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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
found in the LICENSE.txt file.
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL 2 Conformance Test: readPixels from RGB8 Buffer Into Pixel Pack Buffer.</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"></canvas>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";

debug("");
description("Verifies readPixels from RGB8 buffer into PIXEL_PACK buffer works");

debug("On MacOSX with AMD GPUs, the alpha channel is readback as 0 instead of 255");

var wtu = WebGLTestUtils;
var pixel = [0, 0, 0, 0];
var expectedColor = [255, 102, 0, 255];

var canvas = document.getElementById("example");
var gl = wtu.create3DContext(canvas, undefined, 2);

if (!gl) {
  testFailed("context does not exist");
} else {
  testPassed("context exists");

  var width = 4;
  var height = 4;

  var renderbuffer = gl.createRenderbuffer();
  gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
  gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGB8, width, height);

  var fbo = gl.createFramebuffer();
  gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
  gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, renderbuffer);

  if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE) {
    testFailed("framebuffer with RGB8 color buffer is incomplete");
  } else {
    gl.clearColor(1.0, 0.0, 0.0, 1.0);
    gl.clear(gl.COLOR_BUFFER_BIT);

    var pbo = gl.createBuffer();
    gl.bindBuffer(gl.PIXEL_PACK_BUFFER, pbo);
    gl.bufferData(gl.PIXEL_PACK_BUFFER, width * height * 4, gl.STATIC_COPY);

    gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, 0);

    var data = new Uint8Array(width * height * 4);
    gl.getBufferSubData(gl.PIXEL_PACK_BUFFER, 0, data);

    for (var ii = 0; ii < width * height; ++ii) {
      if (data[ii * 4] != 255 ||
          data[ii * 4 + 1] != 0 ||
          data[ii * 4 + 2] != 0 ||
          data[ii * 4 + 3] != 255) {
        testFailed("Expected in pixel " + ii + ": [255,0,0,255], got: " +
                   [data[ii * 4], data[ii * 4 + 1], data[ii * 4 + 2], data[ii * 4 + 3]]);
        break;
      }
    }
  }
  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Tests should complete without gl errors");
}

debug("");
var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>
</body>
</html>
