How can i make an ellipse with vertical lines coming out of its upper circumference towards the top of the page?

Processing Beginners
1

i want to make 5 lines to come out of the top part of the ellipse and touch the top of the page

2

Hi @chaotic.rabbit

You can use trigonometry… Means drawing the ellipse using trigonometric functions. :slight_smile:
This will give you access to specific circle/ellipse points which you can use as an anchor for your lines…

Give it a try …
https://processing.org/tutorials/trig

Cheers
— mnse

3 Likes
3

If you are using circles instead of ellipses, you can use Pitagoras Theorem (usually learnt before trigonometry).

A vertical line on X touches the circumference of radius R placed at 0,0 when

RR-XX=YY
So:
Y=sqrt(RR+X*X)

if the circle is at (cx,cy), you have to replace X with (X-cx) and Y with (Y-cy).

I used that on the nineties to draw a yin-yang in assembler without math coprocessor (my 286 had a coprocessor, but I did not understand how to use it).
Also, remember processing has a dist() function you can use if you dont want to use square roots and math.

4

here is an example with trig

size(900, 900);

float R = 300;

for (float i= 0; i <= 360; i+=7) {

  float x = cos(radians(i)) * R+width/2;
  float y = sin(radians(i)) * R+height/2;


  ellipse (x, y, 7, 7);
}