/// <summary>
/// Function to retrieve the built in kerning pairs and advancement information for the font.
/// </summary>
/// <param name="graphics">The GDI graphics interface.</param>
/// <param name="font">The GDI font.</param>
/// <param name="allowedCharacters">The list of characters available to the font.</param>
private Dictionary <char, ABC> GetKerningInformation(System.Drawing.Graphics graphics, Font font, IList <char> allowedCharacters)
{
Dictionary <char, ABC> advancementInfo;
KerningPairs.Clear();
IntPtr prevGdiHandle = Win32API.SetActiveFont(graphics, font);
try
{
advancementInfo = Win32API.GetCharABCWidths(allowedCharacters[0], allowedCharacters[allowedCharacters.Count - 1]);
if (!Info.UseKerningPairs)
{
return(advancementInfo);
}
IList <KERNINGPAIR> kerningPairs = Win32API.GetKerningPairs();
foreach (KERNINGPAIR pair in kerningPairs.Where(item => item.KernAmount != 0))
{
var newPair = new GorgonKerningPair(Convert.ToChar(pair.First), Convert.ToChar(pair.Second));
if ((!allowedCharacters.Contains(newPair.LeftCharacter)) ||
(!allowedCharacters.Contains(newPair.RightCharacter)))
{
continue;
}
KerningPairs[newPair] = pair.KernAmount;
}
}
finally
{
Win32API.RestoreActiveObject(prevGdiHandle);
}
return(advancementInfo);
}
/// <summary>
/// Function to measure the width of an individual line of text.
/// </summary>
/// <param name="line">The line to measure.</param>
/// <param name="useOutline"><b>true</b> to use the font outline, <b>false</b> to disregard it.</param>
/// <returns>The width of the line.</returns>
private float GetLineWidth(string line, bool useOutline)
{
float size = 0;
bool firstChar = true;
if (!Glyphs.TryGetValue(Info.DefaultCharacter, out GorgonGlyph defaultGlyph))
{
throw new GorgonException(GorgonResult.CannotEnumerate, string.Format(Resources.GORGFX_ERR_FONT_DEFAULT_CHAR_NOT_VALID, Info.DefaultCharacter));
}
for (int i = 0; i < line.Length; i++)
{
char character = line[i];
if (!Glyphs.TryGetValue(character, out GorgonGlyph glyph))
{
glyph = defaultGlyph;
}
// Skip out on carriage returns and newlines.
if ((character == '\r') ||
(character == '\n'))
{
continue;
}
// Whitespace will use the glyph width.
if (char.IsWhiteSpace(character))
{
size += glyph.Advance;
continue;
}
// Include the initial offset.
if (firstChar)
{
size += (useOutline && glyph.OutlineCoordinates.Width > 0) ? glyph.OutlineOffset.X : glyph.Offset.X;
firstChar = false;
}
size += glyph.Advance;
if (!Info.UseKerningPairs)
{
continue;
}
if ((i == line.Length - 1) ||
(KerningPairs.Count == 0))
{
continue;
}
var kerning = new GorgonKerningPair(character, line[i + 1]);
if (KerningPairs.TryGetValue(kerning, out int kernAmount))
{
size += kernAmount;
}
}
return(size);
}
