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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>WebGL vertex_array_object Conformance Tests</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>
<div id="description"></div>
<canvas id="canvas" style="width: 50px; height: 50px;"> </canvas>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">
attribute vec4 a_position;
attribute vec4 a_color;
varying vec4 v_color;
void main(void) {
gl_Position = a_position;
v_color = a_color;
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
varying vec4 v_color;
void main(void) {
gl_FragColor = v_color;
}
</script>
<script>
"use strict";
description("This test verifies the functionality of the Vertex Array Objects.");
debug("");
var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas, null, 2);
var vao = null;
if (!gl) {
testFailed("WebGL context does not exist");
} else {
testPassed("WebGL context exists");
runBindingTest();
runObjectTest();
runAttributeTests();
runAttributeValueTests();
runDrawTests();
runUnboundDeleteTests();
runBoundDeleteTests();
runArrayBufferBindTests();
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "there should be no errors");
}
function runBindingTest() {
debug("Testing binding enum");
shouldBe("gl.VERTEX_ARRAY_BINDING", "0x85B5");
gl.getParameter(gl.VERTEX_ARRAY_BINDING);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "VERTEX_ARRAY_BINDING query should succeed");
// Default value is null
if (gl.getParameter(gl.VERTEX_ARRAY_BINDING) === null) {
testPassed("Default value of VERTEX_ARRAY_BINDING is null");
} else {
testFailed("Default value of VERTEX_ARRAY_BINDING is not null");
}
debug("Testing binding a VAO");
var vao0 = gl.createVertexArray();
var vao1 = gl.createVertexArray();
shouldBeNull("gl.getParameter(gl.VERTEX_ARRAY_BINDING)");
gl.bindVertexArray(vao0);
if (gl.getParameter(gl.VERTEX_ARRAY_BINDING) == vao0) {
testPassed("gl.getParameter(gl.VERTEX_ARRAY_BINDING) is expected VAO");
} else {
testFailed("gl.getParameter(gl.VERTEX_ARRAY_BINDING) is not expected VAO")
}
gl.bindVertexArray(vao1);
if (gl.getParameter(gl.VERTEX_ARRAY_BINDING) == vao1) {
testPassed("gl.getParameter(gl.VERTEX_ARRAY_BINDING) is expected VAO");
} else {
testFailed("gl.getParameter(gl.VERTEX_ARRAY_BINDING) is not expected VAO")
}
gl.deleteVertexArray(vao1);
shouldBeNull("gl.getParameter(gl.VERTEX_ARRAY_BINDING)");
gl.bindVertexArray(vao1);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "binding a deleted vertex array object");
gl.bindVertexArray(null);
shouldBeNull("gl.getParameter(gl.VERTEX_ARRAY_BINDING)");
gl.deleteVertexArray(vao1);
}
function runObjectTest() {
debug("Testing object creation");
vao = gl.createVertexArray();
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "createVertexArray should not set an error");
shouldBeNonNull("vao");
// Expect false if never bound
shouldBeFalse("gl.isVertexArray(vao)");
gl.bindVertexArray(vao);
shouldBeTrue("gl.isVertexArray(vao)");
gl.bindVertexArray(null);
shouldBeTrue("gl.isVertexArray(vao)");
shouldBeFalse("gl.isVertexArray(null)");
gl.deleteVertexArray(vao);
vao = null;
}
function runAttributeTests() {
debug("Testing attributes work across bindings");
var states = [];
var attrCount = gl.getParameter(gl.MAX_VERTEX_ATTRIBS);
for (var n = 0; n < attrCount; n++) {
