[feat] load wgc from wgc_plugin.dll at runtime and drop direct'windowsapp' linking, refs #74

src/common/platform.cpp

@@ -108,7 +108,7 @@ std::string GetHostName() {
 #ifdef _WIN32
   WSADATA wsaData;
   if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
-    std::cerr << "WSAStartup failed." << std::endl;
+    LOG_ERROR("WSAStartup failed");
     return "";
   }
   if (gethostname(hostname, sizeof(hostname)) == SOCKET_ERROR) {

src/screen_capturer/windows/screen_capturer_win.cpp

@@ -1,17 +1,108 @@
 #include "screen_capturer_win.h"
 
+#include <Windows.h>
+
 #include <cmath>
+#include <filesystem>
 #include <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "rd_log.h"
 #include "screen_capturer_dxgi.h"
 #include "screen_capturer_gdi.h"
-#include "screen_capturer_wgc.h"
+#include "wgc_plugin_api.h"
 
 namespace crossdesk {
 
+namespace {
+
+class WgcPluginCapturer final : public ScreenCapturer {
+ public:
+  using CreateFn = ScreenCapturer* (*)();
+  using DestroyFn = void (*)(ScreenCapturer*);
+
+  static std::unique_ptr<ScreenCapturer> Create() {
+    std::filesystem::path plugin_path;
+    wchar_t module_path[MAX_PATH] = {0};
+    const DWORD len = GetModuleFileNameW(nullptr, module_path, MAX_PATH);
+    if (len == 0 || len >= MAX_PATH) {
+      return nullptr;
+    }
+    plugin_path =
+        std::filesystem::path(module_path).parent_path() / L"wgc_plugin.dll";
+
+    HMODULE module = LoadLibraryW(plugin_path.c_str());
+    if (!module) {
+      return nullptr;
+    }
+
+    auto create_fn = reinterpret_cast<CreateFn>(
+        GetProcAddress(module, "CrossDeskCreateWgcCapturer"));
+    auto destroy_fn = reinterpret_cast<DestroyFn>(
+        GetProcAddress(module, "CrossDeskDestroyWgcCapturer"));
+    if (!create_fn || !destroy_fn) {
+      FreeLibrary(module);
+      return nullptr;
+    }
+
+    ScreenCapturer* impl = create_fn();
+    if (!impl) {
+      FreeLibrary(module);
+      return nullptr;
+    }
+
+    return std::unique_ptr<ScreenCapturer>(
+        new WgcPluginCapturer(module, impl, destroy_fn));
+  }
+
+  ~WgcPluginCapturer() override {
+    if (impl_) {
+      destroy_fn_(impl_);
+      impl_ = nullptr;
+    }
+    if (module_) {
+      FreeLibrary(module_);
+      module_ = nullptr;
+    }
+  }
+
+  int Init(const int fps, cb_desktop_data cb) override {
+    return impl_ ? impl_->Init(fps, std::move(cb)) : -1;
+  }
+  int Destroy() override { return impl_ ? impl_->Destroy() : 0; }
+  int Start(bool show_cursor) override {
+    return impl_ ? impl_->Start(show_cursor) : -1;
+  }
+  int Stop() override { return impl_ ? impl_->Stop() : 0; }
+  int Pause(int monitor_index) override {
+    return impl_ ? impl_->Pause(monitor_index) : -1;
+  }
+  int Resume(int monitor_index) override {
+    return impl_ ? impl_->Resume(monitor_index) : -1;
+  }
+  std::vector<DisplayInfo> GetDisplayInfoList() override {
+    return impl_ ? impl_->GetDisplayInfoList() : std::vector<DisplayInfo>{};
+  }
+  int SwitchTo(int monitor_index) override {
+    return impl_ ? impl_->SwitchTo(monitor_index) : -1;
+  }
+  int ResetToInitialMonitor() override {
+    return impl_ ? impl_->ResetToInitialMonitor() : -1;
+  }
+
+ private:
+  WgcPluginCapturer(HMODULE module, ScreenCapturer* impl, DestroyFn destroy_fn)
+      : module_(module), impl_(impl), destroy_fn_(destroy_fn) {}
+
+  HMODULE module_ = nullptr;
+  ScreenCapturer* impl_ = nullptr;
+  DestroyFn destroy_fn_ = nullptr;
+};
+
+}  // namespace
+
 ScreenCapturerWin::ScreenCapturerWin() {}
 ScreenCapturerWin::~ScreenCapturerWin() { Destroy(); }
 
