You might want to check out the java.awt.geom.GeneralPath class (which is a
Shape), then. You can use that to store the path that the ball or "point"
has followed (as line segments). Then, during your paint operation, you
just paint the shape (the GeneralPath).
-----Original Message-----
From: Jason Kretzer [mailto:jrkretzer@xxxxxxxxx]
Sent: Tuesday, March 15, 2005 9:54 AM
To: James Carman; users@xxxxxxxxxx
Subject: RE: [cinjug-users] tracing a path
It would if the application did not stop. :)
I am just trying to have little ball move across the
frame by coordinates that are calculated in a loop. I
need to leave a line behind the ball as it moves from
one position to another. Of course, once it reaches
the edge of the frame which is the terminating
condition, the ball stops.
-Jason
--- James Carman <james@xxxxxxxxxxxxxxxxxxxx> wrote:
> Are you trying to perpetually keep the path on the
> screen? So, basically,
> your screen will look like a bunch of lines after a
> while?
>
> -----Original Message-----
> From: Jason Kretzer [mailto:jrkretzer@xxxxxxxxx]
> Sent: Tuesday, March 15, 2005 9:44 AM
> To: users@xxxxxxxxxx
> Subject: Re: [cinjug-users] tracing a path
>
>
> OK, I have this part. How would one go about
> getting
> the points to stay put? After I draw a point and
> call
> repaint on the JComponent toshow that point, the
> point
> that I drew just before that disappears.
>
> To work around that I am keeping a collection of all
> points and redrawing all of them every time a new
> point needs drawn. This does OK but is terribly
> inefficient and little choppy.
>
> Basically, every time I compute a new point, I need
> it
> drawn without erasing any other previous point.
>
> Does that make sense?
>
> Thanks for your help everyone.
>
> -Jason
>
>
> --- Chris McMahan <cmcmahan@xxxxxxx> wrote:
> > The secret is to think of it not as a line, but as
> a
> > series of
> > points. The applet you pointed out is merely
> drawing
> > points on the
> > canvas at the specified interval.
> >
> > Just extract the point's position at a certain
> point
> > in your code as
> > it moves around, and draw another point at those coordinates.
> >
> > - Chris
> >
> > Jason Kretzer writes:
> > >Hello all:
> > >
> > >I am trying to draw a line behind a moving point
> so
> > as
> > >to draw the path of the point. I have looked
> > through
> > >the books that I have and I cannot seem to find
> > >exactly what I need.
> > >
> > >Here is a website that has an applet that shows
> > what I
> > >am trying to do. Notice how the path is left
> > behind
> > >the moving ball image.
> > >
> >
>
>http://www.phys.hawaii.edu/~teb/java/ntnujava/bouncingBall/bouncingBall
> >.html
> > >
> > >Any other resources would be appreciated.
> > >
> > >Thanks for the help.
> > >
> > >-Jason
> > >
> >
> > --
> > ================================
> > Chris McMahan | cmcmahan@xxxxxxx
> > ================================
> >
> >
>
>
>
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