<!DOCTYPE HTML>
<html>
<head>
<title>image generator for box-shadow tests</title>
<meta charset="UTF-8">
<!--

This file uses canvas to generate the images used (and checked in to
the repository) for these tests.

Since the tests are blurring a very tall (relative to the Gaussian
kernel) straight boundary, we can use a one dimensional Gaussian
function to generate the image.

We're blurring a space that has black on the left 300 pixels and white
on the right 300 pixels.  We treat pixel edges as 0, 1, 2, ..., 600 and
pixel centers as 0.5, 1.5, ..., 599.5.

Therefore we want the cumulative gaussian, with 5% slop, rounded using
floor or ceiling to provide *extra* tolerance.  This means the color
values for each pixel should be the output of the following R commands:

floor(pmax(0, pnorm(seq(0,599)+0.5, mean=300, sd=50) - 0.05) * 255)
ceiling(pmin(1, pnorm(seq(0,599)+0.5, mean=300, sd=50) + 0.05) * 255)

-->
<script>
var darker = [
 // output of
 // floor(pmax(0, pnorm(seq(0,599)+0.5, mean=300, sd=50) - 0.05) * 255)
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 1, 2, 2, 3, 3, 4, 5, 5, 6, 7, 8, 9, 9, 10, 11, 12, 13, 14,
 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 29, 30, 32, 33, 34,
 36, 37, 39, 40, 42, 43, 45, 46, 48, 49, 51, 53, 54, 56, 58, 59, 61, 63,
 65, 66, 68, 70, 72, 74, 76, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97,
 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125,
 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153,
 155, 157, 159, 160, 162, 164, 166, 168, 169, 171, 173, 174, 176, 178,
 179, 181, 182, 184, 185, 187, 188, 190, 191, 193, 194, 195, 197, 198,
 199, 201, 202, 203, 204, 205, 207, 208, 209, 210, 211, 212, 213, 214,
 215, 216, 217, 218, 218, 219, 220, 221, 222, 222, 223, 224, 224, 225,
 226, 226, 227, 227, 228, 229, 229, 230, 230, 231, 231, 232, 232, 232,
 233, 233, 234, 234, 234, 235, 235, 235, 236, 236, 236, 236, 237, 237,
 237, 237, 238, 238, 238, 238, 238, 238, 239, 239, 239, 239, 239, 239,
 239, 240, 240, 240, 240, 240, 240, 240, 240, 240, 240, 241, 241, 241,
 241, 241, 241, 241, 241, 241, 241, 241, 241, 241, 241, 241, 241, 241,
 241, 241, 241, 241, 241, 241, 241, 241, 241, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242,
 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242
];

var lighter = [
 // output of
 // ceiling(pmin(1, pnorm(seq(0,599)+0.5, mean=300, sd=50) + 0.05) * 255)
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15,
 15, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18,
 19, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 23, 23, 23, 24, 24, 25,
 25, 26, 26, 27, 28, 28, 29, 29, 30, 31, 31, 32, 33, 33, 34, 35, 36, 37,
 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 56,
 57, 58, 60, 61, 62, 64, 65, 67, 68, 70, 71, 73, 74, 76, 77, 79, 81, 82,
 84, 86, 87, 89, 91, 93, 95, 96, 98, 100, 102, 104, 106, 108, 110, 112,
 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140,
 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168,
 170, 172, 174, 176, 178, 179, 181, 183, 185, 187, 189, 190, 192, 194,
 196, 197, 199, 201, 202, 204, 206, 207, 209, 210, 212, 213, 215, 216,
 218, 219, 221, 222, 223, 225, 226, 227, 228, 230, 231, 232, 233, 234,
 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 246, 247,
 248, 249, 250, 250, 251, 252, 252, 253, 253, 254, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255
]

function append_link(arr, name) {
  if (arr.length != 600) {
    return;
  }
  var canvas = document.createElement("canvas");
  canvas.setAttribute("width", 600);
  canvas.setAttribute("height", 10);
  var cx = canvas.getContext("2d");
  for (var x = 0; x < 600; ++x) {
    var color = arr[x];
    cx.fillStyle = "rgb(" + color + "," + color + "," + color + ")";
    cx.fillRect(x, 0, 1, 10);
  }

  var a = document.createElement("a");
  a.setAttribute("href", canvas.toDataURL("image/png", ""));
  a.appendChild(document.createTextNode(name));
  var p = document.createElement("p");
  p.appendChild(a);
  document.body.appendChild(p);
}

function run() {
  append_link(darker, "box-shadow-blur-definition-001-dark-bound.png");
  append_link(lighter, "box-shadow-blur-definition-001-light-bound.png");
}

window.addEventListener("load", run);
</script>
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<body>
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