<html>
  <head>
    <meta charset='UTF-8'>
    <script src='/tests/SimpleTest/SimpleTest.js'></script>
    <link rel='stylesheet' href='/tests/SimpleTest/test.css'>
  </head>
  <body>
<canvas id='c' width='200' height='200'></canvas>
<canvas id='c2' width='200' height='200'></canvas>

<script>

function RGBAToString(arr) {
  return '[' + arr[0].toPrecision(4) + ', ' +
               arr[1].toPrecision(4) + ', ' +
               arr[2].toPrecision(4) + ', ' +
               arr[3].toPrecision(4) + ']';
}

function TestScreenColor(gl, r, g, b, a) {
  var arr = new SharedArrayBuffer(4);
  var view = new Uint8Array(arr);
  gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, view);

  var err = gl.getError();
  ok(err == 0, 'Should be no errors.');
  if (err)
    return;

  var floatArr;
  floatArr = new Float32Array(4);
  floatArr[0] = view[0] / 255.0;
  floatArr[1] = view[1] / 255.0;
  floatArr[2] = view[2] / 255.0;
  floatArr[3] = view[3] / 255.0;

  var testText = RGBAToString(floatArr);
  var refText = RGBAToString([r, g, b, a]);

  var eps = 1.0 / 255.0;
  var isSame = (Math.abs(floatArr[0] - r) < eps &&
                Math.abs(floatArr[1] - g) < eps &&
                Math.abs(floatArr[2] - b) < eps &&
                Math.abs(floatArr[3] - a) < eps);

  ok(isSame, 'Should be ' + refText + ', was ' + testText + ',');
}

// Give ourselves a scope to return early from:
(function() {
  var canvas = document.getElementById('c');
  var attribs = {
    antialias: false,
    depth: false,
  };
  let gl = canvas.getContext('experimental-webgl', attribs);
  if (!gl) {
    todo(false, 'WebGL is unavailable.');
    return;
  }
  if (typeof SharedArrayBuffer === 'undefined') {
    todo(false, 'SharedArrayBuffer is unavailable.');
    return;
  }

  var vs = gl.createShader(gl.VERTEX_SHADER);
  gl.shaderSource(vs, "attribute vec2 aVertCoord; void main(void) { gl_Position = vec4(aVertCoord, 0.0, 1.0); }");
  gl.compileShader(vs);
  var fs = gl.createShader(gl.FRAGMENT_SHADER);
  gl.shaderSource(fs, "precision mediump float; uniform vec4 uFragColor; void main(void) { gl_FragColor = uFragColor; }");
  gl.compileShader(fs);
  var prog = gl.createProgram();
  gl.attachShader(prog, vs);
  gl.attachShader(prog, fs);
  gl.linkProgram(prog);

  var success = gl.getProgramParameter(prog, gl.LINK_STATUS);
  if (!success) {
    console.log('Error linking program for \'' + vsId + '\' and \'' + fsId + '\'.');
    console.log('\nLink log: ' + gl.getProgramInfoLog(prog));
    console.log('\nVert shader log: ' + gl.getShaderInfoLog(vs));
    console.log('\nFrag shader log: ' + gl.getShaderInfoLog(fs));
  }
  ok(prog, 'Program should link.');
  if (!prog) {
    return;
  }

  prog.aVertCoord = gl.getAttribLocation(prog, 'aVertCoord');
  prog.uFragColor = gl.getUniformLocation(prog, 'uFragColor');

  gl.useProgram(prog);

  // Test gl.bufferData(), gl.bufferSubData() and gl.readPixels() APIs with SAB as input.
  var arr = new SharedArrayBuffer(8*4);
  var view = new Float32Array(arr);
  view.set(new Float32Array([-1, -1, 1, -1, -1,  1, 1,  1]));
  var vb = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, vb);
  gl.bufferData(gl.ARRAY_BUFFER, view, gl.STATIC_DRAW);
  ok(gl.getError() == 0, 'bufferData with SAB as input parameter works ok.');
  gl.bufferSubData(gl.ARRAY_BUFFER, 0, view);
  ok(gl.getError() == 0, 'bufferSubData with SAB as input parameter works ok.');
  gl.enableVertexAttribArray(0);
  gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
  gl.clearColor(0, 0, 0, 1.0);
  gl.clear(gl.COLOR_BUFFER_BIT);
  gl.uniform4f(prog.uFragColor, 0.2, 0.4, 0.6, 1.0);
  gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
  var arr = new Uint8Array(4);
  TestScreenColor(gl, 0.2, 0.4, 0.6, 1.0);

  // Test gl.texImage2D() and gl.texSubImage2D() APIs with SAB as input.
  var tex = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_2D, tex);
  var width = 4;
  var height = 4;
  var numChannels = 4;
  var sab = new SharedArrayBuffer(width * height * numChannels);
  var data = new Uint8Array(sab);
  for (var i = 0; i < data.length; ++i) {
    data[i] = i;
  }
  gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, data);
  ok(gl.getError() == 0, 'texImage2D() with SAB as input parameter works ok.');
  gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, data);
  ok(gl.getError() == 0, 'texSubImage2D() with SAB as input parameter works ok.');

  ok(gl.getError() == 0, 'Should be no errors after test.');
})();

// Test WebGL 2
(function() {
  var canvas = document.getElementById('c2');
  var attribs = {
    antialias: false,
    depth: false,
  };
  let gl = canvas.getContext('webgl2', attribs);
  if (!gl) {
    todo(false, 'WebGL 2 is unavailable.');
    return;
  }
  if (typeof SharedArrayBuffer === 'undefined') {
    todo(false, 'SharedArrayBuffer is unavailable.');
    return;
  }

  var arr = new SharedArrayBuffer(8*4);
  var view = new Float32Array(arr);
  view.set(new Float32Array([-1, -1, 1, -1, -1,  1, 1,  1]));
  var vb = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, vb);
  gl.bufferData(gl.ARRAY_BUFFER, view, gl.STATIC_DRAW);

  var arr2 = new SharedArrayBuffer(8*4);
  var view2 = new Float32Array(arr2);
  gl.getBufferSubData(gl.ARRAY_BUFFER, 0, view2);
  var equal = true;
  for(var i = 0; i < 8; ++i) {
    if (view[i] != view2[i]) equal = false;
  }
  ok(equal, 'getBufferSubData with SAB as input parameter works ok.');

  // Test gl.texImage3D() and gl.texSubImage3D() APIs with SAB as input.
  var tex = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_3D, tex);
  var width = 4;
  var height = 4;
  var depth = 4;
  var numChannels = 4;
  var sab = new SharedArrayBuffer(width * height * depth* numChannels);
  var data = new Uint8Array(sab);
  for (var i = 0; i < data.length; ++i) {
    data[i] = i;
  }
  gl.texImage3D(gl.TEXTURE_3D, 0, gl.RGBA, width, height, depth, 0, gl.RGBA, gl.UNSIGNED_BYTE, data);
  ok(gl.getError() == 0, 'texImage3D() with SAB as input parameter works ok.');
  gl.texSubImage3D(gl.TEXTURE_3D, 0, 0, 0, 0, width, height, depth, gl.RGBA, gl.UNSIGNED_BYTE, data);
  ok(gl.getError() == 0, 'texSubImage3D() with SAB as input parameter works ok.');

  ok(gl.getError() == 0, 'Should be no errors after test.');
})();

ok(true, 'TEST COMPLETE');

</script>

  </body>
</html>
