CanvasRenderingContext2D.rect()

The CanvasRenderingContext2D.rect() method of the Canvas 2D API creates a path for a rectangle at position (x, y) with a size that is determined by width and height. Those four points are connected by straight lines and the sub-path is marked as closed, so that you can fill or stroke this rectangle.

Syntax

void ctx.rect(x, y, width, height);

Parameters

x

The x coordinate for the left side of the rectangle.

y

The y coordinate for the top of the rectangle.

width

The rectangle's width.

height

The rectangle's height.

Examples

Using the rect method

This is just a simple code snippet which uses the rect method to create a path. To actually draw that path onto the canvas, you can use the fill() or stroke() method. See also the fillRect() and strokeRect() methods, which can do this in one step.

HTML

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

JavaScript

var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
ctx.rect(10, 10, 100, 100);
ctx.fill();

Edit the code below and see your changes update live in the 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">
ctx.rect(10, 10, 100, 100);
ctx.fill();</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);

Specifications

Browser compatibility

See also

• The interface defining it, CanvasRenderingContext2D
• CanvasRenderingContext2D.fillRect
• CanvasRenderingContext2D.strokeRect()
• CanvasRenderingContext2D.fill()
• CanvasRenderingContext2D.stroke()