//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
/// <summary>
/// Get typeface metrics of the specified style
/// </summary>
ITypefaceMetrics IFontFamily.GetTypefaceMetrics(
FontStyle style,
FontWeight weight,
FontStretch stretch
)
{
CachedFontFace bestFace = FindNearestTypeface(style, weight, stretch);
if (!bestFace.IsNull)
{
unsafe
{
return(new CompositeTypefaceMetrics(
bestFace.CompositeFace->underlinePosition,
bestFace.CompositeFace->underlineThickness,
bestFace.CompositeFace->strikeThroughPosition,
bestFace.CompositeFace->strikeThroughThickness,
bestFace.CompositeFace->capsHeight,
bestFace.CompositeFace->xHeight,
bestFace.CompositeFace->fontStyle,
bestFace.CompositeFace->fontWeight,
bestFace.CompositeFace->fontStretch
));
}
}
else
{
return(new CompositeTypefaceMetrics());
}
}
/// <summary>
/// Find the face exactly matching the specified style, weight and stretch.
/// Returns CachedFontFace.Null if there is no matching face.
/// </summary>
private CachedFontFace FindExactTypeface(FontStyle style, FontWeight weight, FontStretch stretch)
{
MatchingStyle target = new MatchingStyle(style, weight, stretch);
for (int i = 0; i < _cachedFamily.NumberOfFaces; i++)
{
CachedFontFace currentFace = _cachedFamily.FamilyCollection.GetCachedFace(_cachedFamily, i);
if (currentFace.MatchingStyle == target)
{
return(currentFace);
}
}
return(CachedFontFace.Null);
}
/// <summary>
/// Look up device font for the typeface.
/// </summary>
IDeviceFont IFontFamily.GetDeviceFont(FontStyle style, FontWeight weight, FontStretch stretch)
{
CachedFontFace bestFace = FindExactTypeface(style, weight, stretch);
if (!bestFace.IsNull)
{
unsafe
{
int offsetToDeviceFont = bestFace.CompositeFace->offsetToDeviceFont;
if (offsetToDeviceFont != 0)
{
return(new DeviceFont(
_cachedFamily,
bestFace.CheckedPointer + offsetToDeviceFont
));
}
}
}
return(null);
}
/// <summary>
/// Find the face most closely matching the specified style, weight and stretch.
/// Returns CachedFontFace.Null if there is no available face.
/// </summary>
private CachedFontFace FindNearestTypeface(FontStyle style, FontWeight weight, FontStretch stretch)
{
if (_cachedFamily.NumberOfFaces == 0)
{
return(CachedFontFace.Null);
}
MatchingStyle target = new MatchingStyle(style, weight, stretch);
CachedFontFace bestFace = _cachedFamily.FamilyCollection.GetCachedFace(_cachedFamily, 0);
MatchingStyle bestMatch = bestFace.MatchingStyle;
for (int i = 1; i < _cachedFamily.NumberOfFaces; i++)
{
CachedFontFace currentFace = _cachedFamily.FamilyCollection.GetCachedFace(_cachedFamily, i);
MatchingStyle currentMatch = currentFace.MatchingStyle;
if (MatchingStyle.IsBetterMatch(target, bestMatch, ref currentMatch))
{
bestMatch = currentMatch;
bestFace = currentFace;
}
}
return(bestFace);
}
