CanvasRenderingContext2D.beginPath()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨julho de 2015⁩.

O método CanvasRenderingContext2D.beginPath() da API Canvas 2D inicia um novo caminho (path), esvaziando a lista de sub-caminhos (sub-paths). Use esse método quando você quiser criar um novo path.

Sintaxe

void ctx.beginPath();

Exemplos

Usando o método `beginPath`

Isto é só um simples trecho de código que usa o método fillRect.

HTML

html

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

// Primeiro path
ctx.beginPath();
ctx.strokeStyle = "blue";
ctx.moveTo(20, 20);
ctx.lineTo(200, 20);
ctx.stroke();

// Segundo path
ctx.beginPath();
ctx.strokeStyle = "green";
ctx.moveTo(20, 20);
ctx.lineTo(120, 120);
ctx.stroke();

Edite o código abaixo e veja as alterações instantâneas no canvas:

<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
  <input id="edit" type="button" value="Edit" />
  <input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code" style="height:200px">
// First path
ctx.beginPath();
ctx.strokeStyle = 'blue';
ctx.moveTo(20,20);
ctx.lineTo(200,20);
ctx.stroke();

// Second path
ctx.beginPath();
ctx.strokeStyle = 'green';
ctx.moveTo(20,20);
ctx.lineTo(120, 120);
ctx.stroke();</textarea
>

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener("click", function () {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener("click", function () {
  textarea.focus();
});

textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);