[add] GetMonitorRefreshRate(int monitor); (#1289)

src/core.c

@@ -1195,6 +1195,22 @@ int GetMonitorPhysicalHeight(int monitor)
     return 0;
 }
 
+int GetMonitorRefreshRate(int monitor)
+{
+#if defined(PLATFORM_DESKTOP)
+    int monitorCount;
+    GLFWmonitor **monitors = glfwGetMonitors(&monitorCount);
+
+    if ((monitor >= 0) && (monitor < monitorCount))
+    {
+        const GLFWvidmode *vidmode = glfwGetVideoMode(monitors[monitor]);
+        return vidmode->refreshRate;
+    }
+    else TRACELOG(LOG_WARNING, "GLFW: Failed to find selected monitor");
+#endif
+    return 0;
+}
+
 // Get window position XY on monitor
 Vector2 GetWindowPosition(void)
 {

src/raylib.h

@@ -892,6 +892,7 @@ RLAPI int GetMonitorWidth(int monitor);                           // Get primary
 RLAPI int GetMonitorHeight(int monitor);                          // Get primary monitor height
 RLAPI int GetMonitorPhysicalWidth(int monitor);                   // Get primary monitor physical width in millimetres
 RLAPI int GetMonitorPhysicalHeight(int monitor);                  // Get primary monitor physical height in millimetres
+RLAPI int GetMonitorRefreshRate(int monitor);                     // Get primary monitor refresh rate
 RLAPI Vector2 GetWindowPosition(void);                            // Get window position XY on monitor
 RLAPI Vector2 GetWindowScaleDPI(void);                            // Get window scale DPI factor
 RLAPI const char *GetMonitorName(int monitor);                    // Get the human-readable, UTF-8 encoded name of the primary monitor