LayoutTests/fast/canvas/canvas-strokePath-shadow_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 Ensure correct behavior of canvas with path stroke shadow
 */
import "dart:html";
import "dart:math" as Math;
import "../../testcommon.dart";
import "../../../Utils/async_utils.dart";

main() {
  // Level of tolerance we expect of most pixel comparisons in this test.
  shouldBeAlmost(_a, _b) => shouldBeCloseTo(_a, _b, 2);

  var canvas = document.createElement('canvas');
  document.body.append(canvas);
  canvas.setAttribute('width', '700');
  canvas.setAttribute('height', '700');
  var ctx = canvas.getContext('2d');

  ctx.beginPath();
  ctx.moveTo(300, 300);
  ctx.lineTo(300, 50);
  ctx.bezierCurveTo(200, 40, 75, 150, 30, 30);
  ctx.quadraticCurveTo(250, 75, 50, 300);
  ctx.shadowOffsetX = 350;
  ctx.shadowColor = 'rgba(255, 20, 0, 0.5)';
  ctx.shadowBlur = 0;
  ctx.strokeStyle = 'rgba(0, 0, 255, 1)';
  ctx.lineWidth = 30;
  ctx.closePath();
  ctx.stroke();

  ctx.beginPath();
  ctx.moveTo(300,650);
  ctx.lineTo(300,400);
  ctx.bezierCurveTo(200, 390, 75, 500, 30, 380);
  ctx.quadraticCurveTo(250, 425, 50, 650);
  ctx.shadowOffsetX = 350;
  ctx.shadowColor = 'rgba(255, 0, 0, 0.5)';
  ctx.shadowBlur = 30;
  ctx.strokeStyle = 'rgba(0, 0, 255, 1)';
  ctx.lineWidth = 30;
  ctx.closePath();
  ctx.stroke();

  var imageData, data;

  // Verify solid shadow.
  imageData = ctx.getImageData(650, 300, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 20);
  shouldBeAlmost(data[2], 0);

  imageData = ctx.getImageData(650, 50, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 20);
  shouldBeAlmost(data[2], 0);

  imageData = ctx.getImageData(380, 30, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 20);
  shouldBeAlmost(data[2], 0);

  imageData = ctx.getImageData(400, 40, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 20);
  shouldBeAlmost(data[2], 0);

  // Verify blurry shadow.
  imageData = ctx.getImageData(640, 640, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 0);
  shouldBeAlmost(data[2], 0);
  shouldNotBe(data[3], 255);

  imageData = ctx.getImageData(650, 400, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 0);
  shouldBeAlmost(data[2], 0);
  shouldNotBe(data[3], 255);

  imageData = ctx.getImageData(380, 380, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 0);
  shouldBeAlmost(data[2], 0);
  shouldNotBe(data[3], 255);

  imageData = ctx.getImageData(350, 380, 1, 1);
  data = imageData.data;
  shouldBeAlmost(data[0], 255);
  shouldBeAlmost(data[1], 0);
  shouldBeAlmost(data[2], 0);
  shouldNotBe(data[3], 255);
}