/// <summary>
/// Performs scale-to-fit operations on the <c>Metafile</c> object.
/// </summary>
/// <param name="pageSettings">The <c>PageSettings</c> object used for printing.</param>
/// <param name="graphics">The <c>Graphics</c> object used for printing.</param>
/// <param name="metafile">The <c>Metafile</c> object that is to be scaled.</param>
/// <returns>A <c>Point</c> array containing a single value that designates the position where the bottom corner of the metafile image is to be stretched.</returns>
public static Point[] ScaleToFitMetafileForPrinting(PageSettings pageSettings, Graphics graphics, Metafile metafile)
{
if (pageSettings == null)
{
throw new ArgumentNullException(nameof(pageSettings));
}
if (graphics == null)
{
throw new ArgumentNullException(nameof(graphics));
}
if (metafile == null)
{
throw new ArgumentNullException(nameof(metafile));
}
if (pageSettings.PaperSize == null)
{
throw new ArgumentNullException("pageSettings.PaperSize");
}
if (pageSettings.PaperSize.Height <= 0)
{
throw new ArgumentNullException("pageSettings.PaperSize.Height");
}
if (pageSettings.PaperSize.Width <= 0)
{
throw new ArgumentNullException("pageSettings.PaperSize.Width");
}
var points = new[] { new Point(0, 0) };
try
{
if (metafile != null)
{
var metafileHeader = metafile.GetMetafileHeader();
// get the sizes of the image and the current printer settings printable area
var metafileDpi = new SizeF(metafileHeader.DpiX, metafileHeader.DpiY);
var paperSize = new SizeF(pageSettings.PaperSize.Width, pageSettings.PaperSize.Height);
// get the factor by which to scale the metafile
var dpiFactor = metafileDpi.DivideBy(ScaleToFitHelper.DesiredPrintDpi);
// account for the normalization in the graphic object
graphics.ScaleTransform(dpiFactor.Width, dpiFactor.Height, MatrixOrder.Prepend);
var metafileSizeNormalized = metafile.Size.ToSizeF().DivideBy(ScaleToFitHelper.DesiredPrintDpi).MultiplyBy(Constants.HundredthInchFactor);
// By default if no scaling is required, we don't want the scale to affect the values in the matrix.
float scaleToFitFactor = 1;
// If the printer is set to Landscape then we need to swap the width and height values
var metafileSizeOriented = pageSettings.Landscape ? metafileSizeNormalized.ToggleOrientation() : metafileSizeNormalized;
// Does the normalized and oriented metafile fit inside the paper size?
// (The metafile should cover over the entire page, including hard margins.)
if (!metafileSizeOriented.FitsInside(paperSize))
{
// must perform scale to fit operation, now update the scale to fit factor
scaleToFitFactor = paperSize.DivideBy(metafileSizeOriented).GetSmallestSide();
}
// we now have all the information we need to scale
graphics.ScaleTransform(scaleToFitFactor, scaleToFitFactor, MatrixOrder.Append);
// Shift the metafile by hard margin size to align to top left side of paper.
int hardMarginOffsetX = (int)pageSettings.HardMarginX * -1;
int hardMarginOffsetY = (int)pageSettings.HardMarginY * -1;
points = new[] { new Point(hardMarginOffsetX, hardMarginOffsetY) };
var matrix = graphics.Transform;
matrix.Invert();
matrix.TransformPoints(points);
}
}
catch (Exception ex)
{
// TODO Error Log
throw ex;
}
return(points);
}
