/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2004 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* SDL joystick driver for Darwin / MacOS X, based on the IOKit HID API */ /* Written 2001 by Max Horn */ #include #include #include #include #include #include #include #ifdef MACOS_10_0_4 #include #else /* The header was moved here in MacOS X 10.1 */ #include #endif #include #include #include #include /* for NewPtrClear, DisposePtr */ #include "SDL_joystick.h" #include "../SDL_sysjoystick.h" #include "../SDL_joystick_c.h" struct recElement { IOHIDElementCookie cookie; // unique value which identifies element, will NOT change long min; // reported min value possible long max; // reported max value possible /* TODO: maybe should handle the following stuff somehow? long scaledMin; // reported scaled min value possible long scaledMax; // reported scaled max value possible long size; // size in bits of data return from element Boolean relative; // are reports relative to last report (deltas) Boolean wrapping; // does element wrap around (one value higher than max is min) Boolean nonLinear; // are the values reported non-linear relative to element movement Boolean preferredState; // does element have a preferred state (such as a button) Boolean nullState; // does element have null state */ /* runtime variables used for auto-calibration */ long minReport; // min returned value long maxReport; // max returned value struct recElement * pNext; // next element in list }; typedef struct recElement recElement; struct joystick_hwdata { IOHIDDeviceInterface ** interface; // interface to device, NULL = no interface char product[256]; // name of product long usage; // usage page from IOUSBHID Parser.h which defines general usage long usagePage; // usage within above page from IOUSBHID Parser.h which defines specific usage long axes; // number of axis (calculated, not reported by device) long buttons; // number of buttons (calculated, not reported by device) long hats; // number of hat switches (calculated, not reported by device) long elements; // number of total elements (shouldbe total of above) (calculated, not reported by device) recElement* firstAxis; recElement* firstButton; recElement* firstHat; int removed; int uncentered; struct joystick_hwdata* pNext; // next device }; typedef struct joystick_hwdata recDevice; /* Linked list of all available devices */ static recDevice *gpDeviceList = NULL; static void HIDReportErrorNum (char * strError, long numError) { SDL_SetError(strError); } static void HIDGetCollectionElements (CFMutableDictionaryRef deviceProperties, recDevice *pDevice); /* returns current value for element, polling element * will return 0 on error conditions which should be accounted for by application */ static SInt32 HIDGetElementValue (recDevice *pDevice, recElement *pElement) { IOReturn result = kIOReturnSuccess; IOHIDEventStruct hidEvent; hidEvent.value = 0; if (NULL != pDevice && NULL != pElement && NULL != pDevice->interface) { result = (*(pDevice->interface))->getElementValue(pDevice->interface, pElement->cookie, &hidEvent); if (kIOReturnSuccess == result) { /* record min and max for auto calibration */ if (hidEvent.value < pElement->minReport) pElement->minReport = hidEvent.value; if (hidEvent.value > pElement->maxReport) pElement->maxReport = hidEvent.value; } } // auto user scale return hidEvent.value; } /* similiar to HIDGetElementValue, but auto-calibrates the value before returning it */ static SInt32 HIDCalibratedValue (recDevice *pDevice, recElement *pElement) { float deviceScale = pElement->max - pElement->min; float readScale = pElement->maxReport - pElement->minReport; SInt32 value = HIDGetElementValue(pDevice, pElement); if (readScale == 0) return value; // no scaling at all else return ((value - pElement->minReport) * deviceScale / readScale) + pElement->min; } /* similiar to HIDCalibratedValue but calibrates to an arbitrary scale