Opentk/Source/OpenTK/Fonts/TextureFont.cs

327 lines
11 KiB
C#

#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;
using System.Drawing.Text;
using OpenTK.Math;
using OpenTK.OpenGL;
using OpenTK.OpenGL.Enums;
using System.Drawing.Imaging;
using OpenTK.Platform;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace OpenTK.Fonts
{
public class TextureFont : IFont
{
Font font;
Dictionary<char, Box2> loaded_glyphs = new Dictionary<char, Box2>(64);
Bitmap bmp;
Graphics gfx;
// TODO: We need to be able to use multiple font sheets.
static int texture;
static TexturePacker<Glyph> pack;
static int texture_width, texture_height;
int[] data = new int[256]; // Used to upload glyph data to the OpenGL texture.
object upload_lock = new object();
#region --- Constructor ---
/// <summary>
/// Constructs a new TextureFont object, using the specified System.Drawing.Font.
/// </summary>
/// <param name="font">The System.Drawing.Font to use.</param>
public TextureFont(Font font)
{
if (font == null)
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);
// Adjust font rendering mode. Small sizes look blurry without gridfitting, so turn
// that on. Increasing contrast also seems to help.
if (font.Size <= 18.0f)
{
gfx.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
gfx.TextContrast = 1;
}
else
{
gfx.TextRenderingHint = TextRenderingHint.AntiAlias;
gfx.TextContrast = 0;
}
}
#endregion
#region private void PrepareTexturePacker()
/// <summary>
/// Calculates the optimal size for the font texture and TexturePacker, and creates both.
/// </summary>
private void PrepareTexturePacker()
{
// Calculate the size of the texture packer. We want a power-of-two size
// that is less than 1024 (supported in Geforce256-era cards), but large
// enough to hold at least 256 (16*16) font glyphs.
// TODO: Find the actual card limits, maybe?
int size = (int)(font.Size * 16);
size = (int)System.Math.Pow(2.0, System.Math.Ceiling(System.Math.Log((double)size, 2.0)));
if (size > 1024)
size = 1024;
texture_width = size;
texture_height = size;
pack = new TexturePacker<Glyph>(texture_width, texture_height);
GL.GenTextures(1, out texture);
GL.BindTexture(TextureTarget.Texture2d, texture);
GL.TexParameter(TextureTarget.Texture2d, TextureParameterName.TextureMinFilter, (int)All.Linear);
GL.TexParameter(TextureTarget.Texture2d, TextureParameterName.TextureMagFilter, (int)All.Linear);
GL.TexImage2D(TextureTarget.Texture2d, 0, PixelInternalFormat.Alpha, texture_width, texture_height, 0,
OpenTK.OpenGL.Enums.PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero);
}
#endregion
#region public void LoadGlyphs(string glyphs)
/// <summary>
/// Prepares the specified glyphs for rendering.
/// </summary>
/// <param name="glyphs">The glyphs to prepare for rendering.</param>
public void LoadGlyphs(string glyphs)
{
Box2 rect = new Box2();
foreach (char c in glyphs)
{
if (!loaded_glyphs.ContainsKey(c))
LoadGlyph(c, out rect);
}
}
#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">An OpenTK.Math.Box2 that will hold the data for this glyph.</param>
private void LoadGlyph(char c, out Box2 rectangle)
{
if (pack == null)
PrepareTexturePacker();
Glyph g = new Glyph(c, font);
Rectangle rect = new Rectangle();
try
{
pack.Add(g, out rect);
}
catch (InvalidOperationException expt)
{
// TODO: The TexturePacker is full, create a new font sheet.
Trace.WriteLine(expt);
throw;
}
GL.BindTexture(TextureTarget.Texture2d, texture);
gfx.Clear(System.Drawing.Color.Transparent);
gfx.DrawString(g.Character.ToString(), g.Font, System.Drawing.Brushes.White, 0.0f, 0.0f);
//BitmapData bitmap_data = bitmap.LockBits(new 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, bitmap_data.Scan0);
//bitmap.UnlockBits(bitmap_data);
BitmapData bitmap_data = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly,
System.Drawing.Imaging.PixelFormat.Format32bppArgb);
int needed_size = rect.Width * rect.Height;
if (data.Length < needed_size)
Array.Resize<int>(ref data, needed_size);
Array.Clear(data, 0, needed_size);
unsafe
{
int* bitmap_data_ptr = (int*)bitmap_data.Scan0;
for (int y = 0; y < rect.Height; y++)
{
for (int x = 0; x < rect.Width; x++)
{
data[y * rect.Width + x] = *(bitmap_data_ptr + y * bmp.Width + x);
}
}
fixed (int* data_ptr = data)
GL.TexSubImage2D(TextureTarget.Texture2d, 0, rect.Left, rect.Top, rect.Width, rect.Height,
OpenTK.OpenGL.Enums.PixelFormat.Rgba, PixelType.UnsignedByte, (IntPtr)data_ptr);
}
bmp.UnlockBits(bitmap_data);
rectangle = new Box2(
rect.Left / (float)texture_width,
rect.Top / (float)texture_height,
rect.Right / (float)texture_width,
rect.Bottom / (float)texture_height);
loaded_glyphs.Add(g.Character, rectangle);
}
#endregion
#region public bool GlyphData(char glyph, out float width, out float height, out Box2 textureRectangle, out int texture)
/// <summary>
/// Returns the characteristics of a loaded glyph.
/// </summary>
/// <param name="glyph">The character corresponding to this glyph.</param>
/// <param name="width">The width of this glyph.</param>
/// <param name="height">The height of this glyph (line spacing).</param>
/// <param name="textureRectangle">The bounding box of the texture data of this glyph.</param>
/// <param name="texture">The handle to the texture that contains this glyph.</param>
/// <returns>True if the glyph has been loaded, false otherwise.</returns>
/// <seealso cref="LoadGlyphs"/>
public bool GlyphData(char glyph, out float width, out float height, out Box2 textureRectangle, out int texture)
{
if (loaded_glyphs.TryGetValue(glyph, out textureRectangle))
{
width = textureRectangle.Width * texture_width;
height = textureRectangle.Height * texture_height;
texture = TextureFont.texture;
return true;
}
width = height = texture = 0;
return false;
}
#endregion
#region public float Height
/// <summary>
/// Gets a float indicating the default line spacing of this font.
/// </summary>
public float Height
{
get { return font.Height; }
}
#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>
/// Gets the handle to the texture were this font resides.
/// </summary>
internal int Texture
{
get { return TextureFont.texture; }
}
#endregion
#region public void MeasureString(string str, out float width, out float height)
/// <summary>
/// Measures the width of the specified string.
/// </summary>
/// <param name="str">The string to measure.</param>
/// <param name="width">The measured width.</param>
/// <param name="height">The measured height.</param>
public void MeasureString(string str, out float width, out float height)
{
System.Drawing.SizeF size = gfx.MeasureString(str, font, 16384, System.Drawing.StringFormat.GenericTypographic);
if (size.Width == 0)
width = font.SizeInPoints * 0.5f;
else
width = size.Width;
height = size.Height;
}
#endregion
#region --- IDisposable Members ---
bool disposed;
/// <summary>
/// Releases all resources used by this OpenTK.Fonts.TextureFont.
/// </summary>
public void Dispose()
{
GC.SuppressFinalize(this);
Dispose(true);
}
private void Dispose(bool manual)
{
if (!disposed)
{
pack = null;
if (manual)
{
GL.DeleteTextures(1, ref texture);
font.Dispose();
gfx.Dispose();
}
disposed = true;
}
}
~TextureFont()
{
Dispose(false);
}
#endregion
}
}