gl.bindBuffer(gl.ARRAY_BUFFER, null);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);
var state = {};
states.push(state);
var vao = state.vao = gl.createVertexArray();
gl.bindVertexArray(vao);
var enableArray = (n % 2 == 0);
if (enableArray) {
gl.enableVertexAttribArray(n);
} else {
gl.disableVertexAttribArray(n);
}
if (enableArray) {
var buffer = state.buffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, 1024, gl.STATIC_DRAW);
gl.vertexAttribPointer(n, 1 + n % 4, gl.FLOAT, true, n * 4, n * 4);
}
if (enableArray) {
var elbuffer = state.elbuffer = gl.createBuffer();
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elbuffer);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, 1024, gl.STATIC_DRAW);
}
gl.bindVertexArray(null);
}
var anyMismatch = false;
for (var n = 0; n < attrCount; n++) {
var state = states[n];
gl.bindVertexArray(state.vao);
var shouldBeEnabled = (n % 2 == 0);
var isEnabled = gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_ENABLED);
if (shouldBeEnabled != isEnabled) {
testFailed("VERTEX_ATTRIB_ARRAY_ENABLED not preserved");
anyMismatch = true;
}
var buffer = gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_BUFFER_BINDING);
if (shouldBeEnabled) {
if (buffer == state.buffer) {
// Matched
if ((gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_SIZE) == 1 + n % 4) &&
(gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_TYPE) == gl.FLOAT) &&
(gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_NORMALIZED) == true) &&
(gl.getVertexAttrib(n, gl.VERTEX_ATTRIB_ARRAY_STRIDE) == n * 4) &&
(gl.getVertexAttribOffset(n, gl.VERTEX_ATTRIB_ARRAY_POINTER) == n * 4)) {
// Matched
} else {
testFailed("VERTEX_ATTRIB_ARRAY_* not preserved");
anyMismatch = true;
}
} else {
testFailed("VERTEX_ATTRIB_ARRAY_BUFFER_BINDING not preserved");
anyMismatch = true;
}
} else {
// GL_CURRENT_VERTEX_ATTRIB is not preserved
if (buffer) {
testFailed("VERTEX_ATTRIB_ARRAY_BUFFER_BINDING not preserved");
anyMismatch = true;
}
}
var elbuffer = gl.getParameter(gl.ELEMENT_ARRAY_BUFFER_BINDING);
if (shouldBeEnabled) {
if (elbuffer == state.elbuffer) {
// Matched
} else {
testFailed("ELEMENT_ARRAY_BUFFER_BINDING not preserved");
anyMismatch = true;
}
} else {
if (elbuffer == null) {
// Matched
} else {
testFailed("ELEMENT_ARRAY_BUFFER_BINDING not preserved");
anyMismatch = true;
}
}
}
gl.bindVertexArray(null);
if (!anyMismatch) {
testPassed("All attributes preserved across bindings");
}
for (var n = 0; n < attrCount; n++) {
var state = states[n];
gl.deleteVertexArray(state.vao);
}
}
function runAttributeValueTests() {
debug("Testing that attribute values are not attached to bindings");
var v;
var vao0 = gl.createVertexArray();
var anyFailed = false;
gl.bindVertexArray(null);
gl.vertexAttrib4f(0, 0, 1, 2, 3);
v = gl.getVertexAttrib(0, gl.CURRENT_VERTEX_ATTRIB);
if (!(v[0] == 0 && v[1] == 1 && v[2] == 2 && v[3] == 3)) {
testFailed("Vertex attrib value not round-tripped?");
anyFailed = true;
}
gl.bindVertexArray(vao0);
v = gl.getVertexAttrib(0, gl.CURRENT_VERTEX_ATTRIB);
if (!(v[0] == 0 && v[1] == 1 && v[2] == 2 && v[3] == 3)) {
testFailed("Vertex attrib value reset across bindings");
anyFailed = true;
}
gl.vertexAttrib4f(0, 4, 5, 6, 7);
gl.bindVertexArray(null);
v = gl.getVertexAttrib(0, gl.CURRENT_VERTEX_ATTRIB);
