/// <summary>
/// Measures the size of the specified substring of text when rendered using this font.
/// </summary>
/// <param name="text">The text to measure.</param>
/// <param name="start">The index of the first character of the substring to measure.</param>
/// <param name="count">The number of characters in the substring to measure.</param>
/// <returns>The size of the specified substring of text when rendered using this font.</returns>
public Size2 MeasureString(String text, Int32 start, Int32 count)
{
Contract.EnsureRange(start >= 0 && start < text.Length, "start");
Contract.EnsureRange(count >= 0 && start + count <= text.Length, "count");
var source = new StringSource(text);
return MeasureString(ref source, start, count);
}
/// <summary>
/// Measures the size of the specified substring of text when rendered using this font.
/// </summary>
/// <param name="source">The text to measure.</param>
/// <param name="start">The index of the first character of the substring to measure.</param>
/// <param name="count">The number of characters in the substring to measure.</param>
/// <returns>The size of the specified substring of text when rendered using this font.</returns>
internal Size2 MeasureString(ref StringSource source, Int32 start, Int32 count)
{
var cx = 0;
var cy = 0;
for (int i = 0; i < count; i++)
{
var character = source[start + i];
switch (character)
{
case '\r':
continue;
case '\n':
cx = 0;
cy = cy + LineSpacing;
continue;
case '\t':
cx = cx + TabWidth;
continue;
}
cx += MeasureGlyph(ref source, start + i).Width;
}
return new Size2(cx, cy + LineSpacing);
}
/// <summary>
/// Measures the specified glyph in a string, taking kerning into account.
/// </summary>
/// <param name="source">The text that contains the glyph to measure.</param>
/// <param name="ix">The index of the glyph to measure.</param>
/// <returns>The size of the specified glyph.</returns>
internal Size2 MeasureGlyph(ref StringSource source, Int32 ix)
{
var c1 = source[ix];
switch (c1)
{
case '\n':
return new Size2(0, LineSpacing);
case '\t':
return new Size2(TabWidth, LineSpacing);
default:
var c2 = (ix + 1 < source.Length) ? source[ix + 1] : (Char?)null;
var glyph = glyphs[c1];
var offset = c2.HasValue ? kerning.Get(c1, c2.GetValueOrDefault()) : 0;
return new Size2(glyph.Width + offset, glyph.Height);
}
}
/// <summary>
/// Measures the size of the specified string of text when rendered using this font.
/// </summary>
/// <param name="text">The text to measure.</param>
/// <returns>The size of the specified string of text when rendered using this font.</returns>
public Size2 MeasureString(StringSegment text)
{
var source = new StringSource(text);
return MeasureString(ref source, 0, text.Length);
}
/// <summary>
/// Measures the specified glyph in a string, taking kerning into account.
/// </summary>
/// <param name="text">The text that contains the glyph to measure.</param>
/// <param name="ix">The index of the glyph to measure.</param>
/// <returns>The size of the specified glyph.</returns>
public Size2 MeasureGlyph(StringSegment text, Int32 ix)
{
var source = new StringSource(text);
return MeasureGlyph(ref source, ix);
}
/// <summary>
/// Measures the size of the specified string of text when rendered using this font.
/// </summary>
/// <param name="text">The text to measure.</param>
/// <returns>The size of the specified string of text when rendered using this font.</returns>
public Size2 MeasureString(StringBuilder text)
{
var source = new StringSource(text);
return(MeasureString(ref source, 0, text.Length));
}
/// <summary>
/// Measures the specified glyph in a string, taking kerning into account.
/// </summary>
/// <param name="text">The text that contains the glyph to measure.</param>
/// <param name="ix">The index of the glyph to measure.</param>
/// <returns>The size of the specified glyph.</returns>
public Size2 MeasureGlyph(StringSegment text, Int32 ix)
{
var source = new StringSource(text);
return(MeasureGlyph(ref source, ix));
}