<!--
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>Matrix compound multiplication test</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 vec3 aPosition;

void main() {
    gl_Position = vec4(aPosition, 1);
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;

void main() {
    $(type) a = $(type)(0.0);
    $(type) b = $(type)(0.0);
    a[1][1] = 3.0; // 2nd column, 2nd row
    b[0][1] = 2.0; // 1st column, 2nd row
    $(type) c = a * b;
    a *= b;
    $(type) diffMat = a - c;
    float diff = length(diffMat[0]) + length(diffMat[1]);
    gl_FragColor = vec4(0.0, diff < 0.01 ? 1.0 : 0.0, 0.0, 1.0);
}
</script>
<script type="application/javascript">
"use strict";
description("Matrix compound multiplication test comparing against normal multiplication.");
debug("");
var wtu = WebGLTestUtils;
function test() {
  var gl = wtu.create3DContext("canvas");
  if (!gl) {
    testFailed("context does not exist");
    return;
  }
  wtu.setupUnitQuad(gl);
  var fshaderTemplate = wtu.getScript('fshader');

  var types = ['mat2', 'mat3', 'mat4'];
  for (var i = 0; i < types.length; ++i) {
    debug('');
    debug('Testing type ' + types[i]);
    var fshaderSource = wtu.replaceParams(fshaderTemplate, {type: types[i]});
    var program = wtu.setupProgram(gl, ['vshader', fshaderSource], ["aPosition"], undefined, true);
    wtu.drawUnitQuad(gl);
    wtu.checkCanvas(gl, [0, 255, 0, 255], 'should be green');
  }
};

test();
finishTest();
</script>
</body>
</html>
