<!--
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>WebGL Transform Feedback 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>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">#version 300 es
in vec3 position;
void main()
{
    gl_Position = vec4(position, 1);
}
</script>
<script id="fshader" type="x-shader/x-fragment">#version 300 es
precision mediump float;
out vec4 color;
void main()
{
    color = vec4(0);
}
</script>
<script>
"use strict";
description("Test that specifying non-existent varyings for transform feedback causes the program to fail to link. This test covers an ANGLE bug.");

// Spec: GLES 3.0.5 section 2.12.8:
// "A program will fail to link if:"
// "any variable name specified in the varyings array is not declared as an output in the vertex shader;"

debug("");

var wtu = WebGLTestUtils;
var gl = wtu.create3DContext(undefined, undefined, 2);

if (!gl) {
    testFailed("WebGL context does not exist");
} else {
    runTest("bogus");
    runTest("gl_Bogus");
}

function runTest(nonExistentVaryingName) {
    var program = wtu.setupTransformFeedbackProgram(gl, ["vshader", "fshader"],
        [nonExistentVaryingName], gl.INTERLEAVED_ATTRIBS,
        ["position"]);
    var msg = "Program should fail to link when a nonexistent varying '" + nonExistentVaryingName + "' is specified for transform feedback.";
    if (program) {
        testFailed(msg);
    } else {
        testPassed(msg);
    }
}

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