src/core/windows/SDL_xinput.c
author Sam Lantinga <slouken@libsdl.org>
Fri, 22 May 2020 16:45:02 -0700
changeset 13846 599a8525ff0e
parent 13422 fd6a12de91c7
permissions -rw-r--r--
Added a note not to use XinputUap.dll for XInput support
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "../../SDL_internal.h"
    22 
    23 #include "SDL_assert.h"
    24 #include "SDL_xinput.h"
    25 
    26 
    27 #ifdef HAVE_XINPUT_H
    28 
    29 XInputGetState_t SDL_XInputGetState = NULL;
    30 XInputSetState_t SDL_XInputSetState = NULL;
    31 XInputGetCapabilities_t SDL_XInputGetCapabilities = NULL;
    32 XInputGetBatteryInformation_t SDL_XInputGetBatteryInformation = NULL;
    33 DWORD SDL_XInputVersion = 0;
    34 
    35 static HANDLE s_pXInputDLL = 0;
    36 static int s_XInputDLLRefCount = 0;
    37 
    38 
    39 #ifdef __WINRT__
    40 
    41 int
    42 WIN_LoadXInputDLL(void)
    43 {
    44     /* Getting handles to system dlls (via LoadLibrary and its variants) is not
    45      * supported on WinRT, thus, pointers to XInput's functions can't be
    46      * retrieved via GetProcAddress.
    47      *
    48      * When on WinRT, assume that XInput is already loaded, and directly map
    49      * its XInput.h-declared functions to the SDL_XInput* set of function
    50      * pointers.
    51      *
    52      * Side-note: XInputGetStateEx is not available for use in WinRT.
    53      * This seems to mean that support for the guide button is not available
    54      * in WinRT, unfortunately.
    55      */
    56     SDL_XInputGetState = (XInputGetState_t)XInputGetState;
    57     SDL_XInputSetState = (XInputSetState_t)XInputSetState;
    58     SDL_XInputGetCapabilities = (XInputGetCapabilities_t)XInputGetCapabilities;
    59     SDL_XInputGetBatteryInformation = (XInputGetBatteryInformation_t)XInputGetBatteryInformation;
    60 
    61     /* XInput 1.4 ships with Windows 8 and 8.1: */
    62     SDL_XInputVersion = (1 << 16) | 4;
    63 
    64     return 0;
    65 }
    66 
    67 void
    68 WIN_UnloadXInputDLL(void)
    69 {
    70 }
    71 
    72 #else /* !__WINRT__ */
    73 
    74 int
    75 WIN_LoadXInputDLL(void)
    76 {
    77     DWORD version = 0;
    78 
    79     if (s_pXInputDLL) {
    80         SDL_assert(s_XInputDLLRefCount > 0);
    81         s_XInputDLLRefCount++;
    82         return 0;  /* already loaded */
    83     }
    84 
    85     /* NOTE: Don't load XinputUap.dll
    86      * This is XInput emulation over Windows.Gaming.Input, and has all the
    87      * limitations of that API (no devices at startup, no background input, etc.)
    88      */
    89     version = (1 << 16) | 4;
    90     s_pXInputDLL = LoadLibrary(L"XInput1_4.dll");  /* 1.4 Ships with Windows 8. */
    91     if (!s_pXInputDLL) {
    92         version = (1 << 16) | 3;
    93         s_pXInputDLL = LoadLibrary(L"XInput1_3.dll");  /* 1.3 can be installed as a redistributable component. */
    94     }
    95     if (!s_pXInputDLL) {
    96         s_pXInputDLL = LoadLibrary(L"bin\\XInput1_3.dll");
    97     }
    98     if (!s_pXInputDLL) {
    99         /* "9.1.0" Ships with Vista and Win7, and is more limited than 1.3+ (e.g. XInputGetStateEx is not available.)  */
   100         s_pXInputDLL = LoadLibrary(L"XInput9_1_0.dll");
   101     }
   102     if (!s_pXInputDLL) {
   103         return -1;
   104     }
   105 
   106     SDL_assert(s_XInputDLLRefCount == 0);
   107     SDL_XInputVersion = version;
   108     s_XInputDLLRefCount = 1;
   109 
   110     /* 100 is the ordinal for _XInputGetStateEx, which returns the same struct as XinputGetState, but with extra data in wButtons for the guide button, we think... */
   111     SDL_XInputGetState = (XInputGetState_t)GetProcAddress((HMODULE)s_pXInputDLL, (LPCSTR)100);
   112     if (!SDL_XInputGetState) {
   113         SDL_XInputGetState = (XInputGetState_t)GetProcAddress((HMODULE)s_pXInputDLL, "XInputGetState");
   114     }
   115     SDL_XInputSetState = (XInputSetState_t)GetProcAddress((HMODULE)s_pXInputDLL, "XInputSetState");
   116     SDL_XInputGetCapabilities = (XInputGetCapabilities_t)GetProcAddress((HMODULE)s_pXInputDLL, "XInputGetCapabilities");
   117     SDL_XInputGetBatteryInformation = (XInputGetBatteryInformation_t)GetProcAddress( (HMODULE)s_pXInputDLL, "XInputGetBatteryInformation" );
   118     if (!SDL_XInputGetState || !SDL_XInputSetState || !SDL_XInputGetCapabilities) {
   119         WIN_UnloadXInputDLL();
   120         return -1;
   121     }
   122 
   123     return 0;
   124 }
   125 
   126 void
   127 WIN_UnloadXInputDLL(void)
   128 {
   129     if (s_pXInputDLL) {
   130         SDL_assert(s_XInputDLLRefCount > 0);
   131         if (--s_XInputDLLRefCount == 0) {
   132             FreeLibrary(s_pXInputDLL);
   133             s_pXInputDLL = NULL;
   134         }
   135     } else {
   136         SDL_assert(s_XInputDLLRefCount == 0);
   137     }
   138 }
   139 
   140 #endif /* __WINRT__ */
   141 #endif /* HAVE_XINPUT_H */
   142 
   143 /* vi: set ts=4 sw=4 expandtab: */