private unsafe FamilyCollection.CachedCharacterMetrics *LookupMetrics(int unicodeScalar)
{
if (unicodeScalar >= 0 && unicodeScalar <= FontFamilyMap.LastUnicodeScalar)
{
int pageTableOffset = _deviceFont->OffsetToCharacterMap;
int *pageTable = (int *)CheckedPointer.Probe(
pageTableOffset,
CharacterMetricsDictionary.PageCount * sizeof(int)
);
int i = pageTable[unicodeScalar >> CharacterMetricsDictionary.PageShift];
if (i != 0)
{
int *page = (int *)CheckedPointer.Probe(
pageTableOffset + (i * sizeof(int)),
CharacterMetricsDictionary.PageSize * sizeof(int)
);
int offset = page[unicodeScalar & CharacterMetricsDictionary.PageMask];
if (offset != 0)
{
return((FamilyCollection.CachedCharacterMetrics *)CheckedPointer.Probe(
offset,
sizeof(FamilyCollection.CachedCharacterMetrics)
));
}
}
}
return(null);
}
private static int ReadOpenTypeLong(CheckedPointer pointer)
{
unsafe
{
byte *readBuffer = (byte *)pointer.Probe(0, 4);
int result = (int)((((((readBuffer[0] << 8) + readBuffer[1]) << 8) + readBuffer[2]) << 8) + readBuffer[3]);
return(result);
}
}
/// <summary>
/// The follwoing APIs extract OpenType variable types from OpenType font
/// files. OpenType variables are stored big-endian, and the type are named
/// as follows:
/// Byte - signed 8 bit
/// UShort - unsigned 16 bit
/// Short - signed 16 bit
/// ULong - unsigned 32 bit
/// Long - signed 32 bit
/// </summary>
private static ushort ReadOpenTypeUShort(CheckedPointer pointer)
{
unsafe
{
byte * readBuffer = (byte *)pointer.Probe(0, 2);
ushort result = (ushort)((readBuffer[0] << 8) + readBuffer[1]);
return(result);
}
}
internal DeviceFont(CachedFontFamily cachedFamily, CheckedPointer deviceFont)
{
unsafe
{
_cachedFamily = cachedFamily;
_deviceFont = (FamilyCollection.CachedDeviceFont *)deviceFont.Probe(0, sizeof(FamilyCollection.CachedDeviceFont));
_sizeInBytes = deviceFont.Size;
}
}
private static int ReadOpenTypeLong(CheckedPointer pointer)
{
unsafe
{
byte * readBuffer = (byte *)pointer.Probe(0, 4);
int result = (int)((((((readBuffer[0] << 8) + readBuffer[1]) << 8) + readBuffer[2]) << 8) + readBuffer[3]);
return result;
}
}
private static ushort ReadOpenTypeUShort(CheckedPointer pointer)
{
unsafe
{
byte * readBuffer = (byte *)pointer.Probe(0, 2);
ushort result = (ushort)((readBuffer[0] << 8) + readBuffer[1]);
return result;
}
}