[feat] add Windows DXGI/GDI screen capture with WGC→DXGI→GDI fallback support

src/screen_capturer/windows/screen_capturer_gdi.cpp

@@ -0,0 +1,206 @@
+#include "screen_capturer_gdi.h"
+
+#include <algorithm>
+#include <chrono>
+#include <string>
+#include <vector>
+
+#include "libyuv.h"
+#include "rd_log.h"
+
+namespace crossdesk {
+
+namespace {
+std::string WideToUtf8(const std::wstring& wstr) {
+  if (wstr.empty()) return {};
+  int size_needed = WideCharToMultiByte(
+      CP_UTF8, 0, wstr.data(), (int)wstr.size(), nullptr, 0, nullptr, nullptr);
+  std::string result(size_needed, 0);
+  WideCharToMultiByte(CP_UTF8, 0, wstr.data(), (int)wstr.size(), result.data(),
+                      size_needed, nullptr, nullptr);
+  return result;
+}
+
+std::string CleanDisplayName(const std::wstring& wide_name) {
+  std::string name = WideToUtf8(wide_name);
+  name.erase(std::remove_if(name.begin(), name.end(),
+                            [](unsigned char c) { return !std::isalnum(c); }),
+             name.end());
+  return name;
+}
+}  // namespace
+
+ScreenCapturerGdi::ScreenCapturerGdi() {}
+ScreenCapturerGdi::~ScreenCapturerGdi() {
+  Stop();
+  Destroy();
+}
+
+BOOL CALLBACK ScreenCapturerGdi::EnumMonitorProc(HMONITOR hMonitor, HDC, LPRECT,
+                                                 LPARAM data) {
+  auto displays = reinterpret_cast<std::vector<DisplayInfo>*>(data);
+  MONITORINFOEX mi{};
+  mi.cbSize = sizeof(MONITORINFOEX);
+  if (GetMonitorInfo(hMonitor, &mi)) {
+    std::string name = CleanDisplayName(mi.szDevice);
+    bool is_primary = (mi.dwFlags & MONITORINFOF_PRIMARY) ? true : false;
+    DisplayInfo info((void*)hMonitor, name, is_primary, mi.rcMonitor.left,
+                     mi.rcMonitor.top, mi.rcMonitor.right, mi.rcMonitor.bottom);
+    if (is_primary)
+      displays->insert(displays->begin(), info);
+    else
+      displays->push_back(info);
+  }
+  return TRUE;
+}
+
+void ScreenCapturerGdi::EnumerateDisplays() {
+  display_info_list_.clear();
+  EnumDisplayMonitors(nullptr, nullptr, EnumMonitorProc,
+                      (LPARAM)&display_info_list_);
+}
+
+int ScreenCapturerGdi::Init(const int fps, cb_desktop_data cb) {
+  fps_ = fps;
+  callback_ = cb;
+  if (!callback_) {
+    LOG_ERROR("GDI: callback is null");
+    return -1;
+  }
+  EnumerateDisplays();
+  if (display_info_list_.empty()) {
+    LOG_ERROR("GDI: no displays found");
+    return -2;
+  }
+  monitor_index_ = 0;
+  return 0;
+}
+
+int ScreenCapturerGdi::Destroy() {
+  Stop();
+  if (nv12_frame_) {
+    delete[] nv12_frame_;
+    nv12_frame_ = nullptr;
+    nv12_width_ = 0;
+    nv12_height_ = 0;
+  }
+  return 0;
+}
+
+int ScreenCapturerGdi::Start(bool show_cursor) {
+  if (running_) return 0;
+  show_cursor_ = show_cursor;
+  paused_ = false;
+  running_ = true;
+  thread_ = std::thread([this]() { CaptureLoop(); });
+  return 0;
+}
+
+int ScreenCapturerGdi::Stop() {
+  if (!running_) return 0;
+  running_ = false;
+  if (thread_.joinable()) thread_.join();
+  return 0;
+}
+
+int ScreenCapturerGdi::Pause(int monitor_index) {
+  paused_ = true;
+  return 0;
+}
+
+int ScreenCapturerGdi::Resume(int monitor_index) {
+  paused_ = false;
+  return 0;
+}
+
+int ScreenCapturerGdi::SwitchTo(int monitor_index) {
+  if (monitor_index < 0 || monitor_index >= (int)display_info_list_.size()) {
+    LOG_ERROR("GDI: invalid monitor index {}", monitor_index);
+    return -1;
+  }
+  monitor_index_ = monitor_index;
+  LOG_INFO("GDI: switched to monitor {}:{}", monitor_index_.load(),
+           display_info_list_[monitor_index_].name);
+  return 0;
+}
+
+void ScreenCapturerGdi::CaptureLoop() {
+  int interval_ms = fps_ > 0 ? (1000 / fps_) : 16;
+  HDC screen_dc = GetDC(nullptr);
+  while (running_) {
+    if (paused_) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+      continue;
+    }
+    if (!screen_dc) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+      continue;
+    }
+
+    const auto& di = display_info_list_[monitor_index_];
+    int left = di.left;
+    int top = di.top;
+    int width = di.width & ~1;
+    int height = di.height & ~1;
+    if (width <= 0 || height <= 0) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(interval_ms));
+      continue;
+    }
+
+    BITMAPINFO bmi{};
+    bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bmi.bmiHeader.biWidth = width;
+    bmi.bmiHeader.biHeight = -height;
+    bmi.bmiHeader.biPlanes = 1;
+    bmi.bmiHeader.biBitCount = 32;
+    bmi.bmiHeader.biCompression = BI_RGB;
+
+    void* bits = nullptr;
+    HDC mem_dc = CreateCompatibleDC(screen_dc);
+    HBITMAP dib =
+        CreateDIBSection(mem_dc, &bmi, DIB_RGB_COLORS, &bits, nullptr, 0);
+    HGDIOBJ old = SelectObject(mem_dc, dib);
+
+    BitBlt(mem_dc, 0, 0, width, height, screen_dc, left, top,
+           SRCCOPY | CAPTUREBLT);
+
+    if (show_cursor_) {
+      CURSORINFO ci{};
+      ci.cbSize = sizeof(CURSORINFO);
+      if (GetCursorInfo(&ci) && ci.flags == CURSOR_SHOWING && ci.hCursor) {
+        POINT pt = ci.ptScreenPos;
+        int cx = pt.x - left;
+        int cy = pt.y - top;
+        if (cx >= -64 && cy >= -64 && cx < width + 64 && cy < height + 64) {
+          DrawIconEx(mem_dc, cx, cy, ci.hCursor, 0, 0, 0, nullptr, DI_NORMAL);
+        }
+      }
+    }
+
+    int stride_argb = width * 4;
+    int nv12_size = width * height * 3 / 2;
+    if (!nv12_frame_ || nv12_width_ != width || nv12_height_ != height) {
+      delete[] nv12_frame_;
+      nv12_frame_ = new unsigned char[nv12_size];
+      nv12_width_ = width;
+      nv12_height_ = height;
+    }
+
+    libyuv::ARGBToNV12(static_cast<const uint8_t*>(bits), stride_argb,
+                       nv12_frame_, width, nv12_frame_ + width * height, width,
+                       width, height);
+
+    if (callback_) {
+      callback_(nv12_frame_, nv12_size, width, height, di.name.c_str());
+    }
+
+    SelectObject(mem_dc, old);
+    DeleteObject(dib);
+    DeleteDC(mem_dc);
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(interval_ms));
+  }
+  ReleaseDC(nullptr, screen_dc);
+}
+
+}  // namespace crossdesk