So I included the rendering hints like the following ones that are
commented-out. AntiAliasing makes the dashes consistently { 6, 2 } and
also fuzzies up the linework. Stroke_Pure doesn't seem to make any
difference. Nope, having cap=BUTT is the workaround solution for me.
A question though. Why should the choice of "end cap" be affecting the
rendering of a line between the end points? IMO each dash should be
unaffected by the cap, except for the dashes at each end of the line.
Seems like an undesirable "feature" to me.
-- Russell
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
// g2.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL,
RenderingHints.VALUE_STROKE_PURE);
// g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(backColor);
g2.setStroke(backStroke);
g2.draw(path);
g2.setColor(topColor);
g2.setStroke(topStroke);
g2.draw(path);
}
Jim Graham wrote:
Other things to try would be STROKE_PURE and
ANTIALIASING hints...
...jim
Russell East wrote:
Jim,
thanks for the clarification.
which release and platform is that on?
both 1.5.0_07-b03 and 1.6.0-rc-b89 on Fedora Linux, as well as
1.6.0-beta2-b85 on Windows XP
The context of this is that my "real" app is reading SVG and painting
it using java2D. The svg code looks like this:
<use xlink:href='' fill='none'
stroke='rgb(102,102,102)' stroke-width='4' stroke-linecap='round'
stroke-linejoin='round'/>
<use xlink:href='' fill='none' stroke='rgb(255,255,255)'
stroke-dasharray='4,4' stroke-width='2' stroke-linecap='round'
stroke-linejoin='round'/>
so you can see the svg itself is supplying the "round" for line cap. I
expect that I will simply have to ignore it and use "butt" instead, or
mess with the supplied dash pattern.
Curiously enough, if I save one of these SVG drawings and re-display
within Firefox, it has the exact same problem.
-- Russell
--------------------------------------------------------------------------------
Jim Graham wrote:
The CAP decoration is applied at the end of
each dash as documented (though admittedly this phrase isn't repeated
in the docs of the constructors, just the class comments and the
constants). Thus, the round caps will eat into the null space of the
dashes by half of the line width on both ends of each dash. Square
caps will also eat into the null voids of the dash pattern.
The net effect is that if you have a line width of 4 and a dash pattern
of 4,4 and a CAP of:
BUTT - lines look 4,4 dashed
SQUARE - lines look continuous with no dashing
ROUND - lines connect, but "narrow" between the dashes
You are using a line width of 2 with the pattern of 4,4 and so the
effect isn't as pronounced as those examples, but it still makes it
look like the pattern has reduced null areas. The parts where it
closes completely could be the rendering code trying to do something
sensible with a circular shape that is only 2 pixels tall - which
release and platform is that on?
In any case, try the different values for CAP and you should see the
dash open up or close more. If you then go back and modify your dash
pattern to account for the fact that the CAPs are eating into the null
space of the pattern you should be able to achieve the effect you are
looking for.
Also, ROUND caps with a line width of 2 doesn't leave much room for
"roundness". That is probably responsible for most of the
inconsistency you see on the various angles. Try a line width of at
least 3 for ROUND or use BUTT instead...
...jim
Russell East wrote:
Hi,
the attached sample app uses Java2D dash pattern to try to create a
railway pattern, but the result isn't very good.
The code is specifying the dash array as { 4.0f, 4.0f } but I'm seeing
variable results:
o on the top line it seems more like {5, 3}
o on the left line seems more like { 6, 2, 5, 3 } and
o on the bottom line does not look dashed at all
Is it something I'm doing wrong in my code, or known problem?
-- Russell
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------------------------------------------------------------------------
/*
* Copyright (C) 1999 - 2006 by Environmental Systems Research
Institute Inc.
* All Rights Reserved.
*
* N O T I C E
*
* THIS MATERIAL IS CONSIDERED A TRADE SECRET BY ESRI.
* UNAUTHORIZED ACCESS IS PROHIBITED.
*
* $Workfile:$ $Revision:$
*/
package com.esri.mc.app;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.GeneralPath;
/**
* dash lines look wrong
*/
public class RailwayLines extends JFrame {
public static void main(String[] args) {
new RailwayLines().setVisible(true);
}
public RailwayLines() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setBounds(200, 200, 500, 300);
String text = System.getProperty("java.vm.version");
this.setTitle(text);
MyCanvas canvas = new MyCanvas();
this.getContentPane().add(canvas);
}
}
final class MyCanvas extends JComponent {
private Stroke topStroke, backStroke;
private Color topColor, backColor;
private GeneralPath path;
MyCanvas() {
topStroke = constructTopStroke();
backStroke = constructBackStroke();
topColor = Color.WHITE;
backColor = new Color(102, 102, 102);
path = constructPath();
}
private GeneralPath constructPath() {
GeneralPath path = new GeneralPath();
path.moveTo(100.0f, 100.0f);
path.lineTo(200.0f, 200.0f);
path.lineTo(400.0f, 200.0f);
path.lineTo(400.0f, 100.0f);
path.closePath();
return path;
}
private Stroke constructBackStroke() {
float width = 4.0f;
int cap = BasicStroke.CAP_ROUND;
int join = BasicStroke.JOIN_ROUND;
return new BasicStroke(width, cap, join);
}
private Stroke constructTopStroke() {
float width = 2.0f;
int cap = BasicStroke.CAP_ROUND;
int join = BasicStroke.JOIN_ROUND;
float miterLimit = 10.f;
float[] dash = { 4.0f, 4.0f };
float dashPhase = 0.0f;
return new BasicStroke(width, cap, join, miterLimit, dash,
dashPhase);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setColor(backColor);
g2.setStroke(backStroke);
g2.draw(path);
g2.setColor(topColor);
g2.setStroke(topStroke);
g2.draw(path);
}
}
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the
body of the message "signoff JAVA2D-INTEREST". For general help, send
email to [EMAIL PROTECTED] and include in the body of the message
"help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff JAVA2D-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
|
