more than once in the same position
Qu0ll
the same text in the same position twice or more without clearing the
background? I would have thought that it's the exact same pixels affected
and therefore the text would still look as sharp as if it were only rendered
once. I am suspecting it has something to do with antialiasing. Correct?
--
And loving it,
-Qu0ll (Rare, not extinct)
_________________________________________________
Qu0llS...@gmail.com
[Replace the "SixFour" with numbers to email me]
John B. Matthews
In article
<4927bbf2$0$7520$5a62...@per-qv1-newsreader-01.iinet.net.au>,
"Qu0ll" <Qu0llS...@gmail.com> wrote:
> Why is it that the text appears smudged when you use drawString() to render
> the same text in the same position twice or more without clearing the
> background? I would have thought that it's the exact same pixels affected
> and therefore the text would still look as sharp as if it were only rendered
> once. I am suspecting it has something to do with antialiasing. Correct?
I am unable to reproduce this at any scale on Mac OS 10.5 Java 1.5.
<code>
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TransTest extends JFrame {
private class MyPanel extends JPanel {
@Override
public void paintComponent(final Graphics g) {
final Graphics2D g2d = (Graphics2D)g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
final double scaleX = this.getWidth() / 100.0;
final double scaleY = this.getHeight() / 100.0;
final BasicStroke stroke = new BasicStroke(4f,
BasicStroke.CAP_ROUND , BasicStroke.JOIN_ROUND);
g2d.setStroke(stroke);
final AffineTransform at = new AffineTransform(
AffineTransform.getScaleInstance(scaleX, scaleY));
at.translate(10, 10);
g2d.transform(at);
g2d.setColor(new Color(128, 64, 32));
g2d.drawRect(0, 0, 80, 80);
line(g2d, 0, 0, 80, 80);
line(g2d, 0, 40, 80, 40);
line(g2d, 40, 0, 40, 80);
line(g2d, 0, 0, 80, 80);
line(g2d, 80, 0, 0, 80);
g2d.setColor(Color.darkGray);
g2d.drawString("Test/", 5, 65);
g2d.drawString("Test\\", 5, 65);
}
}
private void line(Graphics2D g2, int x1, int y1, int x2, int y2) {
Color color = g2.getColor();
g2.setColor(color.brighter());
g2.drawLine(x1, y1, x2, y2);
}
public TransTest() {
this.setLayout(new BorderLayout());
final MyPanel panel = new MyPanel();
this.add(panel, BorderLayout.CENTER);
panel.setBackground(Color.WHITE);
this.pack();
this.setSize(543, 567);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
}
public static void main(final String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
new TransTest().setVisible(true);
}
});
}
}
</code>
--
John B. Matthews
trashgod at gmail dot com
http://home.roadrunner.com/~jbmatthews/
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Qu0ll
news:nospam-2AED2A....@news.motzarella.org...
[...]
> I am unable to reproduce this at any scale on Mac OS 10.5 Java 1.5.
Try the following. The first line of text appears smudged with Java 6u10.
[code]
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TransTest2 extends JFrame {
private class MyPanel extends JPanel {
@Override
public void paintComponent(final Graphics g) {
final Graphics2D g2d = (Graphics2D)g;
g2d
.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(Color.darkGray);
g2d.setFont(new Font("Arial", Font.PLAIN, 24));
g2d.drawString("Test", 5, 65);
g2d.drawString("Test", 5, 65);
g2d.drawString("Test", 5, 95);
}
}
public TransTest2() {
this.setLayout(new BorderLayout());
final MyPanel panel = new MyPanel();
this.add(panel, BorderLayout.CENTER);
panel.setBackground(Color.WHITE);
this.pack();
this.setSize(543, 567);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
}
public static void main(final String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
new TransTest2().setVisible(true);
}
});
}
}
[/code]
John B. Matthews
<49285e02$0$7519$5a62...@per-qv1-newsreader-01.iinet.net.au>,
"Qu0ll" <Qu0llS...@gmail.com> wrote:
> "John B. Matthews" <nos...@nospam.invalid> wrote in message
> news:nospam-2AED2A....@news.motzarella.org...
>
> [...]
>
> > I am unable to reproduce this at any scale on Mac OS 10.5 Java 1.5.
>
> Try the following. The first line of text appears smudged with Java
> 6u10.
Wait, I took pictures (click to enlarge):
<http://sites.google.com/site/trashgod/transtest3>
It _is_ a shade weightier, especially at low point size. I jammed up the
baselines to exaggerate the effect. I can't tell if it's a bug or a
feature: it reminds me of overstriking a daisy wheel to get bold.
I wonder what yours looks like (hint, hint).
[...]
John B. Matthews
"John B. Matthews" <nos...@nospam.invalid> wrote:
> In article
> <49285e02$0$7519$5a62...@per-qv1-newsreader-01.iinet.net.au>,
> "Qu0ll" <Qu0llS...@gmail.com> wrote:
>
> > "John B. Matthews" <nos...@nospam.invalid> wrote in message
> > news:nospam-2AED2A....@news.motzarella.org...
> >
> > [...]
> >
> > > I am unable to reproduce this at any scale on Mac OS 10.5 Java 1.5.
> >
> > Try the following. The first line of text appears smudged with Java
> > 6u10.
>
> Wait, I took pictures (click to enlarge):
>
> <http://sites.google.com/site/trashgod/transtest3>
>
> It _is_ a shade weightier, especially at low point size. I jammed up the
> baselines to exaggerate the effect. I can't tell if it's a bug or a
> feature: it reminds me of overstriking a daisy wheel to get bold.
>
> I wonder what yours looks like (hint, hint).
D'oh, of course it's smudged: anti-aliasing is a function of the
background, which changes on each pass. Try a dozen or so to see the
effect.
Qu0ll
As I suspected, antialiasing was the cause - I just didn't know why. Now
it's obvious, thanks John.
Andrew Thompson
...
> As I suspected, antialiasing was the cause - I just didn't know why. Now
> it's obvious, thanks John.
And now the question is answered, might you divulge
why on earth this text is being written twice? Seems
a waste of CPU cycles (before we even get to the
blurred effect).
--
Andrew Thompson
http://pscode.org/
Qu0ll
news:75e874f6-5fed-4fd6...@a37g2000pre.googlegroups.com...
It's complex. I have a situation where text is being drawn onto a
translucent graphical object which in turn is sitting in front of an
animation. I want the text to be superimposed over the graphic but the
graphic sometimes gets re-rendered when part of the animation crosses under
it. Basically I keep having to redraw the text because I cannot be sure
when the underlying graphic is re-rendered which clears the text. I could
force a repaint of the graphic but then I would have to repaint that part of
the animation and the entire surrounding panel, neither of which the text
knows anything about.
Andrew Thompson
..
> ...Basically I keep having to redraw the text because I cannot be sure
> when the underlying graphic is re-rendered which clears the text.
Odd situation. In that event I would paint the string
to a BufferedImage (with the appropriate transparency)
and paint the BI each time.
OK - you probably figured that already, but I just
thought it worth stating for later searches.