/// <summary>
/// Asserts that the bitmap matches the image in the specified file.
/// </summary>
/// <param name="filename">The filename of the image to match against the bitmap.</param>
public void ShouldMatch(String filename)
{
var machineName = UltravioletTestFramework.GetSanitizedMachineName();
Directory.CreateDirectory(machineName);
var expected = (Bitmap)Image.FromFile(filename);
var filenameNoExtension = Path.GetFileNameWithoutExtension(filename);
var filenameExpected = Path.ChangeExtension(filenameNoExtension + "_Expected", "png");
SaveBitmap(expected, Path.Combine(machineName, filenameExpected));
var filenameActual = Path.ChangeExtension(filenameNoExtension + "_Actual", "png");
SaveBitmap(bitmap, Path.Combine(machineName, filenameActual));
if (expected.Width != bitmap.Width || expected.Height != bitmap.Height)
{
Assert.Fail("Images do not match due to differing dimensions");
}
var mismatchesFound = 0;
var mismatchesRequired = (Int32)((bitmap.Width * bitmap.Height) * threshold);
using (var diff = new Bitmap(expected.Width, expected.Height))
{
// Ignore pixels that are within about 1% of the expected value.
const Int32 PixelDiffThreshold = 2;
for (int y = 0; y < expected.Height; y++)
{
for (int x = 0; x < expected.Width; x++)
{
var pixelExpected = expected.GetPixel(x, y);
var pixelActual = bitmap.GetPixel(x, y);
var diffR = Math.Abs(pixelExpected.R + pixelActual.R - 2 * Math.Min(pixelExpected.R, pixelActual.R));
var diffG = Math.Abs(pixelExpected.G + pixelActual.G - 2 * Math.Min(pixelExpected.G, pixelActual.G));
var diffB = Math.Abs(pixelExpected.B + pixelActual.B - 2 * Math.Min(pixelExpected.B, pixelActual.B));
if (diffR > PixelDiffThreshold || diffG > PixelDiffThreshold || diffB > PixelDiffThreshold)
{
mismatchesFound++;
}
diff.SetPixel(x, y, System.Drawing.Color.FromArgb(255, diffR, diffG, diffB));
}
}
var filenameDiff = Path.ChangeExtension(filenameNoExtension + "_Diff", "png");
SaveBitmap(diff, Path.Combine(machineName, filenameDiff));
if (mismatchesFound > mismatchesRequired)
{
Assert.Fail("Images do not match");
}
}
}
public void SetUp()
{
Environment.CurrentDirectory = TestContext.CurrentContext.WorkDirectory;
try
{
var imageDir = Path.Combine(Environment.CurrentDirectory, UltravioletTestFramework.GetSanitizedMachineName());
foreach (var image in Directory.GetFiles(imageDir, "*.png"))
{
File.Delete(image);
}
}
catch (DirectoryNotFoundException) { }
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
}
