internal FakeFontInstance(
NameTable nameTable,
MaximumProfileTable maxpTable,
CMapTable cmap,
GlyphTable glyphs,
OS2Table os2,
HorizontalHeadTable horizontalHeadTable,
HorizontalMetricsTable horizontalMetrics,
VerticalHeadTable verticalHeadTable,
VerticalMetricsTable verticalMetrics,
HeadTable head,
KerningTable kern)
: base(
nameTable,
maxpTable,
cmap,
glyphs,
os2,
horizontalHeadTable,
horizontalMetrics,
verticalHeadTable,
verticalMetrics,
head,
kern,
null,
null,
null,
null,
null,
null,
null,
null)
{
}
/**
* Builds vertical metrics with a custom CIDToGIDMap (for embedding font subset).
*/
private void BuildVerticalMetrics(Dictionary <int, int> cidToGid)
{
// The "vhea" and "vmtx" tables that specify vertical metrics shall never be used by a conforming
// reader. The only way to specify vertical metrics in PDF shall be by means of the DW2 and W2
// entries in a CIDFont dictionary.
if (!BuildVerticalHeader(cidFont))
{
return;
}
float scaling = 1000f / ttf.Header.UnitsPerEm;
VerticalHeaderTable vhea = ttf.VerticalHeader;
VerticalMetricsTable vmtx = ttf.VerticalMetrics;
GlyphTable glyf = ttf.Glyph;
HorizontalMetricsTable hmtx = ttf.HorizontalMetrics;
long v_y = (long)Math.Round(vhea.Ascender * scaling);
long w1 = (long)Math.Round(-vhea.AdvanceHeightMax * scaling);
PdfArray heights = new PdfArray();
PdfArray w2 = new PdfArray();
int prev = int.MinValue;
// Use a sorted list to get an optimal width array
ISet <int> keys = new HashSet <int>(cidToGid.Keys);
foreach (int cid in keys)
{
// Unlike buildWidths, we look up with cid (not gid) here because this is
// the original TTF, not the rebuilt one.
GlyphData glyph = glyf.GetGlyph(cid);
if (glyph == null)
{
continue;
}
long height = (long)Math.Round((glyph.YMaximum + vmtx.GetTopSideBearing(cid)) * scaling);
long advance = (long)Math.Round(-vmtx.GetAdvanceHeight(cid) * scaling);
if (height == v_y && advance == w1)
{
// skip default metrics
continue;
}
// c [w1_1y v_1x v_1y w1_2y v_2x v_2y ... w1_ny v_nx v_ny]
if (prev != cid - 1)
{
w2 = new PdfArray();
heights.Add(PdfInteger.Get(cid)); // c
heights.Add(w2);
}
w2.Add(PdfInteger.Get(advance)); // w1_iy
long width = (long)Math.Round(hmtx.GetAdvanceWidth(cid) * scaling);
w2.Add(PdfInteger.Get(width / 2)); // v_ix
w2.Add(PdfInteger.Get(height)); // v_iy
prev = cid;
}
cidFont[PdfName.W2] = heights;
}
