Add dynamic loading of Win32 touch API

src/win32_init.c

@@ -89,6 +89,22 @@ static GLFWbool initLibraries(void)
         GetProcAddress(_glfw.win32.user32.instance, "SetProcessDPIAware");
     _glfw.win32.user32.ChangeWindowMessageFilterEx = (CHANGEWINDOWMESSAGEFILTEREX_T)
         GetProcAddress(_glfw.win32.user32.instance, "ChangeWindowMessageFilterEx");
+    _glfw.win32.user32.GetTouchInputInfo = (GETTOUCHINPUTINFO_T)
+        GetProcAddress(_glfw.win32.user32.instance, "GetTouchInputInfo");
+    _glfw.win32.user32.CloseTouchInputHandle = (CLOSETOUCHINPUTHANDLE_T)
+        GetProcAddress(_glfw.win32.user32.instance, "CloseTouchInputHandle");
+    _glfw.win32.user32.RegisterTouchWindow = (REGISTERTOUCHWINDOW_T)
+        GetProcAddress(_glfw.win32.user32.instance, "RegisterTouchWindow");
+    _glfw.win32.user32.UnregisterTouchWindow = (UNREGISTERTOUCHWINDOW_T)
+        GetProcAddress(_glfw.win32.user32.instance, "UnregisterTouchWindow");
+
+    if (_glfw.win32.user32.GetTouchInputInfo &&
+        _glfw.win32.user32.CloseTouchInputHandle &&
+        _glfw.win32.user32.RegisterTouchWindow &&
+        _glfw.win32.user32.UnregisterTouchWindow)
+    {
+        _glfw.win32.touch.available = GLFW_TRUE;
+    }
 
     _glfw.win32.dwmapi.instance = LoadLibraryW(L"dwmapi.dll");
     if (_glfw.win32.dwmapi.instance)

src/win32_platform.h

@@ -99,6 +99,34 @@ typedef struct tagCHANGEFILTERSTRUCT
 #endif
 #endif /*Windows 7*/
 
+#if WINVER < 0x0601
+
+#define WM_TOUCH 0x0240
+
+DECLARE_HANDLE(HTOUCHINPUT);
+
+typedef struct tagTOUCHINPUT
+{
+    LONG x;
+    LONG y;
+    HANDLE hSource;
+    DWORD dwID;
+    DWORD dwFlags;
+    DWORD dwMask;
+    DWORD dwTime;
+    ULONG_PTR dwExtraInfo;
+    DWORD cxContact;
+    DWORD cyContext;
+} TOUCHINPUT, *PTOUCHINPUT;
+
+#define TOUCH_COORD_TO_PIXEL(x) ((x) / 100)
+
+#define TOUCHEVENTF_MOVE    0x0001
+#define TOUCHEVENTF_DOWN    0x0002
+#define TOUCHEVENTF_UP      0x0004
+
+#endif /*WINVER < 0x0601*/
+
 // winmm.dll function pointer typedefs
 typedef MMRESULT (WINAPI * JOYGETDEVCAPS_T)(UINT,LPJOYCAPS,UINT);
 typedef MMRESULT (WINAPI * JOYGETPOS_T)(UINT,LPJOYINFO);
@@ -112,8 +140,16 @@ typedef DWORD (WINAPI * TIMEGETTIME_T)(void);
 // user32.dll function pointer typedefs
 typedef BOOL (WINAPI * SETPROCESSDPIAWARE_T)(void);
 typedef BOOL (WINAPI * CHANGEWINDOWMESSAGEFILTEREX_T)(HWND,UINT,DWORD,PCHANGEFILTERSTRUCT);
+typedef BOOL (WINAPI * GETTOUCHINPUTINFO_T)(HTOUCHINPUT,UINT,PTOUCHINPUT,int);
+typedef BOOL (WINAPI * CLOSETOUCHINPUTHANDLE_T)(HTOUCHINPUT);
+typedef BOOL (WINAPI * REGISTERTOUCHWINDOW_T)(HWND,LONG);
+typedef BOOL (WINAPI * UNREGISTERTOUCHWINDOW_T)(HWND);
 #define _glfw_SetProcessDPIAware _glfw.win32.user32.SetProcessDPIAware
 #define _glfw_ChangeWindowMessageFilterEx _glfw.win32.user32.ChangeWindowMessageFilterEx
+#define _glfw_GetTouchInputInfo     _glfw.win32.user32.GetTouchInputInfo
+#define _glfw_CloseTouchInputHandle _glfw.win32.user32.CloseTouchInputHandle
+#define _glfw_RegisterTouchWindow   _glfw.win32.user32.RegisterTouchWindow
+#define _glfw_UnregisterTouchWindow _glfw.win32.user32.UnregisterTouchWindow
 
