Processing

Upper-semicircle formula code in Processing

This code draws the upper-semicircle that is a half part of the wave in Tae-Geuk symbol.

The trace of variables follows the formula: y2= sqrt(r2 – x2)  

 

float px, py;
float angle;
float radius = 100;
float frequency = 10;
float frequency2 = 2;
float x, x2;


PFont myFont;


void setup(){
  size(400, 200);
  background (127);
  myFont = createFont("verdana", 12);
  textFont(myFont);
  frameRate(10);
 
}








void draw(){
 
 
 
  background (127);
  noStroke();
  fill(255);




  float px = 0;
  while(px < 100) {
    px = px+1;
   }


  float py = 0;
  while(py < 75){
    py = py+1;
   }
 
 




  px = width/8 - cos(radians(angle))*(radius/2);
  py = 75 + sin(radians(angle))*(radius/2);




 
   rectMode(CENTER);
   fill(0);
 
   noStroke();
   ellipse(px, py, 5, 5);
   angle -= frequency;
   
   while(angle < -180){
   angle = 10;
   }
   
   


  text("y = sin x", 35, 185);
  text("px = " + px, 105, 185);
  text("py = " + py, 215, 185);


 loop();


}