How to delete arc in circle?

General Discussion Other

kartale

in General Discussion • Other • 8 months ago

Hello,

I know x1,y1 and x2,y2 so I want to delete A-B arc in circle on like this picture.How can i do it?

Thanks..

Replies(4)

asimes

Re: How to delete arc in circle?

8 months ago

Use arc(): http://processing.org/reference/arc_.html

If you know where A and B are, then I assume you know the radius of the circle. Find the angle of rotation for A and B to pass to arc() for its rotation arguments. If you don't know what I mean by the angle for A and B read this: http://processing.org/learning/trig/

Edit: That may not have been clear:

- Find the center of the circle and set that as the x and y of arc()

- Set the width and height just as you would with ellipse()

- Set the start and end rotation parameters with the angle of rotation you find. This can be calculated with atan2().

kartale

Re: Re: How to delete arc in circle?

8 months ago

thanks, I guess it will be need some calculations for find a arc of radians.But How can i find angle of rotation and start and stop points?

asimes

Re: How to delete arc in circle?

8 months ago

With atan2(). I wrote this a little while ago, it is not exactly what you need, but it shouldn't be too hard to translate:

float cx, cy;
float theta;
void setup() {
size(600, 600);
smooth();
cx = width/2;
cy = height/2;
}
void draw() {
background(255);
theta = atan2(mouseY-cy, mouseX-cx);
float px = cx+(cos(theta)*100);
float py = cy+(sin(theta)*100);
line(cx, cy, px, py);
ellipse(px, py, 10, 10);
println(degrees(theta));
}

kartale

Re: Re: How to delete arc in circle?

8 months ago

this sample was very helpful for me thanks..

Top Reply