Font renderer implementation.

Source/OpenTK/Fonts/DisplayListTextPrinter.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using OpenTK.OpenGL;
+
+namespace OpenTK.Fonts
+{
+    /// <summary>
+    /// Provides text printing through OpenGL 1.1 Display Lists.
+    /// </summary>
+    class DisplayListTextPrinter : ITextPrinterImplementation
+    {
+        #region IPrinter Members
+
+        public TextHandle Load(OpenTK.Math.Vector2[] vertices, ushort[] indices)
+        {
+            DisplayListTextHandle handle = new DisplayListTextHandle(GL.GenLists(1));
+
+            GL.NewList(handle.Handle, OpenTK.OpenGL.Enums.ListMode.Compile);
+            GL.Begin(OpenTK.OpenGL.Enums.BeginMode.Triangles);
+
+            foreach (ushort index in indices)
+            {
+                GL.TexCoord2(vertices[index + 1]);
+                GL.Vertex2(vertices[index]);
+            }
+
+            GL.End();
+            GL.EndList();
+
+            return handle;
+        }
+
+        public void Draw(TextHandle handle)
+        {
+            GL.CallList(handle.Handle);
+        }
+
+        #endregion
+    }
+
+    public class DisplayListTextHandle : TextHandle
+    {
+        public DisplayListTextHandle(int handle) : base(handle) { }
+    }
+}

Source/OpenTK/Fonts/IPrinterImplementation.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using OpenTK.Math;
+
+namespace OpenTK.Fonts
+{
+    /// <summary>
+    /// Defines the interface for TextPrinter implementations.
+    /// </summary>
+    interface ITextPrinterImplementation
+    {
+        TextHandle Load(Vector2[] vertices, ushort[] indices);
+        void Draw(TextHandle handle);
+    }
+}

Source/OpenTK/Fonts/TextHandle.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace OpenTK.Fonts
+{
+    public class TextHandle
+    {
+        internal TextHandle(int handle)
+        {
+            Handle = handle;
+        }
+
+        public readonly int Handle;
+        internal TextureFont font;
+
+        public override string ToString()
+        {
+            return String.Format("TextHandle: {0}", Handle);
+        }
+    }
+}

Source/OpenTK/Fonts/TextPrinter.cs

@@ -9,11 +9,11 @@ using System.Collections.Generic;
 using System.Text;
 using System.Drawing;
 using System.Text.RegularExpressions;
+using System.Runtime.InteropServices;
 
 using OpenTK.Math;
 using OpenTK.OpenGL;
 using OpenTK.OpenGL.Enums;
-using System.Runtime.InteropServices;
 
 
 namespace OpenTK.Fonts
@@ -27,7 +27,7 @@ namespace OpenTK.Fonts
         //static char[] split_chars = new char[] { ' ', '\n', '\t', ',', '.', '/', '?', '!', ';', '\\', '-', '+', '*', '=' };
         static bool use_vbo, use_arb_vbo, use_display_list;
         static bool functionality_checked = false;
-        static IPrinter printer;
+        static ITextPrinterImplementation printer;
 
         #region --- Constructor ---
 
@@ -43,11 +43,12 @@ namespace OpenTK.Fonts
         /// </summary>
         static void CheckNeededFunctionality()
         {
-            printer =
+            printer = new DisplayListTextPrinter();
-                GL.SupportsExtension("VERSION_1_5") ? new VboPrinter() :
+                /*
+                GL.SupportsExtension("VERSION_1_5") ? new VboTextPrinter() :
                 GL.SupportsExtension("ARB_vertex_buffer_object") ? null :
                 GL.SupportsExtension("VERSION_1_1") ? null : null;
-            
+                */
             if (printer == null)
                 throw new NotSupportedException("DefaultLayoutProvider requires at least OpenGL 1.1 support.");
             
@@ -79,8 +80,8 @@ namespace OpenTK.Fonts
             if (text == null)
                 throw new ArgumentNullException("Parameter cannot be null.", "text");
 
-            if (text.Length > 4096)
+            if (text.Length > 8192)
-                throw new ArgumentOutOfRangeException("text", text.Length, "Text length must be between 1 and 4096 characters");
+                throw new ArgumentOutOfRangeException("text", text.Length, "Text length must be between 1 and 8192 characters");
 
