<!DOCTYPE html>
<title>Test DOMMatrix.inverse()/invertSelf() keep is2D status</title>
<link rel="help" href="https://drafts.fxtf.org/geometry-1/#DOMMatrix">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
function check2D(m) {
  assert_true(m.is2D);
  // assert_equals() distinguish 0 and -0, so use '== 0' instead.
  assert_true(m.m13 == 0);
  assert_true(m.m14 == 0);
  assert_true(m.m23 == 0);
  assert_true(m.m24 == 0);
  assert_true(m.m31 == 0);
  assert_true(m.m32 == 0);
  assert_equals(m.m33, 1);
  assert_true(m.m34 == 0);
  assert_true(m.m43 == 0);
  assert_equals(m.m44, 1);
}

test(function() {
  for (var s = 0.1; s < 20; s += 0.1) {
    m = new DOMMatrix().scale(s, s);
    check2D(m);
    check2D(m.inverse());
    m.invertSelf();
    check2D(m);
  }
}, "scale");

test(function() {
  for (var r = 0; r < 180; r += 2) {
    m = new DOMMatrix().rotate(r);
    check2D(m);
    check2D(m.inverse());
    m.invertSelf();
    check2D(m);
  }
}, "rotate");
</script>