 // dwmapi.dll function pointer typedefs
 typedef HRESULT (WINAPI * DWMISCOMPOSITIONENABLED_T)(BOOL*);
@@ -186,8 +222,16 @@ typedef struct _GLFWlibraryWin32
         HINSTANCE       instance;
         SETPROCESSDPIAWARE_T SetProcessDPIAware;
         CHANGEWINDOWMESSAGEFILTEREX_T ChangeWindowMessageFilterEx;
+        GETTOUCHINPUTINFO_T     GetTouchInputInfo;
+        CLOSETOUCHINPUTHANDLE_T CloseTouchInputHandle;
+        REGISTERTOUCHWINDOW_T   RegisterTouchWindow;
+        UNREGISTERTOUCHWINDOW_T UnregisterTouchWindow;
     } user32;
 
+    struct {
+        GLFWbool        available;
+    } touch;
+
     // dwmapi.dll
     struct {
         HINSTANCE       instance;

src/win32_window.c

@@ -589,12 +589,16 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
             TOUCHINPUT* inputs;
             UINT count = LOWORD(wParam);
 
+            if (!_glfw.win32.touch.available)
+                return 0;
+
             inputs = (TOUCHINPUT*) malloc(sizeof(TOUCHINPUT) * count);
 
-            if (GetTouchInputInfo((HTOUCHINPUT) lParam,
+            if (_glfw_GetTouchInputInfo((HTOUCHINPUT) lParam,
                                         count, inputs, sizeof(TOUCHINPUT)))
             {
-                int i, width, height;
+                UINT i;
+                int width, height;
 
                 _glfwPlatformGetWindowSize(window, &width, &height);
 
@@ -626,7 +630,7 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
                     }
                 }
 
-                CloseTouchInputHandle((HTOUCHINPUT) lParam);
+                _glfw_CloseTouchInputHandle((HTOUCHINPUT) lParam);
             }
 
             free(inputs);
@@ -1189,10 +1193,13 @@ void _glfwPlatformPostEmptyEvent(void)
 
 void _glfwPlatformSetTouchInput(_GLFWwindow* window, int enabled)
 {
+    if (!_glfw.win32.touch.available)
+        return;
+
     if (enabled)
-        RegisterTouchWindow(window->win32.handle, 0);
+        _glfw_RegisterTouchWindow(window->win32.handle, 0);
     else
-        UnregisterTouchWindow(window->win32.handle);
+        _glfw_UnregisterTouchWindow(window->win32.handle);
 }
 
 void _glfwPlatformGetCursorPos(_GLFWwindow* window, double* xpos, double* ypos)

tests/events.c

@@ -438,13 +438,21 @@ static void monitor_callback(GLFWmonitor* monitor, int event)
     }
 }
 
-static void touch_callback(GLFWwindow* window, int touch, int action, double x, double y)
+static void touch_callback(GLFWwindow* window, int touch, int action)
 {
-    printf("%08x at %0.3f: Touch %i %s at %0.3f %0.3f\n",
+    printf("%08x at %0.3f: Touch %i %s\n",
+           counter++,
+           glfwGetTime(),
+           touch,
+           get_action_name(action));
+}
+
+static void touch_pos_callback(GLFWwindow* window, int touch, double x, double y)
+{
+    printf("%08x at %0.3f: Touch %i position: %0.3f %0.3f\n",
            counter++,
            glfwGetTime(),
            touch,
-           get_action_name(action),
            x, y);
 }
 
@@ -562,6 +570,7 @@ int main(int argc, char** argv)
         glfwSetCharModsCallback(slots[i].window, char_mods_callback);
         glfwSetDropCallback(slots[i].window, drop_callback);
         glfwSetTouchCallback(slots[i].window, touch_callback);
+        glfwSetTouchPosCallback(slots[i].window, touch_pos_callback);
 
         glfwMakeContextCurrent(slots[i].window);
         gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);