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<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>
<title>bindAttribLocation with nonexistent attribute name</title>
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<body>
<div id="description"></div>
<div id="console"></div>
<canvas id="canvas" width="8" height="8"></canvas>
<script id="vertexShader" type="text/something-not-javascript">
precision highp float;
attribute vec4 attr;
void main() {
    gl_Position = vec4(attr);
}
</script>
<script>
"use strict";
description("This test verifies that calling bindAttribLocation with a non-existent attribute location is fine.");

// OpenGL ES 2.0.25 section 2.10 page 34.

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas);
var fragmentShader = wtu.loadShader(gl, wtu.simpleColorFragmentShader, gl.FRAGMENT_SHADER);
var vertexShader = wtu.loadShaderFromScript(gl, 'vertexShader', gl.VERTEX_SHADER);
assertMsg(vertexShader != null, "Vertex shader compiled successfully.");

var checkAttribLocation = function(program, expectedLocation) {
    var location = gl.getAttribLocation(program, 'attr');
    if (location != expectedLocation) {
        testFailed('Unexpected location for attr: ' + location);
    } else {
        testPassed('Location of attr is: ' + location);
    }
}

var testProgramNonExistentAttributeBound = function() {
    var program = gl.createProgram();
    gl.bindAttribLocation(program, 0, 'attr');
    gl.bindAttribLocation(program, 1, 'bogus_attr');
    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);
    gl.linkProgram(program);
    var linkStatus = gl.getProgramParameter(program, gl.LINK_STATUS);
    expectTrue(linkStatus, "Link should succeed even if a non-existent attribute is bound.");
    if (linkStatus) {
        checkAttribLocation(program, 0);
    }
};
var testProgramNonExistentAttributeOverlap = function() {
    var program = gl.createProgram();
    gl.bindAttribLocation(program, 1, 'attr');
    gl.bindAttribLocation(program, 1, 'bogus_attr');
    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);
    gl.linkProgram(program);
    var linkStatus = gl.getProgramParameter(program, gl.LINK_STATUS);
    expectTrue(linkStatus, "Link should succeed even if a non-existent attribute is bound to the same location as an attribute that's present in the shader text.");
    if (linkStatus) {
        checkAttribLocation(program, 1);
    }
};

testProgramNonExistentAttributeBound();
testProgramNonExistentAttributeOverlap();

var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>
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