// --- functions ---
/// <summary>Gets data associated with the specified codepoint.</summary>
/// <param name="text">The string containing the codepoint.</param>
/// <param name="offset">The offset at which to read the codepoint. For surrogate pairs, two characters are read, and one otherwise.</param>
/// <param name="texture">Receives the texture that contains the codepoint.</param>
/// <param name="data">Receives the data that describes the codepoint.</param>
/// <returns>The number of characters read.</returns>
public int GetCharacterData(string text, int offset, out Texture texture, out OpenGlFontChar data)
{
int value = char.ConvertToUtf32(text, offset);
int hi = value >> 8;
int lo = value & 0xFF;
if (Tables[hi] == null || Tables[hi].Texture == null)
{
lock (BaseRenderer.GdiPlusLock)
{
Tables[hi] = new OpenGlFontTable(Font, hi << 8);
}
}
texture = Tables[hi].Texture;
data = Tables[hi].Characters[lo];
return(value >= 0x10000 ? 2 : 1);
}
// --- constructors ---
/// <summary>Creates a new table of characters.</summary>
/// <param name="font">The font.</param>
/// <param name="offset">The offset from codepoint U+0000.</param>
public OpenGlFontTable(Font font, int offset)
{
/*
* Measure characters.
* */
Vector2[] physicalSizes = new Vector2[256];
Vector2[] typographicSizes = new Vector2[256];
bitmap = new Bitmap(1, 1, PixelFormat.Format32bppArgb);
Graphics graphics = Graphics.FromImage(bitmap);
graphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
for (int i = 0; i < 256; i++)
{
string character = char.ConvertFromUtf32(offset + i);
SizeF physicalSize = graphics.MeasureString(character, font, int.MaxValue, StringFormat.GenericDefault);
SizeF typographicSize = graphics.MeasureString(character, font, int.MaxValue, StringFormat.GenericTypographic);
physicalSizes[i] = new Vector2((int)Math.Ceiling(physicalSize.Width), (int)Math.Ceiling(physicalSize.Height));
typographicSizes[i] = new Vector2((int)Math.Ceiling(typographicSize.Width == 0.0f ? physicalSize.Width : typographicSize.Width), (int)Math.Ceiling(typographicSize.Height == 0.0f ? physicalSize.Height : typographicSize.Height));
}
graphics.Dispose();
bitmap.Dispose();
/*
* Find suitable bitmap dimensions.
* */
const int border = 1;
double width = border;
double height = border;
double lineWidth = 0;
double lineHeight = 0;
Vector2[] coordinates = new Vector2[256];
for (int i = 0; i < 256; i++)
{
if (i % 16 == 0)
{
// new line
if (lineWidth > width)
{
width = lineWidth;
}
lineWidth = border;
height += lineHeight;
lineHeight = 0;
}
coordinates[i] = new Vector2(lineWidth, height);
lineWidth += physicalSizes[i].X + border;
if (physicalSizes[i].Y + border > lineHeight)
{
lineHeight = physicalSizes[i].Y + border;
}
}
if (lineWidth > width)
{
width = lineWidth;
}
height += lineHeight;
width = (int)RoundToPowerOfTwo((uint)width);
height = (int)RoundToPowerOfTwo((uint)height);
/*
* Draw character to bitmap.
* */
bitmap = new Bitmap((int)width, (int)height, PixelFormat.Format32bppArgb);
graphics = Graphics.FromImage(bitmap);
graphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
graphics.Clear(Color.Black);
Characters = new OpenGlFontChar[256];
for (int i = 0; i < 256; i++)
{
graphics.DrawString(char.ConvertFromUtf32(offset + i), font, Brushes.White, new PointF((float)coordinates[i].X, (float)coordinates[i].Y));
double x0 = (coordinates[i].X - border) / width;
double x1 = (coordinates[i].X + physicalSizes[i].X + border) / width;
double y0 = (coordinates[i].Y - border) / height;
double y1 = (coordinates[i].Y + physicalSizes[i].Y + border) / height;
Characters[i] = new OpenGlFontChar(new Vector4(x0, y0, x1 - x0, y1 - y0), new Vector2(physicalSizes[i].X + 2 * border, physicalSizes[i].Y + 2 * border), typographicSizes[i]);
}
graphics.Dispose();
Texture = new Texture(bitmap);
}
