/// <summary>
/// Rotates an image to the given angle at the given position.
/// </summary>
/// <param name="image">The image to rotate</param>
/// <param name="rotateAtX">The horizontal pixel coordinate at which to rotate the image.</param>
/// <param name="rotateAtY">The vertical pixel coordinate at which to rotate the image.</param>
/// <param name="angle">The angle in degrees at which to rotate the image.</param>
/// <returns>The image rotated to the given angle at the given position.</returns>
/// <remarks>
/// Based on <see href="http://www.codeproject.com/Articles/58815/C-Image-PictureBox-Rotations?msg=4155374#xx4155374xx"/>
/// </remarks>
private Bitmap RotateImage(Image image, float rotateAtX, float rotateAtY, float angle)
{
var newSize = ImageMaths.GetBoundingRotatedRectangle(image.Width, image.Height, angle);
var x = (newSize.Width - image.Width) / 2;
var y = (newSize.Height - image.Height) / 2;
// Create a new empty bitmap to hold rotated image
var newImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format32bppPArgb);
newImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
// Make a graphics object from the empty bitmap
using (var graphics = Graphics.FromImage(newImage))
{
// Reduce the jagged edge.
GraphicsHelper.SetGraphicsOptions(graphics);
// Put the rotation point in the "center" of the image
graphics.TranslateTransform(rotateAtX + x, rotateAtY + y);
// Rotate the image
graphics.RotateTransform(angle);
// Move the image back
graphics.TranslateTransform(-rotateAtX - x, -rotateAtY - y);
// Draw passed in image onto graphics object
graphics.DrawImage(image, new PointF(x, y));
}
image.Dispose();
return(newImage);
}
public void BoundingRotatedRectangleIsCalculated(int width, int height, float angle, int expectedWidth, int expectedHeight)
{
Rectangle result = ImageMaths.GetBoundingRotatedRectangle(width, height, angle);
result.Width.Should().Be(expectedWidth, "because the rotated width should have been calculated");
result.Height.Should().Be(expectedHeight, "because the rotated height should have been calculated");
}
public void ThenReturnRotatedRectangleAt00And5By2Given52And180Degrees(int degrees)
{
// Arrange // Act
var rectangle = ImageMaths.GetBoundingRotatedRectangle(5, 2, degrees);
// Assert
Assert.That(rectangle, Is.EqualTo(new Rectangle(0, 0, 5, 2)));
}
public void ThenShouldReturnRotatedRectangleAt00And7By7Given5By5AndDegrees(int degrees)
{
// Arrange // Act
var rectangle = ImageMaths.GetBoundingRotatedRectangle(5, 5, degrees);
// Assert
Assert.That(rectangle, Is.EqualTo(new Rectangle(0, 0, 7, 7)));
}
/// <summary>
/// Gets the bounding rectangle of the image based on the rotating angles.
/// </summary>
/// <param name="width">
/// The width of the image.
/// </param>
/// <param name="height">
/// The height of the image.
/// </param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private Rectangle GetBoundingRectangle(int width, int height)
{
int maxWidth = 0;
int maxHeight = 0;
List <float> angles = new List <float> {
this.CyanAngle, this.MagentaAngle, this.YellowAngle, this.KeylineAngle
};
foreach (float angle in angles)
{
Size rotatedSize = ImageMaths.GetBoundingRotatedRectangle(width, height, angle).Size;
maxWidth = Math.Max(maxWidth, rotatedSize.Width);
maxHeight = Math.Max(maxHeight, rotatedSize.Height);
}
return(new Rectangle(0, 0, maxWidth, maxHeight));
}
