Graphics transformations

PDF TIFF SVG JPG C# VB
Transforms.cs 
  1. //
  2. // This code is part of Document Solutions for PDF demos.
  3. // Copyright (c) MESCIUS inc. All rights reserved.
  4. //
  5. using System;
  6. using System.IO;
  7. using System.Drawing;
  8. using System.Numerics;
  9. using GrapeCity.Documents.Drawing;
  10. using GrapeCity.Documents.Pdf;
  11. using GrapeCity.Documents.Text;
  12.  
  13. namespace DsPdfWeb.Demos.Basics
  14. {
  15.     // Shows how to use graphics transformations (GcPdfGraphics.Transform property).
  16.     public class Transforms
  17.     {
  18.         // Helper method drawing a filled box with text:
  19.         private static void DrawBox(string text, GcGraphics g, RectangleF box)
  20.         {
  21.             g.FillRectangle(box, Color.FromArgb(80, 0, 184, 204));
  22.             g.DrawRectangle(box, Color.FromArgb(0, 193, 213), 1);
  23.             box.Inflate(-6, -6);
  24.             g.DrawString(text, new TextFormat() { Font = StandardFonts.Times, FontSize = 14, }, box);
  25.         }
  26.  
  27.         public int CreatePDF(Stream stream)
  28.         {
  29.             const string baseTxt = "Text drawn at (0,36) in a 4\"x2\" box";
  30.             var doc = new GcPdfDocument();
  31.             var page = doc.NewPage();
  32.             var g = page.Graphics;
  33.             var box = new RectangleF(0, 36, 72 * 4, 72 * 2);
  34.             // #1:
  35.             DrawBox($"Box 1: {baseTxt}, no transformations.", g, box);
  36.             //
  37.             var translate0 = Matrix3x2.CreateTranslation(72 * 1, 72 * 4);
  38.             var scale0 = Matrix3x2.CreateScale(0.5f);
  39.  
  40.             // Transforms are applied in order from last to first.
  41.  
  42.             // #2:
  43.             g.Transform =
  44.                 scale0 *
  45.                 translate0;
  46.             DrawBox($"Box 2: {baseTxt}, translated by (1\",4\") and scaled by 0.5.", g, box);
  47.             // #3:
  48.             g.Transform =
  49.                 translate0 *
  50.                 scale0;
  51.             DrawBox($"Box 3: {baseTxt}, scaled by 0.5 and translated by (1\",4\").", g, box);
  52.             //
  53.             var translate1 = Matrix3x2.CreateTranslation(72 * 3, 72 * 5);
  54.             var scale1 = Matrix3x2.CreateScale(0.7f);
  55.             var rotate0 = Matrix3x2.CreateRotation((float)(-70 * Math.PI) / 180f); // 70 degrees CCW
  56.             // #4:
  57.             g.Transform =
  58.                 rotate0 *
  59.                 translate1 *
  60.                 scale1;
  61.             DrawBox($"Box 4: {baseTxt}, scaled by 0.7, translated by (3\",5\"), and rotated 70 degrees counterclockwise.", g, box);
  62.             // #5:
  63.             g.Transform =
  64.                 Matrix3x2.CreateTranslation(36, 72) *
  65.                 g.Transform;
  66.             DrawBox($"Box 5: {baseTxt}, applied current transform (Box 4), and translated by (1/2\",1\").", g, box);
  67.             // #6:
  68.             g.Transform =
  69.                 // rotate0 *
  70.                 Matrix3x2.CreateSkew((float)(-45 * Math.PI) / 180f, (float)(20 * Math.PI) / 180f) *
  71.                 Matrix3x2.CreateTranslation(72 * 3, 72 * 7);
  72.             DrawBox($"Box 6: {baseTxt}, translated by (3\",7\"), and skewed -45 degrees on axis X and 20 degrees on axis Y.", g, box);
  73.             // #7:
  74.             g.Transform =
  75.                 Matrix3x2.CreateRotation((float)Math.PI) *
  76.                 Matrix3x2.CreateTranslation(page.Size.Width - 72, page.Size.Height - 72);
  77.             DrawBox($"Box 7: {baseTxt}, translated by (7.5\",10\"), and rotated by 180 degrees.", g, box);
  78.             // We can remove any transformations on a graphics like so:
  79.             g.Transform = Matrix3x2.Identity;
  80.  
  81.             // Done:
  82.             doc.Save(stream);
  83.             return doc.Pages.Count;
  84.         }
  85.     }
  86. }
  87.