2.3.4.4 EmfPlusDrawClosedCurve Record

The EmfPlusDrawClosedCurve record specifies drawing a closed cardinal spline.

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
Type																Flags
Size
DataSize
Tension
Count
PointData (variable)
...

Type (2 bytes): An unsigned integer that identifies this record type as EmfPlusDrawClosedCurve from the RecordType enumeration. The value MUST be 0x4017.

Flags (2 bytes): An unsigned integer that provides information about how the operation is to be performed, and about the structure of the record.

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
X	C	X	X	P	X	X	X	ObjectID

X (1 bit): Reserved and MUST be ignored.

C (1 bit): This bit indicates whether the PointData field specifies compressed data.

If set, PointData specifies locations in the coordinate space with 16-bit signed integer coordinates. If clear, PointData specifies locations in the coordinate space with 32-bit floating-point coordinates.

Note: If the P flag (below) is set, this flag is undefined and MUST be ignored.

P (1 bit): This bit indicates whether the PointData field specifies relative or absolute locations.

If set, each element in PointData specifies a location in the coordinate space that is relative to the location specified by the previous element in the array. In the case of the first element in PointData, a previous location at coordinates (0,0) is assumed. If clear, PointData specifies absolute locations according to the C flag.

Note: If this flag is set, the C flag (above) is undefined and MUST be ignored.<21>

ObjectID (1 byte): The index of an EmfPlusPen object in the EMF+ Object Table to draw the closed curve. The value MUST be zero to 63, inclusive.

Size (4 bytes): An unsigned integer that specifies the 32-bit-aligned number of bytes in the entire record. At least 3 points MUST be specified.

Value	Meaning
0x0000001C ≤ value	If the P bit is set in the Flags field, the minimum Size is computed as follows:  Size = ((((Count * 0x00000002) + 0x00000014 + 0x00000003) / 4) * 4)
0x00000020 ≤ value	If the P bit is clear and the C bit is set in the Flags field, Size is computed as follows:  Size = (Count * 0x00000004) + 0x00000014
0x0000002C ≤ value	If the P bit is clear and the C bit is clear in the Flags field, Size is computed as follows:  Size = (Count * 0x00000008) + 0x00000014

DataSize (4 bytes): An unsigned integer that specifies the 32-bit-aligned number of bytes of record-specific data in the record. At least 3 points MUST be specified.

Value	Meaning
0x00000010 ≤ value	If the P bit is set in the Flags field, the minimum DataSize is computed as follows:  DataSize = ((((Count * 0x00000002) + 0x0000008 + 0x00000003) / 4) * 4)
0x00000014 ≤ value	If the P bit is clear and the C bit is set in the Flags field, DataSize is computed as follows:  DataSize = (Count * 0x00000004) + 0x00000008
0x00000020 ≤ value	If the P bit is clear and the C bit is clear in the Flags field, DataSize is computed as follows:  DataSize = (Count * 0x00000008) + 0x00000008

Tension (4 bytes): A floating-point value that specifies how tightly the spline bends as it passes through the points. A value of 0 specifies that the spline is a sequence of straight lines. As the value increases, the curve becomes more rounded. For more information, see [SPLINE77] and [PETZOLD].

Count (4 bytes): An unsigned integer that specifies the number of points in the PointData field. At least 3 points MUST be specified.

PointData (variable): An array of Count points that specify the endpoints of the lines that define the spline. In a closed cardinal spline, the curve continues through the last point in the PointData array and connects with the first point in the array.

The type of data in this array is specified by the Flags field, as follows:

Data Type	Meaning
EmfPlusPointR object	If the P bit is set in the Flags field, the points specify relative locations.
EmfPlusPoint object	If the P bit is clear and the C bit is set in the Flags field, the points specify absolute locations with 16-bit coordinates.
EmfPlusPointF object	If the P and C bits are clear in the Flags field, the points specify absolute locations with 32-bit coordinates.

See section 2.3.4 for the specification of additional drawing record types.