Made XInput2 optional at compile-time.

This is required for RHEL 5, CentOS 5 and Cygwin-X.

Fixes #314.

CMakeLists.txt

@@ -273,11 +273,9 @@ if (_GLFW_X11)
     list(APPEND glfw_PKG_DEPS "xinerama")
 
     # Check for XInput (high-resolution cursor motion)
-    if (NOT X11_Xinput_FOUND)
+    if (X11_Xinput_FOUND)
-        message(FATAL_ERROR "The XInput library and headers were not found")
-    endif()
-
         list(APPEND glfw_INCLUDE_DIRS "${X11_Xinput_INCLUDE_PATH}")
+        list(APPEND glfw_PKG_DEPS "xi")
 
         if (X11_Xinput_LIB)
             list(APPEND glfw_LIBRARIES "${X11_Xinput_LIB}")
@@ -285,7 +283,9 @@ if (_GLFW_X11)
             # Backwards compatibility (bug in CMake 2.8.7)
             list(APPEND glfw_LIBRARIES Xi)
         endif()
-    list(APPEND glfw_PKG_DEPS "xi")
+
+        set(_GLFW_HAS_XINPUT TRUE)
+    endif()
 
     # Check for Xf86VidMode (fallback gamma control)
     if (NOT X11_xf86vmode_FOUND)

README.md

@@ -64,6 +64,7 @@ GLFW bundles a number of dependencies in the `deps/` directory.
 
  - [Cocoa] Bugfix: `glfwSetWindowSize` did not change the video mode for full
                    screen windows
+ - [X11] Made XInput2 optional at compile-time
 
 
 ## Contact

docs/compile.dox

@@ -302,6 +302,11 @@ point retrieval mechanism.
  - `_GLFW_HAS_GLXGETPROCADDRESSEXT` to use `glXGetProcAddressEXT` (legacy)
  - `_GLFW_HAS_DLOPEN` to do manual retrieval with `dlopen` (fallback)
 
+In addition, support for the following X11 extensions can be enabled:
+
+ - `_GLFW_HAS_XINPUT` to use XInput2 for high-resolution cursor motion
+ (recommended)
+
 If you are using the Cocoa window creation API, the following options are
 available:
 

src/glfw_config.h.in

@@ -62,6 +62,8 @@
 // Define this to 1 to force use of high-performance GPU on Optimus systems
 #cmakedefine _GLFW_USE_OPTIMUS_HPG
 
+// Define this to 1 if the XInput X11 extension is available
+#cmakedefine _GLFW_HAS_XINPUT
 // Define this to 1 if glXGetProcAddress is available
 #cmakedefine _GLFW_HAS_GLXGETPROCADDRESS
 // Define this to 1 if glXGetProcAddressARB is available

src/x11_init.c

@@ -535,6 +535,7 @@ static GLboolean initExtensions(void)
             _glfw.x11.xinerama.available = GL_TRUE;
     }
 
+#if defined(_GLFW_HAS_XINPUT)
     if (XQueryExtension(_glfw.x11.display,
                         "XInputExtension",
                         &_glfw.x11.xi.majorOpcode,
@@ -551,6 +552,7 @@ static GLboolean initExtensions(void)
             _glfw.x11.xi.available = GL_TRUE;
         }
     }
+#endif /*_GLFW_HAS_XINPUT*/
 
     // Check if Xkb is supported on this display
     _glfw.x11.xkb.versionMajor = 1;

src/x11_platform.h

@@ -43,15 +43,17 @@
 // The XRandR extension provides mode setting and gamma control
 #include <X11/extensions/Xrandr.h>
 
-// The XInput2 extension provides improved input events
-#include <X11/extensions/XInput2.h>
-
 // The Xkb extension provides improved keyboard support
 #include <X11/XKBlib.h>
 
 // The Xinerama extension provides legacy monitor indices
 #include <X11/extensions/Xinerama.h>
 
+#if defined(_GLFW_HAS_XINPUT)
+ // The XInput2 extension provides improved input events
+ #include <X11/extensions/XInput2.h>
+#endif
+
 #include "posix_tls.h"
 
 #if defined(_GLFW_GLX)
@@ -188,15 +190,6 @@ typedef struct _GLFWlibraryX11
         int         versionMinor;
     } xkb;
 
-    struct {
-        GLboolean   available;
-        int         majorOpcode;
-        int         eventBase;
-        int         errorBase;
-        int         versionMajor;
-        int         versionMinor;
-    } xi;
-
     struct {
         int         count;
         int         timeout;
@@ -215,6 +208,17 @@ typedef struct _GLFWlibraryX11
         int         versionMinor;
     } xinerama;
 
+#if defined(_GLFW_HAS_XINPUT)
+    struct {
+        GLboolean   available;
+        int         majorOpcode;
+        int         eventBase;
+        int         errorBase;
+        int         versionMajor;
+        int         versionMinor;
+    } xi;
+#endif /*_GLFW_HAS_XINPUT*/
+
 } _GLFWlibraryX11;
 
 

src/x11_window.c

@@ -412,6 +412,7 @@ static GLboolean createWindow(_GLFWwindow* window,
         XFree(hint);
     }
 
+#if defined(_GLFW_HAS_XINPUT)
     if (_glfw.x11.xi.available)
     {
         // Select for XInput2 events
@@ -426,6 +427,7 @@ static GLboolean createWindow(_GLFWwindow* window,
 
         XISelectEvents(_glfw.x11.display, window->x11.handle, &eventmask, 1);
     }
+#endif /*_GLFW_HAS_XINPUT*/
 
     if (_glfw.x11.XdndAware)
     {
@@ -1310,6 +1312,7 @@ static void processEvent(XEvent *event)
         case DestroyNotify:
             return;
 
+#if defined(_GLFW_HAS_XINPUT)
         case GenericEvent:
         {
             if (event->xcookie.extension == _glfw.x11.xi.majorOpcode &&
@@ -1355,6 +1358,7 @@ static void processEvent(XEvent *event)
             XFreeEventData(_glfw.x11.display, &event->xcookie);
             break;
         }
+#endif /*_GLFW_HAS_XINPUT*/
 
         default:
         {