Added IFont and DefaultLayoutProvider classes.

Source/OpenTK/Fonts/DefaultLayoutProvider.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Drawing;
+using System.Text.RegularExpressions;
+
+using OpenTK.Math;
+using OpenTK.OpenGL;
+
+
+namespace OpenTK.Fonts
+{
+    public class DefaultLayoutProvider : ILayoutProvider
+    {
+        static Regex break_point = new Regex("[ .,/*-+?\\!=]", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+        static char[] split_chars = new char[] { ' ', ',', '.', '/', '?', '!', ';', '\\', '-', '+', '*', '=' };
+
+        #region --- ILayoutProvider Members ---
+
+        public void PerformLayout(string text, IFont font, RectangleF layoutRect, StringAlignment alignment, bool rightToLeft)
+        {
+            Vector2[] vertices = new Vector2[2 * text.Length + 4];
+            float x_pos, y_pos;
+            int i = 0, count, last_break_point = 0;
+            
+            if (alignment == StringAlignment.Near && !rightToLeft || alignment == StringAlignment.Far && rightToLeft)
+            {
+                x_pos = vertices[0].X = layoutRect.Left;
+                y_pos = vertices[0].Y = layoutRect.Top;
+                vertices[1].X = x_pos;
+                vertices[1].Y = y_pos - font.Height;
+
+                count = 2;
+                foreach (char c in text)
+                {
+                    // TODO: This code breaks for small widths or for words that do not fit in one width.
+                    if (Char.IsSeparator(c))
+                        last_break_point = i;
+
+                    x_pos += font.MeasureString(text.Substring(i, 1)).Width;
+                    if (x_pos > layoutRect.Width)
+                    {
+                        // Move the last word to the next line. If there is not enough vertical space
+                        // for a new line, finish layout.
+
+                        y_pos += font.Height;
+                        if (y_pos > layoutRect.Bottom)
+                            break;
+                        x_pos = layoutRect.Left;
+
+                        for (int j = last_break_point; j < i; j++)
+                        {
+                            int current_vertex = 2 * (j + 1);
+                            vertices[current_vertex].X = x_pos;
+                            vertices[current_vertex].Y += font.Height;
+                            current_vertex++;
+                            vertices[current_vertex].X = x_pos;
+                            vertices[current_vertex].Y += font.Height;
+
+                            x_pos += font.MeasureString(text.Substring(j, 1)).Width;
+                        }
+
+                        x_pos += font.MeasureString(text.Substring(i, 1)).Width;
+                    }
+                    vertices[count].X = x_pos;
+                    vertices[count].Y = y_pos;
+                    ++count;
+                    vertices[count].X = x_pos;
+                    vertices[count].Y = y_pos - font.Height;
+                    ++count;
+
+                    ++i;
+                }
+            }
+            else if (alignment != StringAlignment.Center)
+            {
+                throw new NotImplementedException("This feature is not yet implemented. Sorry for the inconvenience.");
+            }
+            else
+            {
+                throw new NotImplementedException("This feature is not yet implemented. Sorry for the inconvenience.");
+            }
+
+            int buf;
+            GL.GenBuffers(1, out buf);
+            
+        }
+
+        #endregion
+    }
+}

Source/OpenTK/Fonts/IFont.cs

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+#region --- License ---
+/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
+ * See license.txt for license info
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Drawing;
+
+namespace OpenTK.Fonts
+{
+    public interface IFont : IDisposable
+    {
+        void LoadGlyphs(string glyphs);
+        RectangleF FindRectangle(char c);
+        float Height { get; }
+        SizeF MeasureString(string str);
+    }
+}