if (!(v[0] == 4 && v[1] == 5 && v[2] == 6 && v[3] == 7)) {
testFailed("Vertex attrib value bound to buffer");
anyFailed = true;
}
if (!anyFailed) {
testPassed("Vertex attribute values are not attached to bindings")
}
gl.bindVertexArray(null);
gl.deleteVertexArray(vao0);
}
function runDrawTests() {
debug("Testing draws with various VAO bindings");
canvas.width = 50; canvas.height = 50;
gl.viewport(0, 0, canvas.width, canvas.height);
var vao0 = gl.createVertexArray();
var vao1 = gl.createVertexArray();
var opt_positionLocation = 0;
var opt_texcoordLocation = 1;
var program = wtu.setupSimpleTextureProgram(gl, opt_positionLocation, opt_texcoordLocation);
function setupQuad(s) {
var vertexObject = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
1.0 * s, 1.0 * s, 0.0,
-1.0 * s, 1.0 * s, 0.0,
-1.0 * s, -1.0 * s, 0.0,
1.0 * s, 1.0 * s, 0.0,
-1.0 * s, -1.0 * s, 0.0,
1.0 * s, -1.0 * s, 0.0]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(opt_positionLocation);
gl.vertexAttribPointer(opt_positionLocation, 3, gl.FLOAT, false, 0, 0);
var vertexObject = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
1.0 * s, 1.0 * s,
0.0 * s, 1.0 * s,
0.0 * s, 0.0 * s,
1.0 * s, 1.0 * s,
0.0 * s, 0.0 * s,
1.0 * s, 0.0 * s]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(opt_texcoordLocation);
gl.vertexAttribPointer(opt_texcoordLocation, 2, gl.FLOAT, false, 0, 0);
};
function readLocation(x, y) {
var pixels = new Uint8Array(1 * 1 * 4);
gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
return pixels;
};
function testPixel(blockList, allowList) {
function testList(list, expected) {
for (var n = 0; n < list.length; n++) {
var l = list[n];
var x = -Math.floor(l * canvas.width / 2) + canvas.width / 2;
var y = -Math.floor(l * canvas.height / 2) + canvas.height / 2;
var source = readLocation(x, y);
if (Math.abs(source[0] - expected) > 2) {
return false;
}
}
return true;
}
return testList(blockList, 0) && testList(allowList, 255);
};
function verifyDraw(drawNumber, s) {
wtu.clearAndDrawUnitQuad(gl);
var blockList = [];
var allowList = [];
var points = [0.0, 0.2, 0.4, 0.6, 0.8, 1.0];
for (var n = 0; n < points.length; n++) {
if (points[n] <= s) {
blockList.push(points[n]);
} else {
allowList.push(points[n]);
}
}
if (testPixel(blockList, allowList)) {
testPassed("Draw " + drawNumber + " passed pixel test");
} else {
testFailed("Draw " + drawNumber + " failed pixel test");
}
};
// Setup all bindings
setupQuad(1);
gl.bindVertexArray(vao0);
setupQuad(0.5);
gl.bindVertexArray(vao1);
setupQuad(0.25);
// Verify drawing
gl.bindVertexArray(null);
verifyDraw(0, 1);
gl.bindVertexArray(vao0);
verifyDraw(1, 0.5);
gl.bindVertexArray(vao1);
verifyDraw(2, 0.25);
gl.bindVertexArray(null);
gl.deleteVertexArray(vao0);
gl.deleteVertexArray(vao1);
// Disable global vertex attrib array
gl.disableVertexAttribArray(opt_positionLocation);
gl.disableVertexAttribArray(opt_texcoordLocation);
// Draw with values.
var positionLoc = 0;
var colorLoc = 1;
var gridRes = 1;
wtu.setupIndexedQuad(gl, gridRes, positionLoc);
// Set the vertex color to red.
gl.vertexAttrib4f(colorLoc, 1, 0, 0, 1);
var vao0 = gl.createVertexArray();
gl.bindVertexArray(vao0);
var program = wtu.setupSimpleVertexColorProgram(gl, positionLoc, colorLoc);
wtu.setupIndexedQuad(gl, gridRes, positionLoc);
// Set the vertex color to green.
