i have a some question for my algorithm to make a circle , this is my circle algorithm :

import processing.opengl.*;

static int canvasX = 600;
static int canvasY = 600;
void setup()
{
  size(canvasX, canvasY);
  background(255);
}

//--------------------------------- variable global ditulis disini
int x1 = 3;
int y1 = 7;
int x2 = 12;
int y2 = 15;
int dx;int dy; int x; int y; int end; float p;

int r1=0; int r2=0;int jari2 = 90; int jarix=100; int jariy=90; 




void draw() {
  drawHelpLines(); 
  stdPoint(x1, y1);
  stdPoint(x2, y2);
  lingkaran_utama(r1,r2,jari2);
 
}


void stdPoint(int xxx, int yyy)
{
  point(xxx+(canvasX/2), (yyy*-1)+(canvasY/2));
}

void drawHelpLines()
{
  stroke(0, 0, 255);
  for (int z=0; z<canvasX; z=z+1) {
    point((canvasX/2), z);
    point(z, (canvasY/2));
  }
  stroke(0, 0, 0);
}
 

void lingkaran_utama (int pusat1, int pusat2, int radius color col){
  x=0;
  y= radius;
  p = 1-radius;
  lingkaran1(pusat1,pusat2,x ,y);
 
  while (x<y)
      {
     
      if (p<0)
          {
            x++;
            lingkaran1(pusat1,pusat2,x ,y); //ambil nilai (X,Y)
            p =p+(2*x)+1;
          }
      else
          {
            x++;
            y--;
            lingkaran1(pusat1,pusat2,x ,y); //ambil nilai (x,y)
            p= p + (2*x)- (2*y) +1;
          }
     
      }
}


void lingkaran1 (int X_center, int Y_center,int x , int y){
  stdPoint (X_center + x, Y_center + y);
  stdPoint (X_center - x, Y_center + y);
  stdPoint (X_center + x, Y_center - y);
  stdPoint (X_center - x, Y_center - y);
  stdPoint (X_center + y, Y_center + x);
  stdPoint (X_center - y, Y_center + x);
  stdPoint (X_center + y, Y_center - x);
  stdPoint (X_center - y, Y_center - x);
 
}

for this algorithm, i confused to fiilling the circle area .
and i confused too to make the line of circle be dash dot, long dash, etc
i confused that what algorithm i must use ?
Help me please
Can you help me please  ?