MIL-STD-2301 Computer Graphics Metafile Cgm Implementation Standard For The National Imagery Transmission Format StandardThis standard establishes the requirements necessary to implement Computer Graphics Metafiles CGM used for the representation of symbol graphics in the National Imagery Transmission Format Standard NITFS.

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MIL-STD-2301A

TABLE CXIV. Circular Arc Center Close output.

MSB                                                                                                                                                               LSB

15        14      13       12       11       10        9         8         7         6          5         4         3          2       1         0

4                                                           16                                                               16                                  0x4210

CenterX CenterY StartX StartY EndX EndY Radius Close Type

5.1.2.6  Control elements.  The following control elements are used to describe the visual effects of auxiliary color and transparency.

5.1.2.6.1  Auxiliary Color. The CGM implementation for NITFS shall provide the capability to generate and output the Auxiliary Color element using the following format.  The Auxiliary Color element is used in conjunction with the LINE TYPE, EDGE TYPE, and TEXT.  The Red, Green, and Blue (RGB) values are specified using a single byte.  The last byte of the command shall be a null byte.

TABLE CXV.  Auxiliary Color input.

MSB                                                                                                                                                               LSB

15        14      13       12       11       10        9         8         7         6          5         4         3          2       1         0

3                                                            3                                                                  3                                   0x3063

RED                                                                               GREEN BLUE                                                                                    0

5.1.2.6.2  Transparency.  The CGM implementation for NITFS shall provide the capability to generate

and output the Transparency element using the following format.  The TRANSPARENCY parameter can be off (0)

or on (1).

TABLE CXVI.  Transparency input.

MSB                                                                                                                                                               LSB

15        14      13       12       11       10        9         8         7         6          5         4         3          2       1         0

3                                                            4                                                                  2                                   0x3082

TRANSPARENCY

5.1.2.7  CGM binary encoding.  The CGM elements are represented in the binary encoding format as described in the FIPS PUB 128 document.

5.1.2.7.1  CGM binary encoding for output.  The CGM implementation for NITFS shall provide the capability to generate and output the CGM elements in the binary encoding format.

5.2  Functional requirements. The CGM implementation for NITFS complies with the specifications established in FIPS PUB 128.  The following requirements establish the element position and functional requirements for the CGM implementation for NITFS.  The words "command" and "element" are used synonymously throughout this document.

5.2.1  CGM element position requirements.

5.2.1.1  CGM element position input requirements.

5.2.1.1.1  Begin Metafile element position for input.  The CGM implementation for NITFS shall interpret the Begin Metafile element as the first command in the metafile.

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