//// 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 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 sample demonstrates the effects of different blend modes    // when drawing on a GcGraphics. Note that the current blend mode    // set on an instance of GcGraphics (including GcBitmapGraphics)    // affects not only images but all drawing operations.    // See also BlendImages_0 and BlendingModes samples.    public class BlendText    {        public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] _ = null)        {            var ispectr = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "spectrum-500x500.png"));            const int margin = 36;            const int NCOLS = 4;            var w = (int)((pixelSize.Width - margin * 2) / NCOLS);            var h = w / 2;            int row = 0, col = 0;            float bottomy = 0;
            var bmp = new GcBitmap(pixelSize.Width, pixelSize.Height, opaque, dpi, dpi);            using (var g = bmp.CreateGraphics(Color.White))            {                // Text layout for captions:                var tl = g.CreateTextLayout();                tl.DefaultFormat.Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeMonoBold.ttf"));                tl.DefaultFormat.FontSize = 22;                tl.ParagraphAlignment = ParagraphAlignment.Center;                tl.TextAlignment = TextAlignment.Center;                tl.MaxWidth = w;                tl.MaxHeight = h;                tl.MarginTop = (h - h / 1.4f) / 2;                tl.DefaultFormat.ForeColor = Color.Black;                var tfWhite = new TextFormat(tl.DefaultFormat) { ForeColor = Color.White };
                // Render all blend modes in a grid:                var modes = Enum.GetValues(typeof(BlendMode));                foreach (var mode in modes)                {                    var blendMode = (BlendMode)mode;                    if (!g.IsBlendModeSupported(blendMode))                        continue;
                    int x = margin + w * col;                    int y = margin + h * row;                    var r = new RectangleF(x, y, w, h);
                    // Draw spectrum image normally:                    g.BlendMode = BlendMode.Normal;                    g.DrawImage(ispectr, r, null, ImageAlign.StretchImage);                    // Draw blend mode name using the current blend mode:                    tl.Clear();                    tl.AppendLine($"B: {blendMode}");                    tl.Append($"W: {blendMode}", tfWhite);                    tl.PerformLayout(true);                    var rc = tl.ContentRectangle;                    rc.Offset(x, y);                    rc.Inflate(4, 2);                    // Current blend mode:                    g.BlendMode = blendMode;                    g.DrawTextLayout(tl, new PointF(x, y));                    // Draw spectrum image again using BlendMode.Difference                    // to produce (mostly) colorful text on black background:                    g.BlendMode = BlendMode.Difference;                    g.DrawImage(ispectr, r, null, ImageAlign.StretchImage);                    // Draw a rectangle to mark the current area:                    g.BlendMode = BlendMode.Normal;                    g.DrawRectangle(r, Color.Gray);                    bottomy = r.Bottom;                    if (++col == NCOLS)                    {                        col = 0;                        ++row;                    }                }                // For reference, draw the backdrop:                tl.Clear();                tl.MarginAll = 0;                tl.MaxWidth = bmp.PixelWidth;                tl.MaxHeight = null;                tl.DefaultFormat.FontSize = 14;                tl.TextAlignment = TextAlignment.Leading;                tl.ParagraphAlignment = ParagraphAlignment.Near;                tl.Append("The spectrum image used as the backdrop for the texts above:");                g.DrawTextLayout(tl, new PointF(margin, bottomy + margin));                g.DrawImage(ispectr, new RectangleF(margin, bottomy + margin + tl.ContentHeight + 24, w, w), null, ImageAlign.StretchImage);            }            return bmp;        }    }}