@@ -40,18 +131,21 @@ int ScreenCapturerWin::Init(const int fps, cb_desktop_data cb) {
 
   int ret = -1;
 
-  impl_ = std::make_unique<ScreenCapturerWgc>();
-  ret = impl_->Init(fps_, cb_);
+  impl_ = WgcPluginCapturer::Create();
+  impl_is_wgc_plugin_ = (impl_ != nullptr);
+  ret = impl_ ? impl_->Init(fps_, cb_) : -1;
   if (ret == 0) {
-    LOG_INFO("Windows capturer: using WGC");
+    LOG_INFO("Windows capturer: using WGC plugin");
     BuildCanonicalFromImpl();
     return 0;
   }
 
-  LOG_WARN("Windows capturer: WGC init failed (ret={}), try DXGI", ret);
+  LOG_WARN("Windows capturer: WGC plugin init failed (ret={}), try DXGI", ret);
   impl_.reset();
+  impl_is_wgc_plugin_ = false;
 
   impl_ = std::make_unique<ScreenCapturerDxgi>();
+  impl_is_wgc_plugin_ = false;
   ret = impl_->Init(fps_, cb_);
   if (ret == 0) {
     LOG_INFO("Windows capturer: using DXGI Desktop Duplication");
@@ -63,6 +157,7 @@ int ScreenCapturerWin::Init(const int fps, cb_desktop_data cb) {
   impl_.reset();
 
   impl_ = std::make_unique<ScreenCapturerGdi>();
+  impl_is_wgc_plugin_ = false;
   ret = impl_->Init(fps_, cb_);
   if (ret == 0) {
     LOG_INFO("Windows capturer: using GDI BitBlt");
@@ -79,6 +174,7 @@ int ScreenCapturerWin::Destroy() {
   if (impl_) {
     impl_->Destroy();
     impl_.reset();
+    impl_is_wgc_plugin_ = false;
   }
   {
     std::lock_guard<std::mutex> lock(alias_mutex_);
@@ -102,13 +198,14 @@ int ScreenCapturerWin::Start(bool show_cursor) {
     int s = cand->Start(show_cursor);
     if (s == 0) {
       impl_ = std::move(cand);
+      impl_is_wgc_plugin_ = false;
       RebuildAliasesFromImpl();
       return true;
     }
     return false;
   };
 
-  if (dynamic_cast<ScreenCapturerWgc*>(impl_.get())) {
+  if (impl_is_wgc_plugin_) {
     if (try_init_start(std::make_unique<ScreenCapturerDxgi>())) {
       LOG_INFO("Windows capturer: fallback to DXGI");
       return 0;

src/screen_capturer/windows/screen_capturer_win.h

@@ -38,6 +38,7 @@ class ScreenCapturerWin : public ScreenCapturer {
 
  private:
   std::unique_ptr<ScreenCapturer> impl_;
+  bool impl_is_wgc_plugin_ = false;
   int fps_ = 60;
   cb_desktop_data cb_;
   cb_desktop_data cb_orig_;

src/screen_capturer/windows/wgc_plugin_api.h

@@ -0,0 +1,29 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2026-03-20
+ * Copyright (c) 2026 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _WGC_PLUGIN_API_H_
+#define _WGC_PLUGIN_API_H_
+
+#include "screen_capturer.h"
+
+namespace crossdesk {
+class ScreenCapturer;
+}
+
+#if defined(_WIN32) && defined(CROSSDESK_WGC_PLUGIN_BUILD)
+#define CROSSDESK_WGC_PLUGIN_API __declspec(dllexport)
+#else
+#define CROSSDESK_WGC_PLUGIN_API
+#endif
+
+extern "C" {
+CROSSDESK_WGC_PLUGIN_API crossdesk::ScreenCapturer*
+CrossDeskCreateWgcCapturer();
+CROSSDESK_WGC_PLUGIN_API void CrossDeskDestroyWgcCapturer(
+    crossdesk::ScreenCapturer* capturer);
+}
+
+#endif

