feat(server): keep last full-frame/desktop update

It should reflect client drawing state.

In following changes, we will fix it to draw bitmap updates on it, to
keep it up to date.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Author: elmarco

crates/ironrdp-server/src/encoder/mod.rs

@@ -4,6 +4,7 @@ pub(crate) mod rfx;
 use core::{cmp, fmt};
 
 use anyhow::{Context, Result};
+use ironrdp_acceptor::DesktopSize;
 use ironrdp_core::{Encode, WriteCursor};
 use ironrdp_pdu::fast_path::{EncryptionFlags, FastPathHeader, FastPathUpdatePdu, Fragmentation, UpdateCode};
 use ironrdp_pdu::geometry::ExclusiveRectangle;
@@ -14,7 +15,7 @@ use ironrdp_pdu::surface_commands::{ExtendedBitmapDataPdu, SurfaceBitsPdu, Surfa
 use self::bitmap::BitmapEncoder;
 use self::rfx::RfxEncoder;
 use super::BitmapUpdate;
-use crate::{ColorPointer, RGBAPointer};
+use crate::{ColorPointer, Framebuffer, RGBAPointer};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[repr(u8)]
@@ -28,6 +29,9 @@ const MAX_FASTPATH_UPDATE_SIZE: usize = 16_374;
 const FASTPATH_HEADER_SIZE: usize = 6;
 
 pub(crate) struct UpdateEncoder {
+    desktop_size: DesktopSize,
+    // FIXME: draw updates on the framebuffer
+    framebuffer: Option<Framebuffer>,
     pdu_encoder: PduEncoder,
     bitmap_updater: BitmapUpdater,
 }
@@ -41,7 +45,7 @@ impl fmt::Debug for UpdateEncoder {
 }
 
 impl UpdateEncoder {
-    pub(crate) fn new(surface_flags: CmdFlags, remotefx: Option<(EntropyBits, u8)>) -> Self {
+    pub(crate) fn new(desktop_size: DesktopSize, surface_flags: CmdFlags, remotefx: Option<(EntropyBits, u8)>) -> Self {
         let pdu_encoder = PduEncoder::new();
         let bitmap_updater = if !surface_flags.contains(CmdFlags::SET_SURFACE_BITS) {
             BitmapUpdater::Bitmap(BitmapHandler::new())
@@ -53,11 +57,17 @@ impl UpdateEncoder {
         };
 
         Self {
+            desktop_size,
+            framebuffer: None,
             pdu_encoder,
             bitmap_updater,
         }
     }
 
+    pub(crate) fn set_desktop_size(&mut self, size: DesktopSize) {
+        self.desktop_size = size;
+    }
+
     pub(crate) fn rgba_pointer(&mut self, ptr: RGBAPointer) -> Result<UpdateFragmenter<'_>> {
         let xor_mask = ptr.data;
 
@@ -114,7 +124,18 @@ impl UpdateEncoder {
     }
 
     pub(crate) fn bitmap(&mut self, bitmap: BitmapUpdate) -> Result<UpdateFragmenter<'_>> {
-        self.bitmap_updater.handle(&bitmap, &mut self.pdu_encoder)
+        let res = self.bitmap_updater.handle(&bitmap, &mut self.pdu_encoder);
+        if bitmap.x == 0
+            && bitmap.y == 0
+            && bitmap.width.get() == self.desktop_size.width
+            && bitmap.height.get() == self.desktop_size.height
+        {
+            match bitmap.try_into() {
+                Ok(framebuffer) => self.framebuffer = Some(framebuffer),
+                Err(err) => warn!("Failed to convert bitmap to framebuffer: {}", err),
+            }
+        }
+        res
     }
 
     pub(crate) fn fragmenter_from_owned(&self, res: UpdateFragmenterOwned) -> UpdateFragmenter<'_> {

crates/ironrdp-server/src/server.rs

@@ -436,6 +436,7 @@ impl RdpServer {
             DisplayUpdate::PointerPosition(pos) => encoder.pointer_position(pos),
             DisplayUpdate::Resize(desktop_size) => {
                 debug!(?desktop_size, "Display resize");
+                encoder.set_desktop_size(desktop_size);
                 deactivate_all(io_channel_id, user_channel_id, writer).await?;
                 return Ok((RunState::DeactivationReactivation { desktop_size }, encoder));
             }
@@ -740,7 +741,8 @@ impl RdpServer {
             }
         }
 
-        let encoder = UpdateEncoder::new(surface_flags, rfxcodec);
+        let desktop_size = self.display.lock().await.size().await;
+        let encoder = UpdateEncoder::new(desktop_size, surface_flags, rfxcodec);
 
         let state = self
             .client_loop(reader, writer, result.io_channel_id, result.user_channel_id, encoder)