1 files changed, 55 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/transformations/2d.transformation.setTransform.skewed.html b/testing/web-platform/tests/html/canvas/offscreen/transformations/2d.transformation.setTransform.skewed.html
new file mode 100644
index 0000000000..2d24d61f4b
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/transformations/2d.transformation.setTransform.skewed.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.transformation.setTransform.skewed</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.transformation.setTransform.skewed</h1>
+<p class="desc"></p>
+
+
+<script>
+var t = async_test("");
+var t_pass = t.done.bind(t);
+var t_fail = t.step_func(function(reason) {
+    throw reason;
+});
+t.step(function() {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  // Create green with a red square ring inside it
+  ctx.fillStyle = '#0f0';
+  ctx.fillRect(0, 0, 100, 50);
+  ctx.fillStyle = '#f00';
+  ctx.fillRect(20, 10, 60, 30);
+  ctx.fillStyle = '#0f0';
+  ctx.fillRect(40, 20, 20, 10);
+
+  // Draw a skewed shape to fill that gap, to make sure it is aligned correctly
+  ctx.setTransform(1,4, 2,3, 5,6);
+  // Post-transform coordinates:
+  //   [[20,10],[80,10],[80,40],[20,40],[20,10],[40,20],[40,30],[60,30],[60,20],[40,20],[20,10]];
+  // Hence pre-transform coordinates:
+  var pts=[[-7.4,11.2],[-43.4,59.2],[-31.4,53.2],[4.6,5.2],[-7.4,11.2],
+           [-15.4,25.2],[-11.4,23.2],[-23.4,39.2],[-27.4,41.2],[-15.4,25.2],
+           [-7.4,11.2]];
+  ctx.beginPath();
+  ctx.moveTo(pts[0][0], pts[0][1]);
+  for (var i = 0; i < pts.length; ++i)
+      ctx.lineTo(pts[i][0], pts[i][1]);
+  ctx.fill();
+  _assertPixel(canvas, 21,11, 0,255,0,255);
+  _assertPixel(canvas, 79,11, 0,255,0,255);
+  _assertPixel(canvas, 21,39, 0,255,0,255);
+  _assertPixel(canvas, 79,39, 0,255,0,255);
+  _assertPixel(canvas, 39,19, 0,255,0,255);
+  _assertPixel(canvas, 61,19, 0,255,0,255);
+  _assertPixel(canvas, 39,31, 0,255,0,255);
+  _assertPixel(canvas, 61,31, 0,255,0,255);
+  t.done();
+
+});
+</script>