//// This code is part of Document Solutions for Imaging demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System;using System.IO;using System.Drawing;using System.Numerics;using GrapeCity.Documents.Drawing;using GrapeCity.Documents.Text;using GrapeCity.Documents.Imaging;using GCTEXT = GrapeCity.Documents.Text;using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsImagingWeb.Demos{    // This example shows how to create a semi-transparent blurred shadow    // of a text and graphics image, offset by a specified amount.    // To achieve this the code employs the ApplyGaussianBlur and ToShadowBitmap    // methods of the GrayscaleBitmap class.    public class Shadow    {        private GCTEXT.Font _font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeSans.ttf"));
        public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)        {            // Create a transparent bitmap and draw the shadow image on it (offset left/down by 30/50):            var bmp = new GcBitmap(pixelSize.Width, pixelSize.Height, false);            using (var g = bmp.CreateGraphics(Color.Transparent))            {                Draw(g, 30, 50);            }
            // Extract the alpha channel from GcBitmap to a GrayscaleBitmap:            using var gs = bmp.ToGrayscaleBitmap(ColorChannel.Alpha);
            // Blur the GrayscaleBitmap to create a believable looking shadow:            gs.ApplyGaussianBlur(9);
            // Convert the transparency mask from GrayscaleBitmap to GcBitmap,            // filling the opaque pixels with the shadow color (CadetBlue),            // also making the resulting 'shadow' slightly transparent (0.6f):            gs.ToShadowBitmap(bmp, Color.CadetBlue, 0.6f);
            // Replace the transparent background with an opaque background color:            bmp.ConvertToOpaque(Color.LightGoldenrodYellow);
            // Finally draw the original image without offset on top:            using (var g = bmp.CreateGraphics())            {                Draw(g, 0, 0);            }
            // Done            return bmp;        }
        private void Draw(GcGraphics g, float offsetX, float offsetY)        {            var baseT = Matrix3x2.CreateTranslation(offsetX, offsetY);            g.Transform = baseT;            g.DrawEllipse(new RectangleF(100, 100, 300, 200), new GCDRAW.Pen(Color.Orange, 20));            g.DrawLine(new PointF(50, 400), new PointF(500, 50), new GCDRAW.Pen(Color.RoyalBlue, 20)            {                LineCap = PenLineCap.Round            });            g.DrawString("Howl's Moving Castle",                new TextFormat                {                    Font = _font,                    FontSize = 40,                    ForeColor = Color.MistyRose,                    StrokePen = new GCDRAW.Pen(Color.DarkRed, 1)                },                new PointF(200, 150));            g.Transform =                Matrix3x2.CreateRotation((float)(Math.PI / 6)) *                (Matrix3x2.CreateTranslation(50, 250) * baseT);            g.DrawString("The quick brown fox jumps over the lazy dog.",                new TextFormat                {                    Font = _font,                    FontSize = 18,                    ForeColor = Color.CornflowerBlue                },                new PointF(0, 0));            g.DrawRectangle(new RectangleF(-15, -10, 470, 50), new GCDRAW.Pen(Color.Salmon, 1));
            g.Transform = baseT;
            // Draw a window with four colored semi-transparent panes:            var wnd = new RectangleF(520, 420, 400, 500);            var winHalf = new SizeF(wnd.Width / 2, wnd.Height / 2);            var frame = Color.Brown;            var glassTL = Color.FromArgb(unchecked((int)0x70FF4600));            var glassTR = Color.FromArgb(unchecked((int)0x70A5FF00));            var glassBL = Color.FromArgb(unchecked((int)0x70007BFF));            var glassBR = Color.FromArgb(unchecked((int)0x70FFCD00));
            g.FillRectangle(new RectangleF(wnd.Location, winHalf), glassTL);            g.FillRectangle(new RectangleF(new PointF(wnd.X + wnd.Width / 2, wnd.Y), winHalf), glassTR);            g.FillRectangle(new RectangleF(new PointF(wnd.X, wnd.Y + wnd.Height / 2), winHalf), glassBL);            g.FillRectangle(new RectangleF(new PointF(wnd.X + wnd.Width / 2, wnd.Y + wnd.Height / 2), winHalf), glassBR);
            g.DrawRectangle(wnd, new GCDRAW.Pen(frame, 30));            g.DrawLine(wnd.Left, wnd.Top + wnd.Height / 2, wnd.Right, wnd.Top + wnd.Height / 2, frame, 20);            g.DrawLine(wnd.Left + wnd.Width / 2, wnd.Top, wnd.Left + wnd.Width / 2, wnd.Bottom, frame, 20);
            g.Transform = Matrix3x2.Identity;        }    }}