zero-sized-canvas.html

Enable keyboard shortcuts

<!--

Copyright (c) 2020 The Khronos Group Inc.

Use of this source code is governed by an MIT-style license that can be

found in the LICENSE.txt file.

-->

<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

<link rel="stylesheet" href="../../resources/js-test-style.css"/>

<script src="../../js/js-test-pre.js"></script>

<script src="../../js/webgl-test-utils.js"></script>

</head>

<body>

<div id="description"></div>

<div id="console"></div>

<script>

"use strict";

// Global declarations so that "shouldBe" can eval with them:

let gl;

(function() {

    description('Check that zero-sized canvases work with WebGL.');

    testZero();

    finishTest();

})();

function testZero() {

    const canvas = document.createElement('canvas');

    canvas.width = 0;

    canvas.height = 0;

    gl = WebGLTestUtils.create3DContext(canvas);

    expectTrue(gl, `Context creation with ${canvas.width}x${canvas.height} canvas should succeed.`);

    shouldBe('gl.drawingBufferWidth', '1');

    shouldBe('gl.drawingBufferHeight', '1');

    shouldBeFalse('gl.isContextLost()');

    const version = gl.getParameter(gl.VERSION);

    expectTrue(version && version.length, `getParameter() should return something.`);

    debug('canvas.width = 2');

    canvas.width = 2;

    shouldBe('gl.drawingBufferWidth', '2');

    shouldBeFalse('gl.isContextLost()');

    debug('canvas.width = 0');

    canvas.width = 0;

    shouldBe('gl.drawingBufferWidth', '1');

    shouldBeFalse('gl.isContextLost()');

</script>

</body>

</html>