src/screen_capturer/windows/wgc_plugin_entry.cpp

@@ -0,0 +1,13 @@
+#include "screen_capturer_wgc.h"
+#include "wgc_plugin_api.h"
+
+extern "C" {
+
+crossdesk::ScreenCapturer* CrossDeskCreateWgcCapturer() {
+  return new crossdesk::ScreenCapturerWgc();
+}
+
+void CrossDeskDestroyWgcCapturer(crossdesk::ScreenCapturer* capturer) {
+  delete capturer;
+}
+}

src/screen_capturer/windows/wgc_session_impl.cpp

@@ -4,15 +4,14 @@
 
 #include <atomic>
 #include <functional>
-#include <iostream>
 #include <memory>
 
 #include "rd_log.h"
 
-#define CHECK_INIT                            \
-  if (!is_initialized_) {                     \
-    std::cout << "AE_NEED_INIT" << std::endl; \
-    return 4;                                 \
+#define CHECK_INIT             \
+  if (!is_initialized_) {      \
+    LOG_ERROR("AE_NEED_INIT"); \
+    return 4;                  \
   }
 
 #define CHECK_CLOSED                         \
@@ -324,7 +323,7 @@ int WgcSessionImpl::Initialize() {
   if (is_initialized_) return 0;
 
   if (!(d3d11_direct_device_ = CreateD3D11Device())) {
-    std::cout << "AE_D3D_CREATE_DEVICE_FAILED" << std::endl;
+    LOG_ERROR("AE_D3D_CREATE_DEVICE_FAILED");
     return 1;
   }
 

xmake.lua

@@ -37,7 +37,7 @@ add_requires("tinyfiledialogs 3.15.1")
 
 if is_os("windows") then
     add_requires("libyuv", "miniaudio 0.11.21")
-    add_links("Shell32", "windowsapp", "dwmapi", "User32", "kernel32",
+    add_links("Shell32", "dwmapi", "User32", "kernel32",
         "SDL3-static", "gdi32", "winmm", "setupapi", "version",
         "Imm32", "iphlpapi", "d3d11", "dxgi")
     add_cxflags("/WX")
@@ -88,7 +88,9 @@ target("screen_capturer")
     add_includedirs("src/screen_capturer", {public = true})
     if is_os("windows") then
         add_packages("libyuv")
-        add_files("src/screen_capturer/windows/*.cpp")
+        add_files("src/screen_capturer/windows/screen_capturer_dxgi.cpp",
+            "src/screen_capturer/windows/screen_capturer_gdi.cpp",
+            "src/screen_capturer/windows/screen_capturer_win.cpp")
         add_includedirs("src/screen_capturer/windows", {public = true})
     elseif is_os("macosx") then
         add_files("src/screen_capturer/macosx/*.cpp",
@@ -199,6 +201,20 @@ target("gui")
         add_files("src/gui/windows/*.mm")
     end
 
+if is_os("windows") then
+target("wgc_plugin")
+    set_kind("shared")
+    add_packages("libyuv")
+    add_deps("rd_log")
+    add_defines("CROSSDESK_WGC_PLUGIN_BUILD=1")
+    add_links("windowsapp")
+    add_files("src/screen_capturer/windows/screen_capturer_wgc.cpp",
+        "src/screen_capturer/windows/wgc_session_impl.cpp",
+        "src/screen_capturer/windows/wgc_plugin_entry.cpp")
+    add_includedirs("src/common", "src/screen_capturer",
+        "src/screen_capturer/windows")
+end
+
 target("crossdesk")
     set_kind("binary")
     add_deps("rd_log", "common", "gui")