fix(windows): restore WGC monitor fallback

electron/ipc/handlers.ts

@@ -3055,6 +3055,19 @@ body{background:transparent;overflow:hidden;width:100vw;height:100vh}
           config.displayId = Number.isFinite(screenId) && screenId > 0
             ? screenId
             : Number(getScreen().getPrimaryDisplay().id)
+
+          // Monitor handle IDs can drift across Electron/Windows capture boundaries,
+          // so also provide display bounds for a coordinate-based native fallback.
+          const allDisplays = getScreen().getAllDisplays()
+          const display = allDisplays.find((candidate) => String(candidate.id) === String(config.displayId))
+            ?? getScreen().getPrimaryDisplay()
+
+          if (display) {
+            config.displayX = Math.round(display.bounds.x)
+            config.displayY = Math.round(display.bounds.y)
+            config.displayW = Math.round(display.bounds.width)
+            config.displayH = Math.round(display.bounds.height)
+          }
         }
 
         windowsCaptureOutputBuffer = ''

electron/native/wgc-capture/src/main.cpp

@@ -33,6 +33,11 @@ struct CaptureConfig {
     int fps = 60;
     int width = 0;
     int height = 0;
+    int displayX = 0;
+    int displayY = 0;
+    int displayW = 0;
+    int displayH = 0;
+    bool hasDisplayBounds = false;
     bool captureSystemAudio = false;
     bool captureMic = false;
 };
@@ -127,6 +132,18 @@ static bool parseSimpleJson(const std::string& json, CaptureConfig& config) {
     config.captureSystemAudio = findBool("captureSystemAudio");
     config.captureMic = findBool("captureMic");
 
+    int dx = findInt("displayX");
+    int dy = findInt("displayY");
+    int dw = findInt("displayW");
+    int dh = findInt("displayH");
+    if (dw > 0 && dh > 0) {
+        config.displayX = dx;
+        config.displayY = dy;
+        config.displayW = dw;
+        config.displayH = dh;
+        config.hasDisplayBounds = true;
+    }
+
     return true;
 }
 
@@ -198,6 +215,12 @@ int main(int argc, char* argv[]) {
         }
     } else {
         HMONITOR monitor = findMonitorByDisplayId(config.displayId);
+        if (!monitor && config.hasDisplayBounds) {
+            std::cerr << "Monitor ID match failed, attempting coordinate-based match: "
+                      << config.displayX << "," << config.displayY << " " << config.displayW << "x" << config.displayH << std::endl;
+            monitor = findMonitorByBounds(config.displayX, config.displayY, config.displayW, config.displayH);
+        }
+
         if (!monitor) {
             std::cerr << "ERROR: Could not find monitor for displayId " << config.displayId << std::endl;
             return 1;

electron/native/wgc-capture/src/monitor_utils.cpp

@@ -1,5 +1,6 @@
 #include "monitor_utils.h"
 #include <ShellScalingApi.h>
+#include <iostream>
 
 static BOOL CALLBACK enumMonitorCallback(HMONITOR hMonitor, HDC, LPRECT, LPARAM lParam) {
     auto* monitors = reinterpret_cast<std::vector<MonitorInfo>*>(lParam);
@@ -39,6 +40,33 @@ HMONITOR findMonitorByDisplayId(int64_t displayId) {
     return nullptr;
 }
 
+HMONITOR findMonitorByBounds(int x, int y, int width, int height) {
+    auto monitors = enumerateMonitors();
+
+    for (const auto& m : monitors) {
+        if (m.x == x && m.y == y && m.width == width && m.height == height) {
+            std::cerr << "Found monitor by exact bounds: " << x << "," << y << " " << width << "x" << height << std::endl;
+            return m.handle;
+        }
+    }
+
+    for (const auto& m : monitors) {
+        if (m.x == x && m.y == y) {
+            std::cerr << "Found monitor by top-left point match: " << x << "," << y << std::endl;
+            return m.handle;
+        }
+    }
+
+    RECT rect = { x, y, x + width, y + height };
+    HMONITOR monitor = MonitorFromRect(&rect, MONITOR_DEFAULTTONULL);
+    if (monitor) {
+        std::cerr << "Found monitor via Windows OS MonitorFromRect fallback" << std::endl;
+        return monitor;
+    }
+
+    return nullptr;
+}
+
 MonitorInfo getMonitorInfo(HMONITOR monitor) {
     MonitorInfo info;
     info.handle = monitor;

electron/native/wgc-capture/src/monitor_utils.h

@@ -16,4 +16,5 @@ struct MonitorInfo {
 
 std::vector<MonitorInfo> enumerateMonitors();
 HMONITOR findMonitorByDisplayId(int64_t displayId);
+HMONITOR findMonitorByBounds(int x, int y, int width, int height);
 MonitorInfo getMonitorInfo(HMONITOR monitor);