             Vector2[] vertices = new Vector2[8 * text.Length];  // Interleaved, vertex, texcoord, vertex, etc...
             ushort[] indices = new ushort[6 * text.Length];
@@ -90,6 +91,8 @@ namespace OpenTK.Fonts
             float char_width, char_height, measured_width, measured_height;
             int texture;
 
+            font.LoadGlyphs(text);
+
             // Every character comprises of 4 vertices, forming two triangles. We generate an index array which
             // indexes vertices in a triangle-strip fashion. To create a single strip for the whole string, we
             // need to add a degenerate triangle (0 height) to connect the last vertex of the previous line with
@@ -168,7 +171,8 @@ namespace OpenTK.Fonts
             GL.Enable(EnableCap.Blend);
             GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
 
-            GL.Enable(EnableCap.Blend);
+            //GL.Disable(EnableCap.Texture2d);
+
             GL.BindTexture(TextureTarget.Texture2d, handle.font.Texture);
             
             printer.Draw(handle);
@@ -179,78 +183,4 @@ namespace OpenTK.Fonts
 
         #endregion
     }
-
-    public class TextHandle
-    {
-        internal TextHandle(int handle)
-        {
-            Handle = handle;
-        }
-
-        public readonly int Handle;
-        internal TextureFont font;
-    }
-
-    class VboTextHandle : TextHandle
-    {
-        public VboTextHandle(int handle) : base(handle) { }
-
-        internal int vbo_id;    // vertex buffer object id.
-        internal int ebo_id;    // index buffer object id.
-        internal int element_count;     // Number of elements in the ebo.
-    }
-
-    interface IPrinter
-    {
-        TextHandle Load(Vector2[] vertices, ushort[] indices);
-        void Draw(TextHandle handle);
-    }
-
-    class VboPrinter : IPrinter
-    {
-        static int allocated_handles;
-        static int vector2_size = Marshal.SizeOf(new Vector2());
-
-        #region --- IPrinter Members ---
-
-        public TextHandle Load(Vector2[] vertices, ushort[] indices)
-        {
-            VboTextHandle handle = new VboTextHandle(++allocated_handles);
-            GL.GenBuffers(1, out handle.vbo_id);
-            GL.GenBuffers(1, out handle.ebo_id);
-
-            GL.BindBuffer(Version15.ArrayBuffer, handle.vbo_id);
-            GL.BufferData(Version15.ArrayBuffer, (IntPtr)(vertices.Length * vector2_size), vertices,
-                          Version15.StaticDraw);
-
-            GL.BindBuffer(Version15.ElementArrayBuffer, handle.ebo_id);
-            GL.BufferData(Version15.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(ushort)), indices,
-                          Version15.StaticDraw);
-            handle.element_count = indices.Length;
-
-            return handle;
-        }
-
-        public void Draw(TextHandle handle)
-        {
-            VboTextHandle vbo = (VboTextHandle)handle;
-
-            GL.PushClientAttrib(ClientAttribMask.ClientVertexArrayBit);
-
-            GL.BindBuffer(Version15.StaticDraw, vbo.vbo_id);
-            GL.BindBuffer(Version15.ElementArrayBuffer, vbo.ebo_id);
-
-            GL.EnableClientState(EnableCap.VertexArray);
-            GL.EnableClientState(EnableCap.TextureCoordArray);
-
-            GL.TexCoordPointer(2, TexCoordPointerType.Float, vector2_size, (IntPtr)vector2_size);
-            GL.VertexPointer(2, VertexPointerType.Float, vector2_size, IntPtr.Zero);
-
-            GL.DrawElements(BeginMode.Triangles, vbo.element_count, All.UnsignedShort, IntPtr.Zero);
-
-            GL.PopClientAttrib();
-        }
-
-        #endregion
-    }
 }

Source/OpenTK/Fonts/TextureFont.cs

@@ -15,15 +15,17 @@ using OpenTK.OpenGL;
 using OpenTK.OpenGL.Enums;
 using System.Drawing.Imaging;
 using OpenTK.Platform;
+using System.Drawing;
 
 namespace OpenTK.Fonts
 {
     public class TextureFont : IFont
     {
-        System.Drawing.Font font;
+        Font font;
         Dictionary<char, Box2> loaded_glyphs = new Dictionary<char, Box2>(64);
 
