<!--
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.
-->
<!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>
