h=500

O = [w/2, h/2];

s = 1;

class matrix {

  constructor(a11, a12, a21, a22) {

    this.a11 = a11;

    this.a12 = a12;

    this.a21 = a21;

    this.a22 = a22

  }

  mul(v){

    return new punkt(this.a11*v.x+this.a12*v.y,this.a21*v.x+this.a22*v.y)

  }

}

class punkt {

  constructor(x, y) {

    this.x = x;

    this.y = y;

  }

  tegn() {

    point(O[0] + this.x, O[1] - this.y);

  }

  mul(A) {

    let a = this.x;

    let b = this.y;

    this.x = A.a11 * a + A.a12 * b;

    this.y = A.a21 * a + A.a22 * b;

  }

}

function matmul(A, v) {

  return new punkt(A.a11* v.x + A.a12 * v.y, A.a21 * v.x + A.a22 * v.y);

}

function rot(t){

  return new matrix(cos(t),-sin(t),sin(t),cos(t))

}

let uc = [];

let A;

let n = 0;

let u=0

let r=0

let tuc=[]

let d=0

function setup() {

  createCanvas(w, h);

  A = new matrix(1, 0, 0, 1);

}

​

function draw() {

  background(220);

  stroke(150)

  line(0,h/2,w,h/2)

  line(w/2,0,w/2,h)

  line((w-h)/2,h,(w+h)/2,0)

  line((w-h)/2,0,(w+h)/2,h)

  noFill()

  circle(w/2,h/2,h)

  if (mouseIsPressed) {

    if (uc.length <= n) {

      uc.push([]);

      tuc.push([])

    } else {

      uc[n].push(new punkt(mouseX - O[0], O[1] - mouseY));

      tuc[n].push(A.mul(new punkt(mouseX - O[0], O[1] - mouseY)))

    }

  } else {

    n = uc.length + 1;

  }

  for (let j = 0; j < uc.length; j++) {

    for (let i = 0; i < uc[j].length - 1; i++) {

      stroke('green')

      line(

        O[0] + uc[j][i].x,

        O[1] - uc[j][i].y,

        O[0] + uc[j][i + 1].x,

        O[1] - uc[j][i + 1].y

      );

      stroke('red')

      line(

        O[0] + tuc[j][i].x,

        O[1] - tuc[j][i].y,

        O[0] + tuc[j][i + 1].x,

        O[1] - tuc[j][i + 1].y

      );

    }

  }

    A.a11+=pow(0,!keyIsDown(UP_ARROW)+!keyIsDown(LEFT_ARROW))*pow(-1,keyIsDown(SHIFT))/100

    A.a12+=pow(0,!keyIsDown(UP_ARROW)+!keyIsDown(RIGHT_ARROW))*pow(-1,keyIsDown(SHIFT))/100

    A.a21+=pow(0,!keyIsDown(DOWN_ARROW)+!keyIsDown(LEFT_ARROW))*pow(-1,keyIsDown(SHIFT))/100

    A.a22+=pow(0,!keyIsDown(DOWN_ARROW)+!keyIsDown(RIGHT_ARROW))*pow(-1,keyIsDown(SHIFT))/100

  for (let j = 0; j < uc.length; j++) {

    for (let i = 0; i < uc[j].length; i++) {

      tuc[j][i]=A.mul(uc[j][i])

      uc[j][i].x+=r

      uc[j][i].y+=u

    }

  }

  if(keyIsDown(90)&&keyIsDown(CONTROL)&&d==0){

    uc.pop()

    tuc.pop()

    n=uc.length+1

    d=1

  }else if(!keyIsDown(90)){d=0}

  stroke('black')

  textSize(20)

  text('A=('+round(A.a11,2)+','+round(A.a12,2)+','+round(A.a21,2)+','+round(A.a22,2)+')',20,20)

}