Drawing line, wave etc... According to equation?
Hello friends,
I was playing with graphics 2d and i require some help.
how to draw onto the pixel.?
I tried
g2.draw((Shape)new Point2D.Float(x, y));
here x ,y changes according to an equation.
but i got exception.
how can we draw on to a specific pixel.
g2.draw(new Line2D.Float(x, y, x, y));
gave me the expected result. but not Satisfactory...
as equation give only specific points and not all the points on the track.
and if i go by precision values say by 0.001 , it takes too much time to render.
i want to draw a sine wave and every point on the wave should be render. How can i achieve it.
thanks.
[757 byte] By [
Avinash.Ka] at [2007-11-27 8:24:12]
# 1
> I tried
> > g2.draw((Shape)new Point2D.Float(x, y));
>
OMG !
Look at javadoc. Point2D.Float is NOT a Shape. New to OO programming ?
>
> but i got exception.
>
yep.
> how can we draw on to a specific pixel.
Look at javadoc
> Satisfactory...
> as equation give only specific points and not all the
> points on the track.
> and if i go by precision values say by 0.001 , it
> takes too much time to render.
You cannot have 0.001 precision on screen since pixel coordinates are integer values. New to Math studies ?
Compute each Y for each integer X => you have a points
> i want to draw a sine wave and every point on the
> wave should be render. How can i achieve it.
New to Algorithm ?
Loop X from 0 to w where w is the desired width in pixels.
Compute Y for each X ; Draw a line between last 2 points.
You know what ? it works not only for sin !
> thanks.
Your welcome.
# 3
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
Path2D.Double path = new Path2D.Double();
double scale = 100; //choose the appropriate scale;
double offsetX = 100; // choose the appropriate offset;
double offsetY = 100;
path.moveTo(offsetX, offsetY);
for (double t = 0.1; t < Math.PI; t += 0.1) {
path.lineTo(offsetX + scale * t, offsetY -scale * Math.sin(t));
}
g2.draw(path);
}
# 4
hi Kilwch
thanks for ur reply.
> > I tried
> > > > g2.draw((Shape)new Point2D.Float(x, y));
> >
ya i admit it was my mistake or weirdness to do that.
>
> > Satisfactory...
> > as equation give only specific points and not all
> the
> > points on the track.
> > and if i go by precision values say by 0.001 , it
> > takes too much time to render.
> You cannot have 0.001 precision on screen since pixel
> coordinates are integer values. New to Math studies
> ?
here u misinterpreted me. here i was not saying of co-ordinates but the angle for sine wave.
see my code
double y=0, x=0;
for(int i=0;i<50000;i++)
{
y = 10*Math.sin(x);
System.out.println("cordinates ( "+ i+" ' "+y+" )");
g2.draw(newLine2D.Double(i/1000+150,y+200,i/1000+150,y+200));
x=x+.001;
}
now u would understand..
> Compute each Y for each integer X => you have a
> points
> > i want to draw a sine wave and every point on the
> > wave should be render. How can i achieve it.
> New to Algorithm ?
> Loop X from 0 to w where w is the desired width in
> pixels.
> Compute Y for each X ; Draw a line between last 2
> points.
> You know what ? it works not only for sin !
yes I know that. But that does not give smooth curve.
for eg. say for equation x = y*y;
we get points
0,0
1,1
2,4
3,9
4,16
......
and if we join them we don't get a smooth curve...
