Win32: Disable mouse trails for full screen

When mouse trails are enabled, the cursor becomes invisible when the
OpenGL ICD detects a full screen window and switches to page flipping.

Mouse trails are now disabled as long as any full screen windows are
visible.

Fixes #1263.

src/win32_platform.h

@@ -142,6 +142,9 @@ typedef enum
 
 // HACK: Define versionhelpers.h functions manually as MinGW lacks the header
 BOOL IsWindowsVersionOrGreater(WORD major, WORD minor, WORD sp);
+#define IsWindowsXPOrGreater()                                 \
+    IsWindowsVersionOrGreater(HIBYTE(_WIN32_WINNT_WINXP),      \
+                              LOBYTE(_WIN32_WINNT_WINXP), 0)
 #define IsWindowsVistaOrGreater()                              \
     IsWindowsVersionOrGreater(HIBYTE(_WIN32_WINNT_VISTA),      \
                               LOBYTE(_WIN32_WINNT_VISTA), 0)
@@ -300,6 +303,7 @@ typedef struct _GLFWlibraryWin32
     _GLFWwindow*        disabledCursorWindow;
     RAWINPUT*           rawInput;
     int                 rawInputSize;
+    UINT                mouseTrailSize;
 
     struct {
         HINSTANCE                       instance;

src/win32_window.c

@@ -529,7 +529,18 @@ static void fitToMonitor(_GLFWwindow* window)
 static void acquireMonitor(_GLFWwindow* window)
 {
     if (!_glfw.win32.acquiredMonitorCount)
+    {
         SetThreadExecutionState(ES_CONTINUOUS | ES_DISPLAY_REQUIRED);
+
+        // HACK: When mouse trails are enabled the cursor becomes invisible when
+        //       the OpenGL ICD switches to page flipping
+        if (IsWindowsXPOrGreater())
+        {
+            SystemParametersInfo(SPI_GETMOUSETRAILS, 0, &_glfw.win32.mouseTrailSize, 0);
+            SystemParametersInfo(SPI_SETMOUSETRAILS, 0, 0, 0);
+        }
+    }
+
     if (!window->monitor->window)
         _glfw.win32.acquiredMonitorCount++;
 
@@ -546,8 +557,14 @@ static void releaseMonitor(_GLFWwindow* window)
 
     _glfw.win32.acquiredMonitorCount--;
     if (!_glfw.win32.acquiredMonitorCount)
+    {
         SetThreadExecutionState(ES_CONTINUOUS);
 
+        // HACK: Restore mouse trail length saved in acquireMonitor
+        if (IsWindowsXPOrGreater())
+            SystemParametersInfo(SPI_SETMOUSETRAILS, _glfw.win32.mouseTrailSize, 0, 0);
+    }
+
     _glfwInputMonitorWindow(window->monitor, NULL);
     _glfwRestoreVideoModeWin32(window->monitor);
 }