2.3.4.15 EmfPlusFillClosedCurve Record

The EmfPlusFillClosedCurve record specifies filling the interior of a closed cardinal spline.

Type (2 bytes): An unsigned integer that identifies this record type as EmfPlusFillClosedCurve from the RecordType enumeration. The value MUST be 0x4016.

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
S	C	W	X	P	X	X	X	X	X	X	X	X	X	X	X

S (1 bit): This bit indicates the type of data in the BrushId field.

If set, BrushId specifies a color as an EmfPlusARGB object. If clear, BrushId contains the index of an EmfPlusBrush object in the EMF+ Object Table.

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

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

W (1 bit): This bit indicates how to perform the fill operation.

If set, the fill is a "winding" fill. If clear, the fill is an "alternate" fill.

X (1 bit): Reserved 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.<24>

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
0x00000020 ≤ value	If the P bit is set in the Flags field, the minimum Size is computed as follows:  Size = ((((Count * 0x00000002) + 0x00000018 + 0x00000003) / 4) * 4)
0x00000024 ≤ 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) + 0x00000018
0x00000030 ≤ 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) + 0x00000018

DataSize (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
0x00000014 ≤ value	If the P bit is set in the Flags field, the minimum DataSize is computed as follows:  DataSize = ((((Count * 0x00000002) + 0x0000000C + 0x00000003) / 4) * 4)
0x00000018 ≤ 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) + 0x0000000C
0x00000024 ≤ 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) + 0x0000000C

BrushId (4 bytes): An unsigned integer that specifies the EmfPlusBrush, the content of which is determined by the S bit in the Flags field. This brush is used to fill the interior of the closed cardinal spline.

Tension (4 bytes): A floating-point value that specifies how tightly the spline bends as it passes through the points. A value of 0.0 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 flag is set in the Flags, 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 signed integer values.
EmfPlusPointF object	If the P bit is clear and the C bit is clear in the Flags field, the points specify absolute locations with 32-bit floating-point values.

An "alternate" fill operation fills areas according to the "even-odd parity" rule. According to this rule, a test point can be determined to be inside or outside a closed curve as follows: Draw a line from the test point to a point that is distant from the curve. If that line crosses the curve an odd number of times, the test point is inside the curve; otherwise, the test point is outside the curve.

A "winding" fill operation fills areas according to the "non-zero" rule. According to this rule, a test point can be de11termined to be inside or outside a closed curve as follows: Draw a line from a test point to a point that is distant from the curve. Count the number of times the curve crosses the test line from left to right, and count the number of times the curve crosses the test line from right to left. If those two numbers are the same, the test point is outside the curve; otherwise, the test point is inside the curve.

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