feat(connector): expose SUPPORT_DYN_VC_GFX_PROTOCOL early-cap flag for EGFX clients

Currently, `early_capability_flags` in the GCC core data is built
from a fixed set in `connection.rs`. Clients that want to use the
Graphics Pipeline Extension (MS-RDPEGFX) — by attaching a
DvcClientProcessor for `Microsoft::Windows::RDS::Graphics` — have
no way to set `SUPPORT_DYN_VC_GFX_PROTOCOL` without forking the
connector, and modern Windows servers won't open the EGFX channel
unless the client advertises support.

This commit adds an opt-in `Config.support_dyn_vc_gfx_protocol: bool`
(default `false`). When set, the flag is OR'd into
`early_capability_flags` alongside the existing
`WANT_32_BPP_SESSION` conditional. Existing consumers are
unaffected; the doc comment includes a safety note that setting
this without an EGFX implementation will cause Windows to stop
sending legacy bitmap updates, leaving the desktop blank.

Used downstream by Haven (an Android RDP/VNC client) which
implements EGFX with ClearCodec + RemoteFxProgressive decoders;
this lets us drop the vendored ironrdp-connector fork.

Default `false` to preserve current behaviour.

Author: GlassOnTin

crates/ironrdp-client/src/config.rs

@@ -763,6 +763,7 @@ impl PartialConfig {
             request_data: None,
             pointer_software_rendering: false,
             multitransport_flags: None,
+            support_dyn_vc_gfx_protocol: false,
             compression_type,
             performance_flags: PerformanceFlags::default(),
             timezone_info: TimezoneInfo::default(),

crates/ironrdp-connector/src/connection.rs

@@ -703,6 +703,10 @@ fn create_gcc_blocks<'a>(
                         early_capability_flags |= ClientEarlyCapabilityFlags::WANT_32_BPP_SESSION;
                     }
 
+                    if config.support_dyn_vc_gfx_protocol {
+                        early_capability_flags |= ClientEarlyCapabilityFlags::SUPPORT_DYN_VC_GFX_PROTOCOL;
+                    }
+
                     Some(early_capability_flags)
                 },
                 dig_product_id: Some(config.dig_product_id.clone()),

crates/ironrdp-connector/src/lib.rs

@@ -258,6 +258,34 @@ pub struct Config {
     /// [\[MS-RDPBCGR\] 2.2.1.3.7]: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/861f2bbb-6ca2-4c5a-8c44-0714fa901e70
     /// [`MultiTransportChannelData`]: ironrdp_pdu::gcc::MultiTransportChannelData
     pub multitransport_flags: Option<gcc::MultiTransportFlags>,
+
+    /// Advertise client support for the Graphics Pipeline Extension
+    /// (MS-RDPEGFX) over the Dynamic Virtual Channel.
+    ///
+    /// When `true`, the `SUPPORT_DYN_VC_GFX_PROTOCOL` flag is set in
+    /// [`ClientEarlyCapabilityFlags`], telling the server it may
+    /// negotiate the `Microsoft::Windows::RDS::Graphics` channel for
+    /// surface-based graphics updates instead of (or in addition to)
+    /// the legacy slow-path bitmap protocol.
+    ///
+    /// Setting this **without** wiring an EGFX-capable
+    /// [`DvcClientProcessor`] for that channel will cause modern
+    /// Windows servers to stop sending legacy bitmap updates and
+    /// route everything over EGFX — which the connector consumer
+    /// can't decode, leaving the desktop blank. To enable EGFX:
+    ///
+    /// 1. Set this field to `true`.
+    /// 2. Attach a [`DvcClientProcessor`] for
+    ///    `Microsoft::Windows::RDS::Graphics` via
+    ///    [`ClientConnector::with_static_channel`] +
+    ///    [`ironrdp_dvc::DrdynvcClient::with_dynamic_channel`].
+    /// 3. Decode `ironrdp_pdu::rdp::vc::dvc::gfx::ServerPdu` and
+    ///    paint the surfaces.
+    ///
+    /// Default: `false` (legacy slow-path bitmap only).
+    ///
+    /// [`DvcClientProcessor`]: https://docs.rs/ironrdp-dvc/latest/ironrdp_dvc/trait.DvcClientProcessor.html
+    pub support_dyn_vc_gfx_protocol: bool,
 }
 
 ironrdp_core::assert_impl!(Config: Send, Sync);

crates/ironrdp-testsuite-core/tests/session/autodetect.rs

@@ -53,6 +53,7 @@ fn test_config() -> ironrdp_connector::Config {
         enable_server_pointer: false,
         pointer_software_rendering: false,
         multitransport_flags: None,
+        support_dyn_vc_gfx_protocol: false,
         performance_flags: Default::default(),
         timezone_info: Default::default(),
         alternate_shell: String::new(),

crates/ironrdp-testsuite-extra/tests/main.rs

@@ -392,6 +392,7 @@ fn default_client_config() -> connector::Config {
         enable_server_pointer: true,
         pointer_software_rendering: true,
         multitransport_flags: None,
+        support_dyn_vc_gfx_protocol: false,
         performance_flags: Default::default(),
         timezone_info: Default::default(),
         alternate_shell: String::new(),

crates/ironrdp-web/src/session.rs

@@ -1426,6 +1426,7 @@ fn build_config(
         request_data: None,
         pointer_software_rendering: false,
         multitransport_flags: None,
+        support_dyn_vc_gfx_protocol: false,
         performance_flags: PerformanceFlags::default(),
         desktop_scale_factor: 0,
         hardware_id: None,

crates/ironrdp/examples/screenshot.rs

@@ -265,6 +265,7 @@ fn build_config(
         compression_type,
         pointer_software_rendering: true,
         multitransport_flags: None,
+        support_dyn_vc_gfx_protocol: false,
         performance_flags: PerformanceFlags::default(),
         desktop_scale_factor: 0,
         hardware_id: None,

ffi/src/connector/config.rs

@@ -216,6 +216,7 @@ pub mod ffi {
                 compression_type: None,
                 pointer_software_rendering: self.pointer_software_rendering.unwrap_or(false),
                 multitransport_flags: None,
+                support_dyn_vc_gfx_protocol: false,
                 performance_flags: self.performance_flags.ok_or("performance flag is missing")?,
                 desktop_scale_factor: 0,
                 hardware_id: None,