-        System.Drawing.Graphics gfx = System.Drawing.Graphics.FromImage(new System.Drawing.Bitmap(1, 1));
+        Bitmap bmp;
+        Graphics gfx;
         static int texture;
         static TexturePacker<Glyph> pack;
         static int texture_width, texture_height;
@@ -41,6 +43,9 @@ namespace OpenTK.Fonts
                 throw new ArgumentNullException("font", "Argument to TextureFont constructor cannot be null.");
 
             this.font = font;
+
+            bmp = new Bitmap(font.Height * 2, font.Height * 2);
+            gfx = Graphics.FromImage(bmp);
         }
 
         #endregion
@@ -94,13 +99,28 @@ namespace OpenTK.Fonts
 
         #endregion
 
+        #region public void LoadGlyph(char glyph)
+
+        /// <summary>
+        /// Prepares the specified glyph for rendering.
+        /// </summary>
+        /// <param name="glyphs">The glyph to prepare for rendering.</param>
+        public void LoadGlyph(char glyph)
+        {
+            Box2 rect = new Box2();
+            if (!loaded_glyphs.ContainsKey(glyph))
+                LoadGlyph(glyph, out rect);
+        }
+
+        #endregion
+
         #region private void LoadGlyph(char c, out Box2 rectangle)
 
         /// <summary>
         /// Adds a glyph to the texture packer.
         /// </summary>
         /// <param name="c">The character of the glyph.</param>
-        /// <param name="rectangle">A RectangleF that will hold the data for this glyph.</param>
+        /// <param name="rectangle">An OpenTK.Math.Box2 that will hold the data for this glyph.</param>
         private void LoadGlyph(char c, out Box2 rectangle)
         {
             if (pack == null)
@@ -109,25 +129,48 @@ namespace OpenTK.Fonts
             Glyph g = new Glyph(c, font);
             System.Drawing.Rectangle rect = pack.Add(g);
 
-            using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(
+            //using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(rect.Width, rect.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
-                rect.Width, rect.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
+            //using (System.Drawing.Graphics gfx = System.Drawing.Graphics.FromImage(bmp))
-            using (System.Drawing.Graphics gfx = System.Drawing.Graphics.FromImage(bmp))
             {
-                // Upload texture data.
                 GL.BindTexture(TextureTarget.Texture2d, texture);
 
-                //gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;
+                // Set font rendering mode. Smal sizes look blurry without gridfitting, so turn
-                //gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
+                // that on. Increasing contrast also seems to help.
-                gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
+                if (font.Size <= 18.0f)
-                gfx.TextContrast = 0;
+                {
+                    gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
+                    gfx.TextContrast = 1;
+                }
+                else
+                {
+                    gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
+                    gfx.TextContrast = 0;
+                }
+                
                 gfx.Clear(System.Drawing.Color.Transparent);
                 gfx.DrawString(g.Character.ToString(), g.Font, System.Drawing.Brushes.White, 0.0f, 0.0f);
-
+                /*
                 BitmapData bmp_data = bmp.LockBits(new System.Drawing.Rectangle(0, 0, rect.Width, rect.Height), ImageLockMode.ReadOnly,
                     System.Drawing.Imaging.PixelFormat.Format32bppArgb);
                 GL.TexSubImage2D(TextureTarget.Texture2d, 0, rect.Left, rect.Top, rect.Width, rect.Height,
                     OpenTK.OpenGL.Enums.PixelFormat.Rgba, PixelType.UnsignedByte, bmp_data.Scan0);
                 bmp.UnlockBits(bmp_data);
+                */
+
+                int[] data = new int[rect.Width * rect.Height];
+                for (int y = 0; y < rect.Height; y++)
+                {
+                    for (int x = 0; x < rect.Width; x++)
+                    {
+                        data[y * rect.Width + x] = bmp.GetPixel(x, y).ToArgb();
+                    }
+                }
+                unsafe
+                {
+                    fixed (int* ptr = data)
+                        GL.TexSubImage2D(TextureTarget.Texture2d, 0, rect.Left, rect.Top, rect.Width, rect.Height,
+                        OpenTK.OpenGL.Enums.PixelFormat.Rgba, PixelType.UnsignedByte, (IntPtr)ptr);
+                }
 
                 rectangle = new Box2(
                     rect.Left / (float)texture_width,
@@ -180,6 +223,18 @@ namespace OpenTK.Fonts
 
