element-array-buffer-delete-recreate.html

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Copyright (c) 2019 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.

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<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

  <title>Element Array Buffer Deletion and Recreation Test</title>

  <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>

<canvas id="example" width="32" height="32"></canvas>

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

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

<script>

"use strict";

var wtu = WebGLTestUtils;

function init()

  description();

  // Clear the background with red.

  var gl = wtu.create3DContext("example");

  wtu.setupSimpleColorProgram(gl);

  var color = [0, 255, 0, 255];

  wtu.setUByteDrawColor(gl, color);

  var vertexBuffer = gl.createBuffer();

  gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);

  gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([

    -1, -1,

     1, -1,

    -1,  1,

     1,  1

  ]), gl.STATIC_DRAW);

  gl.enableVertexAttribArray(0);

  gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);

  // Create an element array buffer.

  var indexBuffer = gl.createBuffer();

  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);

  gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint8Array([0, 1, 2, 3]), gl.STATIC_DRAW);

  // Delete the element array buffer.

  gl.deleteBuffer(indexBuffer);

  // Create a new element array buffer.

  indexBuffer = gl.createBuffer();

  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);

  gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint8Array([0, 1, 2, 3]), gl.STATIC_DRAW);

  // Draw with the new element array buffer.

  // If the geometry is drawn successfully, the fragment shader will color it green.

  gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_BYTE, 0);

  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "no errors from draw");

  wtu.checkCanvas(gl, color, "should be green")

init();

var successfullyParsed = true;

</script>

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

</body>

</html>