public override bool SetKerning(int char1, int char2, int kern)
{
int[] metrics = GetMetricsTT(char1);
if (metrics == null)
return false;
int c1 = metrics[0];
metrics = GetMetricsTT(char2);
if (metrics == null)
return false;
int c2 = metrics[0];
kerning[(c1 << 16) + c2] = kern;
return true;
}