<!--
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>WebGL Out Of VRAM 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>
<div id="description"></div>
<div id="console"></div>
<canvas id="canvas" width="2" height="2"> </canvas>
<script>
"use strict";
debug("This tests WebGL running out of vram.");

debug("");
debug("Canvas.getContext");

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
try {
  var gl = wtu.create3DContext(canvas);
} catch(e) {
}
if (!gl) {
  testFailed("could not create context");
} else {
  testPassed("context exists");

  var args = wtu.getUrlArguments();

  canvas.addEventListener('webglcontextlost', contextLost, false);

  function contextLost(e) {
    e.preventDefault();
    debug("***context lost***");
  }

  function contextRestored(e) {
    debug("***context restored***");
  }

  var program = wtu.setupTexturedQuad(gl);
  gl.useProgram(program);

  debug("");
  debug("Allocating textures.");

  var intervalId;
  var count = 0;
  var textureMem = 0;
  var textures = [];
  var size = 2048;
  var limit = (args.limit ? args.limit : 8192) * 1024 * 1024;

  debug("limit: " + InMB(limit))

  function InMB(v) {
    return "" + Math.floor(v / 1024 / 1024) + "MB";
  }

  function makeTexture() {
    if (gl.isContextLost()) {
      stop("out of memory");
      return;
    }
    ++count;
    textureMem += size * size * 4;
    if (textureMem > limit) {
      stop("reached limit");
      return;
    }
    debug ("creating texture #" + count + " mem = " + InMB(textureMem));
    var texture = gl.createTexture();
    textures.push(texture);
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D,
                  0,                 // level
                  gl.RGBA,           // internalFormat
                  size,              // width
                  size,              // height
                  0,                 // border
                  gl.RGBA,           // format
                  gl.UNSIGNED_BYTE,  // type
                  null);             // data
    var err = gl.getError();
    if (err != gl.NO_ERROR) {
      stop("got error: " + wtu.glEnumToString(gl, err));
      return;
    }
        // use the texture
    wtu.clearAndDrawUnitQuad(gl);
  }

  intervalId = window.setInterval(makeTexture, 1000 / 15);

}

function stop(msg) {
  window.clearInterval(intervalId);
  testPassed(msg);
  finishTest();
}
</script>
</body>
</html>
