3.3.5.1.3.1.1 Construction of Create Offscreen Bitmap

The structure and fields of the Create Offscreen Bitmap Alternate Secondary Drawing Order are specified in section 2.2.2.2.1.3.2. The order fields MUST be populated in accordance with this description.

The offscreen bitmaps managed by the Create Offscreen Bitmap Alternate Secondary Drawing Order are specified in the Switch Surface Alternate Secondary Drawing Order (see section 3.3.5.1.3.1.2). The Switch Surface Order allows the server to change the default client rendering surface to any one of the bitmaps created in the Offscreen Bitmap Cache by the Create Offscreen Order. Once drawing to an offscreen bitmap is complete, the server MUST direct the client to render the bitmap data to the primary drawing surface by using the MemBlt (see section 3.3.5.1.1.1.9) or Mem3Blt (see section 3.3.5.1.1.1.10) Primary Drawing Order.

The Create Offscreen Bitmap Order MUST NOT be sent to the client if support for offscreen bitmap caching was not specified using the Offscreen Bitmap Cache Capability Set (see [MS-RDPBCGR] section 2.2.7.1.9), or if offscreen bitmap caching has been disabled due to the reception of an Offscreen Bitmap Cache Error PDU (see section 3.3.5.2.2). Furthermore, if client-side support for the MemBlt and Mem3Blt Primary Drawing Orders does not exist (specified using the Order Capability Set specified in [MS-RDPBCGR] section 2.2.7.1.3), the Create Offscreen Bitmap Order SHOULD NOT be sent to the client.