Zooming in on specific point. (Translate and scale)

p5.js Coding Questions
5

This inspired me.
I have come across this before and like to “scale” the plot that I draw and not use scale();
Not p5.js but an example.

Example with embellishments (translating, scaling and some)

long time, timeLast;
float scale = 1;
float theta;
float x,  y;

void setup()
  {
  size(1000, 1000);  
  time = 1000;
  timeLast = millis();
  }
  
void draw()
  {  
  background(0);
   
  translate(width/2, height/2);

// Rotates in a circle  
  theta += TAU/500;
  x = 150*sin(3*theta);
  y = 150*cos(3*theta);
  translate(x, y);
  
//  if (timeLast + time < millis())  //Remove comment to see this effect
    { 
    timeLast = millis();  
    //scale = 50;
    // modulating scale
    scale = 10*(sin(theta)+1);
    }
    
    for(float x = 0; x < TAU; x+= TAU/(scale*10) )
      {
      float y = 5*sin(x);
      stroke(255, 255, 0);
      strokeWeight(3);
      point(scale*x,scale*y);
      stroke(255);
      line (0, -10*scale, 0, +10*scale);
      line (0, 0, 10*scale, 0);
      }
  println(frameRate);    
  }