<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Struct constructor highp bug.</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="canvas" width="256" height="256"> </canvas>
<div id="description"></div>
<div id="console"></div>

<script id="vshader" type="x-shader/x-vertex">
attribute vec4 a_position;
void main() {
  gl_Position = a_position;
}
</script>

<script id="fshader" type="x-shader/x-fragment">
#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif

struct Test {
  vec3 color;
};

void main() {
  vec3 color = vec3( 0.0, 1.0, 0.0 );
  Test test = Test( color );
  gl_FragColor = vec4( test.color, 1.0 );
}
</script>

<script type="application/javascript">
"use strict";
description("Struct constructors should evaluate properly.");
debug("Regression test for Three.js bug worked around in <a href='https://github.com/mrdoob/three.js/pull/7556'>https://github.com/mrdoob/three.js/pull/7556</a> that reproduced on Nexus 4 and 5 (Adreno 320 and 330).");
debug("When high precision is used in the fragment shader on these devices, bugs occur in evaluation of structs' constructors. Thanks to Mr. doob for the reduced test case.");
var wtu = WebGLTestUtils;
var gl = wtu.create3DContext("canvas");

gl.clearColor(1, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT);

var attribBuffers = wtu.setupUnitQuad(gl, 0, 1);
var program = wtu.setupProgram(gl, ['vshader', 'fshader'], ['a_position'], [0], true);
if (!program) {
  testFailed("Shader compilation/link failed");
} else {
  // Draw
  wtu.drawUnitQuad(gl);
  // Verify output
  wtu.checkCanvas(gl, [0, 255, 0, 255], "should be green");
}

finishTest();
</script>
