3.3.5.6 Processing an RDPGFX_SURFACE_TO_CACHE_PDU message
The structure and fields of the RDPGFX_SURFACE_TO_CACHE_PDU message are specified in section 2.2.2.6. The header field MUST be processed as specified in section 3.1.5.1. The surfaceId field MUST identify a valid offscreen surface in the Offscreen Surface (section 3.3.1.6) ADM element. Once the RDPGFX_SURFACE_TO_CACHE_PDU message has been successfully decoded, the pixels in the source rectangle on the source surface (specified in the rectSrc field) MUST be copied to the slot in the Bitmap Cache (section 3.3.1.4) ADM element identified by the cacheSlot field using a SRCCOPY ROP3 operation ([MS-RDPEGDI] section 2.2.2.2.1.1.1.7) and tagged with the key specified in the cacheKey field.