gl.vertexAttrib4f(colorLoc, 0, 1, 0, 1);
wtu.clearAndDrawIndexedQuad(gl, gridRes);
wtu.checkCanvas(gl, [0, 255, 0, 255], "should be green")
gl.deleteVertexArray(vao0);
wtu.clearAndDrawIndexedQuad(gl, gridRes);
wtu.checkCanvas(gl, [0, 255, 0, 255], "should be green")
}
function runUnboundDeleteTests() {
debug("Testing using buffers that are deleted when attached to unbound VAOs");
var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["a_position", "a_color"]);
gl.useProgram(program);
var positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.bufferData(
gl.ARRAY_BUFFER,
new Float32Array([
1.0, 1.0,
-1.0, 1.0,
-1.0, -1.0,
1.0, -1.0]),
gl.STATIC_DRAW);
var colors = [
[255, 0, 0, 255],
[ 0, 255, 0, 255],
[ 0, 0, 255, 255],
[ 0, 255, 255, 255]
];
var colorBuffers = [];
var elementBuffers = [];
var vaos = [];
for (var ii = 0; ii < colors.length; ++ii) {
var vao = gl.createVertexArray();
vaos.push(vao);
gl.bindVertexArray(vao);
// Set the position buffer
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
var elementBuffer = gl.createBuffer();
elementBuffers.push(elementBuffer);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
gl.bufferData(
gl.ELEMENT_ARRAY_BUFFER,
new Uint8Array([0, 1, 2, 0, 2, 3]),
gl.STATIC_DRAW);
// Setup the color attrib
var color = colors[ii];
if (ii < 3) {
var colorBuffer = gl.createBuffer();
colorBuffers.push(colorBuffer);
gl.bindBuffer(gl.ARRAY_BUFFER, colorBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array(
[ color[0], color[1], color[2], color[3],
color[0], color[1], color[2], color[3],
color[0], color[1], color[2], color[3],
color[0], color[1], color[2], color[3]
]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(1);
gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, true, 0, 0);
} else {
gl.vertexAttrib4f(1, color[0] / 255, color[1] / 255, color[2] / 255, color[3] / 255);
}
}
// delete the color buffers AND the position buffer.
gl.bindVertexArray(null);
for (var ii = 0; ii < colorBuffers.length; ++ii) {
gl.deleteBuffer(colorBuffers[ii]);
gl.deleteBuffer(elementBuffers[ii]);
gl.bindVertexArray(vaos[ii]);
var boundBuffer = gl.getVertexAttrib(1, gl.VERTEX_ATTRIB_ARRAY_BUFFER_BINDING);
// The buffers should still be valid at this point, since it was attached to the VAO
if(boundBuffer != colorBuffers[ii]) {
testFailed("buffer removed too early");
}
}
gl.bindVertexArray(null);
gl.deleteBuffer(positionBuffer);
// Render with the deleted buffers. As they are referenced by VAOs they
// must still be around.
for (var ii = 0; ii < colors.length; ++ii) {
var color = colors[ii];
gl.bindVertexArray(vaos[ii]);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_BYTE, 0);
wtu.checkCanvas(gl, color, "should be " + color);
}
// Clean up.
for (var ii = 0; ii < colorBuffers.length; ++ii) {
gl.deleteVertexArray(vaos[ii]);
}
for (var ii = 0; ii < colorBuffers.length; ++ii) {
// The buffers should no longer be valid now that the VAOs are deleted
if(gl.isBuffer(colorBuffers[ii])) {
testFailed("buffer not properly cleaned up after VAO deletion");
}
}
}
function runBoundDeleteTests() {
debug("Testing using buffers that are deleted when attached to bound VAOs");
var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["a_position", "a_color"]);
gl.useProgram(program);
var positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.bufferData(
gl.ARRAY_BUFFER,
new Float32Array([
1.0, 1.0,
-1.0, 1.0,
-1.0, -1.0,
1.0, -1.0]),
gl.STATIC_DRAW);
// Setup the color attrib
var colorBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, colorBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array(
[ 255, 0, 0, 255,
0, 255, 0, 255,
0, 0, 255, 255,
0, 255, 255, 255
]), gl.STATIC_DRAW);
var vaos = [];
var elementBuffers = [];
for (var ii = 0; ii < 4; ++ii) {
var vao = gl.createVertexArray();
vaos.push(vao);
gl.bindVertexArray(vao);
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
var elementBuffer = gl.createBuffer();
elementBuffers.push(elementBuffer);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
gl.bufferData(
gl.ELEMENT_ARRAY_BUFFER,
new Uint8Array([0, 1, 2, 0, 2, 3]),
gl.STATIC_DRAW);
gl.bindBuffer(gl.ARRAY_BUFFER, colorBuffer);
gl.enableVertexAttribArray(1);
gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, true, 0, 0);
}
// delete the color buffers AND the position buffer, that are bound to the current VAO
for (var ii = 0; ii < vaos.length; ++ii) {
gl.bindVertexArray(vaos[ii]);
gl.deleteBuffer(colorBuffer);
gl.deleteBuffer(positionBuffer);
// After the first iteration, deleteBuffer will be a no-op, and will not unbind its matching
// bind points on the now-bound VAO like it did on the first iteration.
