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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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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Verify that line width limits are enforced.</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="4" height="4" style="width: 40px; height: 30px;"></canvas>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";
description(document.title);
var wtu = WebGLTestUtils;
var gl = wtu.create3DContext("example");

// Query the line width range
var lineWidthRange = gl.getParameter(gl.ALIASED_LINE_WIDTH_RANGE);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be no errors.");

if (lineWidthRange[0] > 1 || lineWidthRange[1] < 1)
  testFailed("Line width range must include width 1");

// Zero, negative, or NaN values should cause an error and leave the value unchanged.
var curLineWidth = gl.getParameter(gl.LINE_WIDTH);
gl.lineWidth(0);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "Should not be able to set lineWidth to zero");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'curLineWidth'); // Previous value should be preserved

gl.lineWidth(-1);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "Should not be able to set lineWidth to a negative value");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'curLineWidth'); // Previous value should be preserved

gl.lineWidth(NaN);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "Should not be able to set lineWidth to NaN");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'curLineWidth'); // Previous value should be preserved

// Check that the line width can be set to the valid range.
gl.lineWidth(lineWidthRange[1]);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be able to set lineWidth to the max supported value");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'lineWidthRange[1]');

gl.lineWidth(lineWidthRange[0]);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be able to set lineWidth to the min supported value");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'lineWidthRange[0]');

// Checks that the line width can be set outside the supported range without error,
// and the unclamped value can be queried back.
// Yes, this is actually what the spec says should happen.
// See: https://www.khronos.org/opengles/sdk/docs/man3/html/glLineWidth.xhtml
gl.lineWidth(lineWidthRange[1]+1);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be able to set lineWidth to the above max supported value");
shouldBe('gl.getParameter(gl.LINE_WIDTH)', 'lineWidthRange[1]+1');

var successfullyParsed = true;

</script>
<script src="../../js/js-test-post.js"></script>

</body>
</html>


