// // This code is part of Document Solutions for PDF demos. // Copyright (c) MESCIUS inc. All rights reserved. // using System; using System.IO; using System.Drawing; using System.Linq; using GrapeCity.Documents.Pdf; using GrapeCity.Documents.Text; using GrapeCity.Documents.Drawing; using GrapeCity.Documents.Imaging; using GCTEXT = GrapeCity.Documents.Text; using GCDRAW = GrapeCity.Documents.Drawing; namespace DsPdfWeb.Demos { // This sample demonstrates the effects of different blend modes // when drawing on a GcPdfGraphics. Note that the current blend mode // set on an instance of GcGraphics (including GcPdfGraphics) // affects not only images but all drawing operations. // In this sample it is demonstrated by rendering the blend mode // names on the second page. public class AllBlendModes { public int CreatePDF(Stream stream) { var doc = new GcPdfDocument(); var page = doc.NewPage(); var g = page.Graphics; var iorchid = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "orchid.jpg")); var ispectr = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "spectrum-pastel-500x500.png")); const int margin = 36; const int NCOLS = 4; var w = (int)((page.Size.Width - margin * 2) / NCOLS); var h = (int)((iorchid.Height * w) / iorchid.Width); // Text layout for captions: var tl = g.CreateTextLayout(); tl.DefaultFormat.Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "NotoSansMono-Regular.ttf")); tl.DefaultFormat.FontSize = 12; tl.ParagraphAlignment = ParagraphAlignment.Center; tl.TextAlignment = TextAlignment.Center; tl.MaxWidth = w; tl.MaxHeight = h; tl.MarginTop = h - g.MeasureString("QWERTY", tl.DefaultFormat).Height * 1.4f; int row = 0, col, dy; // Render all blending modes in a grid: var modes = Enum.GetValues(typeof(BlendMode)); for (int i = 0; i < 2; ++i) { row = col = 0; GCDRAW.Image iback, ifore; if (i == 0) { iback = ispectr; ifore = iorchid; var trc1 = Common.Util.AddNote( "Below are tiles drawn by composing two images (a spectrum and an orchid) using the " + "different blend modes supported by DsPdf. " + "First the spectrum image is drawn normally, then it is overlaid by the orchid image " + "drawn in a supported blend mode. The blend mode name is shown below each tile." + "\n" + "Tiles on the second page are composed of the same images but drawn in reverse order: " + "the orchid is drawn normally, the spectrum is blended with it using the different modes." + "\n" + "Note that the current blend mode affects not only images but any drawing on a GcGraphics. " + "The blend mode names on the 2nd page illustrate this.", page); dy = (int)trc1.Bottom; } else // i == 1 { iback = iorchid; ifore = ispectr; page = doc.Pages.Add(); g = page.Graphics; dy = 0; } foreach (var mode in modes) { var blendMode = (BlendMode)mode; if (!g.IsBlendModeSupported(blendMode)) continue; int x = margin + w * col; int y = margin + h * row + dy; var r = new RectangleF(x, y, w, h); g.BlendMode = BlendMode.Normal; g.DrawImage(iback, r, null, ImageAlign.StretchImage); g.BlendMode = blendMode; g.DrawImage(ifore, r, null, ImageAlign.StretchImage); g.BlendMode = BlendMode.Normal; // Caption: tl.Clear(); tl.Append(blendMode.ToString()); tl.PerformLayout(true); var rc = tl.ContentRectangle; rc.Offset(x, y); rc.Inflate(4, 2); g.FillRectangle(rc, Color.White); g.DrawTextLayout(tl, new PointF(x, y)); nextRowCol(); } } // Text blends: page = doc.Pages[1]; g = page.Graphics; var trc = Common.Util.AddNote( "Below are supported blend mode names rendered into rectangles using the corresponding blend mode. " + "Each rectangle is first filled by the spectrum image using BlendMode.Normal, " + "then black and white texts are drawn using the current blend mode, " + "finally the same spectrum image is drawn using BlendMode.Difference to black out the background. " + "Names prefixed with 'B:' are drawn in black, " + "while names prefixed with 'W:' are drawn in white. " + "Most combinations yield rather colorful results, but for some the results are invisible.", page, new RectangleF(margin, margin + h * row + 12, page.Bounds.Width - margin * 2, 0)); var yoff = (int)trc.Bottom + 12; tl.DefaultFormat.FontBold = true; tl.DefaultFormat.FontSize = 16; h = (int)(g.MeasureString("QWERTY", tl.DefaultFormat).Height * 1.4f) * 2; 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 }; row = col = 0; foreach (var mode in modes) { var blendMode = (BlendMode)mode; if (!g.IsBlendModeSupported(blendMode)) continue; int x = margin + w * col; int y = yoff + 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); nextRowCol(); } // Done: doc.Save(stream); return doc.Pages.Count; // void nextRowCol() { if (++col == NCOLS) { col = 0; ++row; } } } } }