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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
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<title>Negative tests for writting to a shader input with interpolation qualifier</title>
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<link rel="stylesheet" href="../../resources/glsl-feature-tests.css"/>
<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"></script>
<script src="../../js/glsl-conformance-test.js"></script>
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<!--
According to ESSL 3.00.6 section 4.3.4:
"Variables declared as in or centroid in may not be written to during shader execution.",
these tests ensure that a compile error is generated when using a shader input with interpolation qualifier as l-value.
-->
<script type="application/javascript">
"use strict";
description();

var vertexShaderTemplate = [
    '#version 300 es',
    '$(InterpolationQualifier) out float v_float_varying;',
    'void main()',
    '{',
    '    v_float_varying = 1.0;',
    '    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);',
    '}'
].join('\n');

var fragmentShaderTemplate = [
    '#version 300 es',
    'precision mediump float;',
    '$(InterpolationQualifier) in float v_float_varying;',
    'out vec4 my_color;',
    'void main()',
    '{',
    '    v_float_varying = 1.0;',
    '    my_color = vec4(1.0, 0.0, 0.0, v_float_varying);',
    '}'
].join('\n');

var errorMessageTemplate = "Writting to shader inputs with '$(InterpolationQualifier)' qualifier must fail";

var testDataList = [
{
    InterpolationQualifier: 'flat'
},
{
    InterpolationQualifier: 'smooth'
},
{
    InterpolationQualifier: 'centroid'
}
];

var wtu = WebGLTestUtils;

var tests = [];
for (var i = 0; i < testDataList.length; ++i) {
    tests.push({
        vShaderSource: wtu.replaceParams(vertexShaderTemplate, testDataList[i]),
        vShaderSuccess: true,
        fShaderSource: wtu.replaceParams(fragmentShaderTemplate, testDataList[i]),
        fShaderSuccess: false,
        linkSuccess: false,
        passMsg: wtu.replaceParams(errorMessageTemplate, testDataList[i])
    });
}

GLSLConformanceTester.runTests(tests, 2);
</script>
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