LayoutTests/fast/canvas/gradient-with-clip_t01.dart

/*
 * Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 * for details. All rights reserved. Use of this source code is governed by a
 * BSD-style license that can be found in the LICENSE file.
 */
/** 
 * @description Test for canvas regression where gradient clips were not
 * cleared https://bugs.webkit.org/show_bug.cgi?id=21498
 */
import "dart:html";
import "dart:math" as Math;
import "../../testcommon.dart";
import "../../../Utils/async_utils.dart";

main() {
  pixelValueAt(context, x, y) {
    var imageData = context.getImageData(x, y, 1, 1);
    return imageData.data;
  }

  pixelShouldBe(context, x, y, expectedPixel) {
    var pixel = pixelValueAt(context, x, y);

    debug("pixel $x,$y");
    shouldBeList(pixel, expectedPixel);
  }

  var canvas;

  fillWithColor(context, color) {
    context.save();
    context.fillStyle = color;
    context.fillRect(0, 0, canvas.width, canvas.height);
    context.restore();
  }

  canvas = document.createElement("canvas");
  canvas.height = 100;
  canvas.width = 100;
  canvas.style.height = "100";
  canvas.style.width = "100";

  document.body.append(canvas);

  var greenImage = document.createElement("canvas");
  greenImage.height = 10;
  greenImage.width = 10;
  var greenCtx = greenImage.getContext('2d');
  fillWithColor(greenCtx, "green");
  var greenPixel = pixelValueAt(greenCtx, 0, 0);

  var ctx = canvas.getContext('2d');
  var gradient = ctx.createLinearGradient(0, 0, 10, 0);
  gradient.addColorStop(0, "blue");
  gradient.addColorStop(1, "red");
  ctx.fillStyle = gradient;
  ctx.beginPath();
  ctx.moveTo(0, 0);
  ctx.lineTo(10, 5);
  ctx.lineTo(10, 10);
  ctx.lineTo(5, 10);
  ctx.closePath();
  ctx.fill();

  ctx.fillStyle = "green";
  ctx.fillRect(20, 20, 10, 10);

  pixelShouldBe(ctx, 20, 20, greenPixel);
}