/// <summary>
/// Creates a copy of the given bitmap after rotation using the supplied intermediate resolution
/// and Angle. Positive Angle is Clockwise. The resulting image has the same horizonatal
/// and vertical resolution as the given page, but geometry may have changed (height and width).
/// </summary>
/// <param name="bmp">The Bitmap to rotate</param>
/// <param name="intermediateResolution">The intermediate resolution to use.</param>
/// <param name="rotationAngle">The angle to rotate the image</param>
/// <returns></returns>
public static Bitmap CreateCopyRotate(Bitmap bmp, float rotationAngle)
{
PageInfo bmpinfo = new PageInfo(bmp);
PointF[] pts = new PointF[4];
pts[0] = new PointF(0, 0);
pts[1] = new PointF(bmpinfo.WidthInches, 0);
pts[2] = new PointF(0, bmpinfo.HeightInches);
pts[3] = new PointF(bmpinfo.WidthInches, bmpinfo.HeightInches);
Matrix mx = new Matrix();
mx.RotateAt(rotationAngle, new Point(0, 0), MatrixOrder.Append);
mx.TransformPoints(pts);
float width;
float height;
float dx;
float dy;
BitmapHelper.GetExtents(pts, out width, out height, out dx, out dy);
//If the overall image is bigger than 5000 pixels in either direction, then lets scale it by adjusting the Intermediate resolution - We'll scale it to about 4000 px.
float intermediateResolution = Math.Max(bmp.VerticalResolution, bmp.HorizontalResolution);
if (Math.Max(bmpinfo.WidthPixels, bmpinfo.HeightPixels) > 5000)
{
intermediateResolution = (float)(int)(4000 / Math.Max(bmpinfo.HeightInches, bmpinfo.WidthInches));
}
mx.Translate((int)(dx * intermediateResolution), (int)(dy * intermediateResolution), MatrixOrder.Append);
//Flip width and height
Bitmap temp = BitmapHelper.CreateBitMap(width, height, intermediateResolution, intermediateResolution, PixelFormat.Format32bppArgb);
{
Graphics g = Graphics.FromImage(temp);
g.ResetTransform();
g.Transform = mx;
g.DrawImage(bmp, new Point(0, 0));
g.Dispose();
}
Bitmap ret = BitmapHelper.CreateBitMap(width, height, bmpinfo.HorizontalResolution, bmpinfo.VerticalResolution, PixelFormat.Format32bppArgb);
{
Graphics g = Graphics.FromImage(ret);
g.ResetTransform();
g.DrawImage(temp, new Point(0, 0));
g.Dispose();
}
temp.Dispose();
return(ret);
}