         #endregion
 
+        #region public float Width
+
+        /// <summary>
+        /// Gets a float indicating the default line spacing of this font.
+        /// </summary>
+        public float Width
+        {
+            get { return font.SizeInPoints; }
+        }
+
+        #endregion
+
         #region internal int Texture
 
         /// <summary>

Source/OpenTK/Fonts/VboTextPrinter.cs

@@ -0,0 +1,99 @@
+#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.Runtime.InteropServices;
+
+using OpenTK.OpenGL;
+using OpenTK.Math;
+using OpenTK.OpenGL.Enums;
+
+namespace OpenTK.Fonts
+{
+    /// <summary>
+    /// Provides text printing through OpenGL 1.5 vertex buffer objects.
+    /// </summary>
+    class VboTextPrinter : ITextPrinterImplementation
+    {
+        static int allocated_handles;
+        static int vector2_size = Marshal.SizeOf(new Vector2());
+
+        #region --- IPrinter Members ---
+
+        public TextHandle Load(Vector2[] vertices, ushort[] indices)
+        {
+            VboTextHandle handle = new VboTextHandle(++allocated_handles);
+
+            GL.GenBuffers(1, out handle.vbo_id);
+            GL.BindBuffer(Version15.ArrayBuffer, handle.vbo_id);
+            GL.BufferData(Version15.ArrayBuffer, (IntPtr)(vertices.Length * vector2_size), vertices,
+                          Version15.StaticDraw);
+            GL.BindBuffer(Version15.ArrayBuffer, 0);
+
+            GL.GenBuffers(1, out handle.ebo_id);
+            GL.BindBuffer(Version15.ElementArrayBuffer, handle.ebo_id);
+            GL.BufferData(Version15.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(ushort)), indices,
+                          Version15.StaticDraw);
+            GL.BindBuffer(Version15.ElementArrayBuffer, 0);
+
+            handle.element_count = indices.Length;
+            return handle;
+        }
+
+        public void Draw(TextHandle handle)
+        {
+            VboTextHandle vbo = (VboTextHandle)handle;
+
+            //GL.PushClientAttrib(ClientAttribMask.ClientVertexArrayBit);
+
+            //GL.EnableClientState(EnableCap.TextureCoordArray);
+            GL.EnableClientState(EnableCap.VertexArray);
+
+            GL.BindBuffer(Version15.StaticDraw, vbo.vbo_id);
+            GL.BindBuffer(Version15.ElementArrayBuffer, vbo.ebo_id);
+
+            GL.TexCoordPointer(2, TexCoordPointerType.Float, vector2_size, (IntPtr)vector2_size);
+            GL.VertexPointer(2, VertexPointerType.Float, vector2_size, IntPtr.Zero);
+
+            GL.DrawElements(BeginMode.Triangles, vbo.element_count, All.UnsignedShort, IntPtr.Zero);
+            //GL.DrawArrays(BeginMode.LineLoop, 0, vbo.element_count);
+
+            GL.BindBuffer(Version15.ArrayBuffer, 0);
+            GL.BindBuffer(Version15.ElementArrayBuffer, 0);
+
+            GL.DisableClientState(EnableCap.VertexArray);
+            //GL.DisableClientState(EnableCap.TextureCoordArray);
+
+            //GL.PopClientAttrib();
+        }
+
+        #endregion
+    }
+
+    #region class VboTextHandle : TextHandle
+
+    /// <summary>
+    /// Contains the necessary information to print text through the VboTextPrinter implementation.
+    /// </summary>
+    class VboTextHandle : TextHandle
+    {
+        public VboTextHandle(int handle) : base(handle) { }
+
+        internal int vbo_id;    // vertex buffer object id.
+        internal int ebo_id;    // index buffer object id.
+        internal int element_count;     // Number of elements in the ebo.
+
+        public override string ToString()
+        {
+            return String.Format("TextHandle (vbo): {0} ({1} element(s), vbo id: {2}, ebo id: {3}",
+                Handle, element_count / 6, vbo_id, ebo_id);
+        }
+    }
+
+    #endregion
+}