2.2.2.2.1.3.2 Create Offscreen Bitmap (CREATE_OFFSCR_BITMAP_ORDER)

The Create Offscreen Bitmap Alternate Secondary Drawing Order is used by the server to instruct the client to create a bitmap of a particular width and height in the Offscreen Bitmap Cache. Support for offscreen bitmap caching is specified in the Offscreen Bitmap Cache Capability Set (see [MS-RDPBCGR] section 2.2.7.1.9).

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
header								flags																cx
...								cy																deleteList (variable)
...

header (1 byte): Alternate Secondary Order Header, as defined in section 2.2.2.2.1.3.1.1. The embedded orderType field MUST be set to TS_ALTSEC_CREATE_OFFSCR_BITMAP (0x01).

flags (2 bytes): A 16-bit, unsigned integer. Operational flags. The format of the flags field is described by the following bitmask diagram:

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
offscreenBitmapId															d

offscreenBitmapId (15 bits): A 15-bit unsigned integer. The index of the Offscreen Bitmap Cache entry wherein the bitmap MUST be created. This value MUST be greater than or equal to 0 and less than the maximum number of entries allowed in the Offscreen Bitmap Cache as specified by the offscreenCacheEntries field of the Offscreen Bitmap Cache Capability Set ([MS-RDPBCGR] section 2.2.7.1.9).

d (1 bit): A 1-bit field. Indicates that the deleteList field is present.

cx (2 bytes): A 16-bit, unsigned integer. The width in pixels of the offscreen bitmap to create.

cy (2 bytes): A 16-bit, unsigned integer. The height in pixels of the offscreen bitmap to create.

deleteList (variable): A collection of Offscreen Bitmap Cache entries that MUST be deleted, stored in an Offscreen Cache Delete List (section 2.2.2.2.1.3.2.1) structure.