static SimpleGlyphFlag[] ReadFlags(BinaryReader input, int flagCount)
{
var result = new SimpleGlyphFlag[flagCount];
int i = 0;
int repeatCount = 0;
var flag = (SimpleGlyphFlag)0;
while (i < flagCount)
{
if (repeatCount > 0)
{
repeatCount--;
}
else
{
flag = (SimpleGlyphFlag)input.ReadByte();
if (HasFlag(flag, SimpleGlyphFlag.Repeat))
{
repeatCount = input.ReadByte();
}
}
result[i++] = flag;
}
return(result);
}
static bool HasFlag(SimpleGlyphFlag target, SimpleGlyphFlag test)
{
return((target & test) == test);
}
static short[] ReadCoordinates(BinaryReader input, int pointCount, SimpleGlyphFlag[] flags, SimpleGlyphFlag isByte, SimpleGlyphFlag signOrSame)
{
//https://www.microsoft.com/typography/OTSPEC/glyf.htm
//Note: In the glyf table, the position of a point is not stored in absolute terms but as a vector relative to the previous point.
//The delta-x and delta-y vectors represent these (often small) changes in position.
//Each flag is a single bit. Their meanings are shown below.
//Bit Flags Description
//0 On Curve If set, the point is on the curve; otherwise, it is off the curve.
//1 x-Short Vector If set, the corresponding x-coordinate is 1 byte long. If not set, 2 bytes.
//2 y-Short Vector If set, the corresponding y-coordinate is 1 byte long. If not set, 2 bytes.
//3 Repeat If set, the next byte specifies the number of additional times this set of flags is to be repeated.
// In this way, the number of flags listed can be smaller than the number of points in a character.
//4 This x is same(Positive x-Short Vector) This flag has two meanings, depending on how the x-Short Vector flag is set.
// If x-Short Vector is set, this bit describes the sign of the value,
// with 1 equalling positive and 0 negative.
// If the x-Short Vector bit is not set and this bit is set, then the current x-coordinate is the same as the previous x-coordinate.
// If the x-Short Vector bit is not set and this bit is also not set, the current x-coordinate is a signed 16-bit delta vector.
//5 This y is same (Positive y-Short Vector) This flag has two meanings,
// depending on how the y-Short Vector flag is set.
// If y-Short Vector is set, this bit describes the sign of the value,
// with 1 equalling positive and 0 negative.
// If the y-Short Vector bit is not set and this bit is set, then the current y-coordinate is the same as the previous y-coordinate.
// If the y-Short Vector bit is not set and this bit is also not set,
// the current y-coordinate is a signed 16-bit delta vector.
//6 Reserved This bit is reserved. Set it to zero.
//7 Reserved This bit is reserved. Set it to zero.
var xs = new short[pointCount];
int x = 0;
for (int i = 0; i < pointCount; i++)
{
int dx;
if (HasFlag(flags[i], isByte))
{
byte b = input.ReadByte();
dx = HasFlag(flags[i], signOrSame) ? b : -b;
}
else
{
if (HasFlag(flags[i], signOrSame))
{
dx = 0;
}
else
{
dx = input.ReadInt16();
}
}
x += dx;
xs[i] = (short)x; // TODO: overflow?
}
return(xs);
}
static SimpleGlyphFlag[] ReadFlags(BinaryReader input, int flagCount)
{
var result = new SimpleGlyphFlag[flagCount];
int i = 0;
int repeatCount = 0;
var flag = (SimpleGlyphFlag)0;
while (i < flagCount)
{
if (repeatCount > 0)
{
repeatCount--;
}
else
{
flag = (SimpleGlyphFlag)input.ReadByte();
if (HasFlag(flag, SimpleGlyphFlag.Repeat))
{
repeatCount = input.ReadByte();
}
}
result[i++] = flag;
}
return result;
}
static bool HasFlag(SimpleGlyphFlag target, SimpleGlyphFlag test)
{
return (target & test) == test;
}
static short[] ReadCoordinates(BinaryReader input, int pointCount, SimpleGlyphFlag[] flags, SimpleGlyphFlag isByte, SimpleGlyphFlag signOrSame)
{
//https://www.microsoft.com/typography/OTSPEC/glyf.htm
//Note: In the glyf table, the position of a point is not stored in absolute terms but as a vector relative to the previous point.
//The delta-x and delta-y vectors represent these (often small) changes in position.
//Each flag is a single bit. Their meanings are shown below.
//Bit Flags Description
//0 On Curve If set, the point is on the curve; otherwise, it is off the curve.
//1 x-Short Vector If set, the corresponding x-coordinate is 1 byte long. If not set, 2 bytes.
//2 y-Short Vector If set, the corresponding y-coordinate is 1 byte long. If not set, 2 bytes.
//3 Repeat If set, the next byte specifies the number of additional times this set of flags is to be repeated.
// In this way, the number of flags listed can be smaller than the number of points in a character.
//4 This x is same(Positive x-Short Vector) This flag has two meanings, depending on how the x-Short Vector flag is set.
// If x-Short Vector is set, this bit describes the sign of the value,
// with 1 equalling positive and 0 negative.
// If the x-Short Vector bit is not set and this bit is set, then the current x-coordinate is the same as the previous x-coordinate.
// If the x-Short Vector bit is not set and this bit is also not set, the current x-coordinate is a signed 16-bit delta vector.
//5 This y is same (Positive y-Short Vector) This flag has two meanings,
// depending on how the y-Short Vector flag is set.
// If y-Short Vector is set, this bit describes the sign of the value,
// with 1 equalling positive and 0 negative.
// If the y-Short Vector bit is not set and this bit is set, then the current y-coordinate is the same as the previous y-coordinate.
// If the y-Short Vector bit is not set and this bit is also not set,
// the current y-coordinate is a signed 16-bit delta vector.
//6 Reserved This bit is reserved. Set it to zero.
//7 Reserved This bit is reserved. Set it to zero.
var xs = new short[pointCount];
int x = 0;
for (int i = 0; i < pointCount; i++)
{
int dx;
if (HasFlag(flags[i], isByte))
{
byte b = input.ReadByte();
dx = HasFlag(flags[i], signOrSame) ? b : -b;
}
else
{
if (HasFlag(flags[i], signOrSame))
{
dx = 0;
}
else
{
dx = input.ReadInt16();
}
}
x += dx;
xs[i] = (short)x; // TODO: overflow?
}
return xs;
}