var expectRetained = (ii != 0);
var shouldBeStr = (expectRetained ? "retained" : "cleared");
var boundPositionBuffer = gl.getVertexAttrib(0, gl.VERTEX_ATTRIB_ARRAY_BUFFER_BINDING);
if (expectRetained != (boundPositionBuffer == positionBuffer)) {
testFailed("Position attrib stored buffer should be " + shouldBeStr + ".");
}
var boundColorBuffer = gl.getVertexAttrib(1, gl.VERTEX_ATTRIB_ARRAY_BUFFER_BINDING);
if (expectRetained != (boundColorBuffer == colorBuffer)) {
testFailed("Color attrib stored buffer should be " + shouldBeStr + ".");
}
// If retained, everything should still work. If cleared, drawing should now fail.
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_BYTE, 0);
var expectedError = (expectRetained ? gl.NO_ERROR : gl.INVALID_OPERATION);
wtu.glErrorShouldBe(gl, expectedError,
"Draw call should " + (expectRetained ? "not " : "") + "fail.");
if (gl.isBuffer(positionBuffer)) {
testFailed("References from unbound VAOs don't keep Position buffer alive.");
}
if (gl.isBuffer(colorBuffer)) {
testFailed("References from unbound VAOs don't keep Color buffer alive");
}
}
}
function runArrayBufferBindTests() {
debug("Testing that VAOs don't effect ARRAY_BUFFER binding.");
gl.bindVertexArray(null);
var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["a_color", "a_position"]);
gl.useProgram(program);
// create shared element buuffer
var elementBuffer = gl.createBuffer();
// bind to default
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
gl.bufferData(
gl.ELEMENT_ARRAY_BUFFER,
new Uint8Array([0, 1, 2, 0, 2, 3]),
gl.STATIC_DRAW);
// first create the buffers for no vao draw.
var nonVAOColorBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, nonVAOColorBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array(
[ 0, 255, 0, 255,
0, 255, 0, 255,
0, 255, 0, 255,
0, 255, 0, 255,
]), gl.STATIC_DRAW);
// shared position buffer.
var positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.bufferData(
gl.ARRAY_BUFFER,
new Float32Array([
1.0, 1.0,
-1.0, 1.0,
-1.0, -1.0,
1.0, -1.0]),
gl.STATIC_DRAW);
// attach position buffer to default
gl.enableVertexAttribArray(1);
gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, 0);
// now create vao
var vao = gl.createVertexArray();
gl.bindVertexArray(vao);
// attach the position buffer vao
gl.enableVertexAttribArray(1);
gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, 0);
var vaoColorBuffer = gl.createBuffer();
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 4, gl.UNSIGNED_BYTE, true, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, vaoColorBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array(
[ 255, 0, 0, 255,
255, 0, 0, 255,
255, 0, 0, 255,
255, 0, 0, 255,
]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 4, gl.UNSIGNED_BYTE, true, 0, 0);
// now set the buffer back to the nonVAOColorBuffer
gl.bindBuffer(gl.ARRAY_BUFFER, nonVAOColorBuffer);
// bind to vao
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_BYTE, 0);
wtu.checkCanvas(gl, [255, 0, 0, 255], "should be red");
// unbind vao
gl.bindVertexArray(null);
// At this point the nonVAOColorBuffer should be still be bound.
// If the WebGL impl is emulating VAOs it must make sure
// it correctly restores this binding.
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 4, gl.UNSIGNED_BYTE, true, 0, 0);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_BYTE, 0);
wtu.checkCanvas(gl, [0, 255, 0, 255], "should be green");
}
debug("");
var successfullyParsed = true;
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