<!--
Copyright (c) 2020 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>WebGL Texture Copying and Deletion 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="example" width="1" height="1" style="width: 40px; height: 40px;"></canvas>
<div id="description"></div>
<div id="console"></div>

<script>
"use strict";
description('Checks that texture copying and deletion work correctly together.');
debug('Regression test for <a href="http://anglebug.com/4267">http://anglebug.com/4267</a>');
const wtu = WebGLTestUtils;
const canvas = document.getElementById("example");
canvas.addEventListener('webglcontextlost', contextLost, false);

let contextWasLost = false;
function contextLost(e) {
  e.preventDefault();
  contextWasLost = true;
  debug("***context lost -- should not happen***");
}

const gl = wtu.create3DContext(canvas);

const texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 2, 2, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

const texture2 = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture2);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 2, 2, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

const framebuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
assertMsg(gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE,
    "framebuffer should be FRAMEBUFFER_COMPLETE.");
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after setup");

// This test does not call getError, because doing so seems to cause
// an implicit flush which intermittently masks the bug.

debug("");
debug("testing copyTexImage2D");
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.copyTexImage2D(gl.TEXTURE_2D, 1, gl.RGBA, 0, 0, 2, 2, 0);
// Not necessary to do any CopyTexImage2D operations to texture2.

debug("");
debug("testing copyTexSubImage2D");
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.copyTexSubImage2D(gl.TEXTURE_2D, 1, 0, 0, 0, 0, 1, 1);
gl.bindTexture(gl.TEXTURE_2D, texture2);
gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, 1, 1);

debug('deleting framebuffer');
gl.deleteFramebuffer(framebuffer);
debug('deleting texture');
gl.deleteTexture(texture);
debug('deleting texture2');
// On buggy driver, crashes during this deleteTexture call.
gl.deleteTexture(texture2);

setTimeout(function() {
  shouldBe("contextWasLost", "false");
  finishTest();
}, 1000);
</script>
</body>
</html>
