Added GetCurrentMonitor() function to Get the monitor that contains the greater window area

src/core.c

@@ -938,6 +938,47 @@ int GetMonitorCount(void)
 #endif
 }
 
+int GetCurrentMonitor(void)
+{
+
+    int bestmonitor = 0;
+
+#if defined(PLATFORM_DESKTOP)
+
+    int nmonitors, i;
+    int wx, wy, ww, wh;
+    int mx, my, mw, mh;
+    int overlap, bestoverlap;
+    GLFWmonitor **monitors;
+    const GLFWvidmode *mode;
+
+    bestoverlap = 0;
+
+    glfwGetWindowPos(window, &wx, &wy);
+    glfwGetWindowSize(window, &ww, &wh);
+    monitors = glfwGetMonitors(&nmonitors);
+
+    for (i = 0; i < nmonitors; i++) {
+        mode = glfwGetVideoMode(monitors[i]);
+        glfwGetMonitorPos(monitors[i], &mx, &my);
+        mw = mode->width;
+        mh = mode->height;
+
+        overlap =
+                maxi(0, mini(wx + ww, mx + mw) - maxi(wx, mx)) *
+                maxi(0, mini(wy + wh, my + mh) - maxi(wy, my));
+
+        if (bestoverlap < overlap) {
+            bestoverlap = overlap;
+            bestmonitor = i;
+        }
+    }
+#endif
+    return bestmonitor;
+
+}
+
+
 // Get primary monitor width
 int GetMonitorWidth(int monitor)
 {

src/raylib.h

@@ -878,6 +878,7 @@ RLAPI void *GetWindowHandle(void);                                // Get native
 RLAPI int GetScreenWidth(void);                                   // Get current screen width
 RLAPI int GetScreenHeight(void);                                  // Get current screen height
 RLAPI int GetMonitorCount(void);                                  // Get number of connected monitors
+RLAPI int GetCurrentMonitor(void);                                // Get the monitor that contains the greater window area.
 RLAPI int GetMonitorWidth(int monitor);                           // Get primary monitor width
 RLAPI int GetMonitorHeight(int monitor);                          // Get primary monitor height
 RLAPI int GetMonitorPhysicalWidth(int monitor);                   // Get primary monitor physical width in millimetres