Font renderer implementation.

This commit is contained in:
the_fiddler 2007-11-06 20:59:15 +00:00
parent 336e6210c8
commit 4a5cd43003
6 changed files with 264 additions and 94 deletions

View file

@ -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) { }
}
}

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@ -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);
}
}

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@ -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);
}
}
}

View file

@ -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 =
GL.SupportsExtension("VERSION_1_5") ? new VboPrinter() :
printer = new DisplayListTextPrinter();
/*
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)
throw new ArgumentOutOfRangeException("text", text.Length, "Text length must be between 1 and 4096 characters");
if (text.Length > 8192)
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
}
}

View file

@ -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(
rect.Width, rect.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
using (System.Drawing.Graphics gfx = System.Drawing.Graphics.FromImage(bmp))
//using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(rect.Width, rect.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
//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;
//gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
gfx.TextContrast = 0;
// Set font rendering mode. Smal sizes look blurry without gridfitting, so turn
// that on. Increasing contrast also seems to help.
if (font.Size <= 18.0f)
{
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>

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@ -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
}