helper_functions.js

function pls_show_grid() {
  show_grid = !show_grid;
  render();
}
function addball(e) {
  e.preventDefault();
  console.log(e.target);
  console.log(e.target.x.value);
  // e.ta;
  let ball = e.target;
  new circle_thing(
    parseInt(ball.x.value),
    parseInt(ball.y.value),
    parseInt(ball.radius.value),
    "pink",
    // ball.color.value,
    [parseInt(ball.vx.value), parseInt(ball.vy.value)],
    [],
    ball.gravity.checked
  );
  console.log(renderer);
  render();
  // tick();
}
function addline(e) {
  e.preventDefault();
  console.log(e.target);
  // console.log(e.target.x.value);
  // e.ta;
  let ball = e.target;
  new line_thing(
    [parseInt(ball.Sx.value), parseInt(ball.Sy.value)],
    [parseInt(ball.Ex.value), parseInt(ball.Ey.value)],
    parseInt(ball.color.value)
  );
  console.log(renderer);
  render();
  // tick();
}

function dot(a, b) {
  return a[0] * b[0] + a[1] * b[1];
}

function mul_s_v(a, b) {
  return [a[0] * b, a[1] * b];
}
function sub_v(a, b) {
  // console.log("iwheof ", a, b);
  return [a[0] - b[0], a[1] - b[1]];
}
function add_v(a, b) {
  // console.log("iwheof ", a, b);
  return [a[0] + b[0], a[1] + b[1]];
}

function mag_cal(b) {
  // console.log("mag_cal", Math.pow(b[0], 2), Math.pow(b[0], 2));
  return Math.sqrt(Math.pow(b[0], 2) + Math.pow(b[1], 2));
}

function drawbackground() {
  ctx.fillStyle = "black";
  ctx.fillRect(0, 0, width, height);
  if (show_grid) {
    ctx.strokeStyle = "white";
    for (let i = 0; i < width / grid_dim[0]; i++) {
      ctx.beginPath();
      ctx.moveTo(grid_dim[0] * i, 0);
      ctx.lineTo(grid_dim[0] * i, canvas.height);
      ctx.stroke();
    }
    for (let i = 0; i < canvas.height / grid_dim[1]; i++) {
      ctx.beginPath();
      ctx.moveTo(0, grid_dim[1] * i);
      ctx.lineTo(width, grid_dim[1] * i);
      ctx.stroke();
    }
  }
}

function plot_vector(a, b, color) {
  ctx.strokeStyle = color;
  ctx.beginPath();
  ctx.moveTo(a[0], a[1]);
  ctx.lineTo(a[0] + b[0], a[1] + b[1]);

  // Draw the Path
  ctx.stroke();
}