instead of the elements default scale */ static SInt32 HIDScaledCalibratedValue (recDevice *pDevice, recElement *pElement, long min, long max) { float deviceScale = max - min; float readScale = pElement->maxReport - pElement->minReport; SInt32 value = HIDGetElementValue(pDevice, pElement); if (readScale == 0) return value; // no scaling at all else return ((value - pElement->minReport) * deviceScale / readScale) + min; } static void HIDRemovalCallback(void * target, IOReturn result, void * refcon, void * sender) { recDevice *device = (recDevice *) refcon; device->removed = 1; device->uncentered = 1; } /* Create and open an interface to device, required prior to extracting values or building queues. * Note: appliction now owns the device and must close and release it prior to exiting */ static IOReturn HIDCreateOpenDeviceInterface (io_object_t hidDevice, recDevice *pDevice) { IOReturn result = kIOReturnSuccess; HRESULT plugInResult = S_OK; SInt32 score = 0; IOCFPlugInInterface ** ppPlugInInterface = NULL; if (NULL == pDevice->interface) { result = IOCreatePlugInInterfaceForService (hidDevice, kIOHIDDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &ppPlugInInterface, &score); if (kIOReturnSuccess == result) { // Call a method of the intermediate plug-in to create the device interface plugInResult = (*ppPlugInInterface)->QueryInterface (ppPlugInInterface, CFUUIDGetUUIDBytes (kIOHIDDeviceInterfaceID), (void *) &(pDevice->interface)); if (S_OK != plugInResult) HIDReportErrorNum ("CouldnŐt query HID class device interface from plugInInterface", plugInResult); (*ppPlugInInterface)->Release (ppPlugInInterface); } else HIDReportErrorNum ("Failed to create **plugInInterface via IOCreatePlugInInterfaceForService.", result); } if (NULL != pDevice->interface) { result = (*(pDevice->interface))->open (pDevice->interface, 0); if (kIOReturnSuccess != result) HIDReportErrorNum ("Failed to open pDevice->interface via open.", result); else (*(pDevice->interface))->setRemovalCallback (pDevice->interface, HIDRemovalCallback, pDevice, pDevice); } return result; } /* Closes and releases interface to device, should be done prior to exting application * Note: will have no affect if device or interface do not exist * application will "own" the device if interface is not closed * (device may have to be plug and re-plugged in different location to get it working again without a restart) */ static IOReturn HIDCloseReleaseInterface (recDevice *pDevice) { IOReturn result = kIOReturnSuccess; if ((NULL != pDevice) && (NULL != pDevice->interface)) { // close the interface result = (*(pDevice->interface))->close (pDevice->interface); if (kIOReturnNotOpen == result) { // do nothing as device was not opened, thus can't be closed } else if (kIOReturnSuccess != result) HIDReportErrorNum ("Failed to close IOHIDDeviceInterface.", result); //release the interface result = (*(pDevice->interface))->Release (pDevice->interface); if (kIOReturnSuccess != result) HIDReportErrorNum ("Failed to release IOHIDDeviceInterface.", result); pDevice->interface = NULL; } return result; } /* extracts actual specific element information from each element CF dictionary entry */ static void HIDGetElementInfo (CFTypeRef refElement, recElement *pElement) { long number; CFTypeRef refType; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementCookieKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->cookie = (IOHIDElementCookie) number; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementMinKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->min = number; pElement->maxReport = pElement->min; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementMaxKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->max = number; pElement->minReport = pElement->max; /* TODO: maybe should handle the following stuff somehow? refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementScaledMinKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->scaledMin = number; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementScaledMaxKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->scaledMax = number; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementSizeKey)); if (refType && CFNumberGetValue (refType, kCFNumberLongType, &number)) pElement->size = number; refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementIsRelativeKey)); if (refType) pElement->relative = CFBooleanGetValue (refType); refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementIsWrappingKey)); if (refType) pElement->wrapping = CFBooleanGetValue (refType); refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementIsNonLinearKey)); if (refType) pElement->nonLinear = CFBooleanGetValue (refType); refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementHasPreferedStateKey)); if (refType) pElement->preferredState = CFBooleanGetValue (refType); refType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementHasNullStateKey)); if (refType) pElement->nullState = CFBooleanGetValue (refType); */ } /* examines CF dictionary vlaue in device element hierarchy to determine if it is element of interest or a collection of more elements * if element of interest allocate storage, add to list and retrieve element specific info * if collection then pass on to deconstruction collection into additional individual elements */ static void HIDAddElement (CFTypeRef refElement, recDevice* pDevice) { recElement* element = NULL; recElement** headElement = NULL; long elementType, usagePage, usage; CFTypeRef refElementType = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementTypeKey)); CFTypeRef refUsagePage = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementUsagePageKey)); CFTypeRef refUsage = CFDictionaryGetValue (refElement, CFSTR(kIOHIDElementUsageKey)); if ((refElementType) && (CFNumberGetValue (refElementType, kCFNumberLongType, &elementType))) { /* look at types of interest */ if ((elementType == kIOHIDElementTypeInput_Misc) || (elementType == kIOHIDElementTypeInput_Button) || (elementType == kIOHIDElementTypeInput_Axis)) { if (refUsagePage && CFNumberGetValue (refUsagePage, kCFNumberLongType, &usagePage) && refUsage && CFNumberGetValue (refUsage, kCFNumberLongType, &usage)) { switch (usagePage) /* only interested in kHIDPage_GenericDesktop and kHIDPage_Button */ { case kHIDPage_GenericDesktop: { switch (usage) /* look at usage to determine function */ { case kHIDUsage_GD_X: case kHIDUsage_GD_Y: case kHIDUsage_GD_Z: case kHIDUsage_GD_Rx: case kHIDUsage_GD_Ry: case kHIDUsage_GD_Rz: case kHIDUsage_GD_Slider: case kHIDUsage_GD_Dial: case kHIDUsage_GD_Wheel: element = (recElement *) NewPtrClear (sizeof (recElement)); if (element) { pDevice->axes++; headElement = &(pDevice->firstAxis); } break; case kHIDUsage_GD_Hatswitch: element = (recElement *) NewPtrClear (sizeof (recElement)); if (element) { pDevice->hats++; headElement = &(pDevice->firstHat); } break; } } break; case kHIDPage_Button: element = (recElement *) NewPtrClear (sizeof (recElement)); if (element) { pDevice->buttons++; headElement = &(pDevice->firstButton); } break; default: break; } } } else if (kIOHIDElementTypeCollection == elementType) HIDGetCollectionElements ((CFMutableDictionaryRef) refElement, pDevice); } if (element && headElement) /* add to list */ { pDevice->elements++; if (NULL == *headElement) *headElement = element; else { recElement *elementPrevious, *elementCurrent; elementCurrent = *headElement; while (elementCurrent) { elementPrevious = elementCurrent; elementCurrent = elementPrevious->pNext; } elementPrevious->pNext = element; } element->pNext = NULL; HIDGetElementInfo (refElement, element); } } /* collects information from each array member in device element list (each array memeber = element) */ static void HIDGetElementsCFArrayHandler (const void * value, void * parameter) { if (CFGetTypeID (value) == CFDictionaryGetTypeID ()) HIDAddElement ((CFTypeRef) value, (recDevice *) parameter); } /* handles retrieval of element information from arrays of elements in device IO registry information */ static void HIDGetElements (CFTypeRef refElementCurrent, recDevice *pDevice) { CFTypeID type = CFGetTypeID (refElementCurrent); if (type == CFArrayGetTypeID()) /* if element is an array */ { CFRange range = {0, CFArrayGetCount (refElementCurrent)}; /* CountElementsCFArrayHandler called for each array member */ CFArrayApplyFunction (refElementCurrent, range, HIDGetElementsCFArrayHandler, pDevice); } } /* handles extracting element information from element collection CF types * used from top level element decoding and hierarchy deconstruction to flatten device element list */ static void HIDGetCollectionElements (CFMutableDictionaryRef deviceProperties, recDevice *pDevice) { CFTypeRef refElementTop = CFDictionaryGetValue (deviceProperties, CFSTR(kIOHIDElementKey)); if (refElementTop) HIDGetElements (refElementTop, pDevice); } /* use top level element usage page and usage to discern device usage page and usage setting appropriate vlaues in device record */ static void HIDTopLevelElementHandler (const void * value, void * parameter) { CFTypeRef refCF = 0; if (CFGetTypeID (value) != CFDictionaryGetTypeID ()) return; refCF = CFDictionaryGetValue (value, CFSTR(kIOHIDElementUsagePageKey)); if (!CFNumberGetValue (refCF, kCFNumberLongType, &((recDevice *) parameter)->usagePage)) SDL_SetError ("CFNumberGetValue error retrieving pDevice->usagePage."); refCF = CFDictionaryGetValue (value, CFSTR(kIOHIDElementUsageKey)); if (!CFNumberGetValue (refCF, kCFNumberLongType, &((recDevice *) parameter)->usage)) SDL_SetError ("CFNumberGetValue error retrieving pDevice->usage."); } /* extracts device info from CF dictionary records in IO registry */ static void HIDGetDeviceInfo (io_object_t hidDevice, CFMutableDictionaryRef hidProperties, recDevice *pDevice) { CFMutableDictionaryRef usbProperties = 0; io_registry_entry_t parent1, parent2; /* Mac OS X currently is not mirroring all USB properties to HID page so need to look at USB device page also * get dictionary for usb properties: step up two levels and get CF dictionary for USB properties */ if ((KERN_SUCCESS == IORegistryEntryGetParentEntry (hidDevice, kIOServicePlane, &parent1)) && (KERN_SUCCESS == IORegistryEntryGetParentEntry (parent1, kIOServicePlane, &parent2)) && (KERN_SUCCESS == IORegistryEntryCreateCFProperties (parent2, &usbProperties, kCFAllocatorDefault, kNilOptions))) { if (usbProperties) { CFTypeRef refCF = 0; /* get device info * try hid dictionary first, if fail then go to usb dictionary */ /* get product name */ refCF = CFDictionaryGetValue (hidProperties, CFSTR(kIOHIDProductKey)); if (!refCF) refCF = CFDictionaryGetValue (usbProperties, CFSTR("USB Product Name")); if (refCF) { if (!CFStringGetCString (refCF, pDevice->product, 256, CFStringGetSystemEncoding ())) SDL_SetError ("CFStringGetCString error retrieving pDevice->product."); } /* get usage page and usage */ refCF = CFDictionaryGetValue (hidProperties, CFSTR(kIOHIDPrimaryUsagePageKey)); if (refCF) { if (!CFNumberGetValue (refCF, kCFNumberLongType, &pDevice->usagePage)) SDL_SetError ("CFNumberGetValue error retrieving pDevice->usagePage."); refCF = CFDictionaryGetValue (hidProperties, CFSTR(kIOHIDPrimaryUsageKey)); if (refCF) if (!CFNumberGetValue (refCF, kCFNumberLongType, &pDevice->usage)) SDL_SetError ("CFNumberGetValue error retrieving pDevice->usage."); } if (NULL == refCF) /* get top level element HID usage page or usage */ { /* use top level element instead */ CFTypeRef refCFTopElement = 0; refCFTopElement = CFDictionaryGetValue (hidProperties, CFSTR(kIOHIDElementKey)); { /* refCFTopElement points to an array of element dictionaries */ CFRange range = {0, CFArrayGetCount (refCFTopElement)}; CFArrayApplyFunction (refCFTopElement, range, HIDTopLevelElementHandler, pDevice); } } CFRelease (usbProperties); } else SDL_SetError ("IORegistryEntryCreateCFProperties failed to create usbProperties."); if (kIOReturnSuccess != IOObjectRelease (parent2)) SDL_SetError ("IOObjectRelease error with parent2."); if (kIOReturnSuccess != IOObjectRelease (parent1)) SDL_SetError ("IOObjectRelease error with parent1."); } } static recDevice *HIDBuildDevice (io_object_t hidDevice) { recDevice *pDevice = (recDevice *) NewPtrClear (sizeof (recDevice)); if (pDevice) { /* get dictionary for HID properties */ CFMutableDictionaryRef hidProperties = 0; kern_return_t result = IORegistryEntryCreateCFProperties (hidDevice, &hidProperties, kCFAllocatorDefault, kNilOptions); if ((result == KERN_SUCCESS) && hidProperties) { /* create device interface */ result = HIDCreateOpenDeviceInterface (hidDevice, pDevice); if (kIOReturnSuccess == result) { HIDGetDeviceInfo (hidDevice, hidProperties, pDevice); /* hidDevice used to find parents in registry tree */ HIDGetCollectionElements (hidProperties, pDevice); } else { DisposePtr((Ptr)pDevice); pDevice = NULL; } CFRelease (hidProperties); } else { DisposePtr((Ptr)pDevice); pDevice = NULL; } } return pDevice; } /* disposes of the element list associated with a device and the memory associated with the list */ static void HIDDisposeElementList (recElement **elementList) { recElement *pElement = *elementList; while (pElement) { recElement *pElementNext = pElement->pNext; DisposePtr ((Ptr) pElement); pElement = pElementNext; } *elementList = NULL; } /* disposes of a single device, closing and releaseing interface, freeing memory fro device and elements, setting device pointer to NULL * all your device no longer belong to us... (i.e., you do not 'own' the device anymore) */ static recDevice *HIDDisposeDevice (recDevice **ppDevice) { kern_return_t result = KERN_SUCCESS; recDevice *pDeviceNext = NULL; if (*ppDevice) { // save next device prior to disposing of this device pDeviceNext = (*ppDevice)->pNext; /* free element lists */ HIDDisposeElementList (&(*ppDevice)->firstAxis); HIDDisposeElementList (&(*ppDevice)->firstButton); HIDDisposeElementList (&(*ppDevice)->firstHat); result = HIDCloseReleaseInterface (*ppDevice); /* function sanity checks interface value (now application does not own device) */ if (kIOReturnSuccess != result) HIDReportErrorNum ("HIDCloseReleaseInterface failed when trying to dipose device.", result); DisposePtr ((Ptr)*ppDevice); *ppDevice = NULL; } return pDeviceNext; } /* Function to scan the system for joysticks. * Joystick 0 should be the system default joystick. * This function should return the number of available joysticks, or -1 * on an unrecoverable fatal error. */ int SDL_SYS_JoystickInit(void) { IOReturn result = kIOReturnSuccess; mach_port_t masterPort = 0; io_iterator_t hidObjectIterator = 0; CFMutableDictionaryRef hidMatchDictionary = NULL; recDevice *device, *lastDevice; io_object_t ioHIDDeviceObject = 0; SDL_numjoysticks = 0; if (!gpDeviceList) { SDL_SetError("Joystick: Device list already inited."); return -1; } result = IOMasterPort (bootstrap_port, &masterPort); if (kIOReturnSuccess != result) { SDL_SetError("Joystick: IOMasterPort error with bootstrap_port."); return -1; } /* Set up a matching dictionary to search I/O Registry by class name for all HID class devices. */ hidMatchDictionary = IOServiceMatching (kIOHIDDeviceKey); if (hidMatchDictionary) { /* Add key for device type (joystick, in this case) to refine the matching dictionary. */ /* NOTE: we now perform this filtering later UInt32 usagePage = kHIDPage_GenericDesktop; UInt32 usage = kHIDUsage_GD_Joystick; CFNumberRef refUsage = NULL, refUsagePage = NULL; refUsage = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &usage); CFDictionarySetValue (hidMatchDictionary, CFSTR (kIOHIDPrimaryUsageKey), refUsage); refUsagePage = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &usagePage); CFDictionarySetValue (hidMatchDictionary, CFSTR (kIOHIDPrimaryUsagePageKey), refUsagePage); */ } else { SDL_SetError("Joystick: Failed to get HID CFMutableDictionaryRef via IOServiceMatching."); return -1; } /*/ Now search I/O Registry for matching devices. */ result = IOServiceGetMatchingServices (masterPort, hidMatchDictionary, &hidObjectIterator); /* Check for errors */ if (kIOReturnSuccess != result) { SDL_SetError("Joystick: Couldn't create a HID object iterator."); return -1; } if (!hidObjectIterator) /* there are no joysticks */ { gpDeviceList = NULL; SDL_numjoysticks = 0; return 0; } /* IOServiceGetMatchingServices consumes a reference to the dictionary, so we don't need to release the dictionary ref. */ /* build flat linked list of devices from device iterator */ gpDeviceList = lastDevice = NULL; while ((ioHIDDeviceObject = IOIteratorNext (hidObjectIterator))) { /* build a device record */ device = HIDBuildDevice (ioHIDDeviceObject); if (!device) continue; /* dump device object, it is no longer needed */ result = IOObjectRelease (ioHIDDeviceObject); // if (KERN_SUCCESS != result) // HIDReportErrorNum ("IOObjectRelease error with ioHIDDeviceObject.", result); /* Filter device list to non-keyboard/mouse stuff */ if ( (device->usagePage != kHIDPage_GenericDesktop) || ((device->usage != kHIDUsage_GD_Joystick && device->usage != kHIDUsage_GD_GamePad)) ) { /* release memory for the device */ HIDDisposeDevice (&device); DisposePtr((Ptr)device); continue; } /* Add device to the end of the list */ if (lastDevice) lastDevice->pNext = device; else gpDeviceList = device; lastDevice = device; } result = IOObjectRelease (hidObjectIterator); /* release the iterator */ /* Count the total number of devices we found */ device = gpDeviceList; while (device) { SDL_numjoysticks++; device = device->pNext; } return SDL_numjoysticks; } /* Function to get the device-dependent name of a joystick */ const char *SDL_SYS_JoystickName(int index) { recDevice *device = gpDeviceList; for (; index > 0; index--) device = device->pNext; return device->product; } /* Function to open a joystick for use. * The joystick to open is specified by the index field of the joystick. * This should fill the nbuttons and naxes fields of the joystick structure. * It returns 0, or -1 if there is an error. */ int SDL_SYS_JoystickOpen(SDL_Joystick *joystick) { recDevice *device = gpDeviceList; int index; for (index = joystick->index; index > 0; index--) device = device->pNext; joystick->hwdata = device; joystick->name = device->product; joystick->naxes = device->axes; joystick->nhats = device->hats; joystick->nballs = 0; joystick->nbuttons = device->buttons; return 0; } /* Function to update the state of a joystick - called as a device poll. * This function shouldn't update the joystick structure directly, * but instead should call SDL_PrivateJoystick*() to deliver events * and update joystick device state. */ void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick) { recDevice *device = joystick->hwdata; recElement *element; SInt32 value; int i; if (device->removed) /* device was unplugged; ignore it. */ { if (device->uncentered) { device->uncentered = 0; /* Tell the app that everything is centered/unpressed... */ for (i = 0; i < device->axes; i++) SDL_PrivateJoystickAxis(joystick, i, 0); for (i = 0; i < device->buttons; i++) SDL_PrivateJoystickButton(joystick, i, 0); for (i = 0; i < device->hats; i++) SDL_PrivateJoystickHat(joystick, i, SDL_HAT_CENTERED); } return; } element = device->firstAxis; i = 0; while (element) { value = HIDScaledCalibratedValue(device, element, -32768, 32767); if ( value != joystick->axes[i] ) SDL_PrivateJoystickAxis(joystick, i, value); element = element->pNext; ++i; } element = device->firstButton; i = 0; while (element) { value = HIDGetElementValue(device, element); if (value > 1) /* handle pressure-sensitive buttons */ value = 1; if ( value != joystick->buttons[i] ) SDL_PrivateJoystickButton(joystick, i, value); element = element->pNext; ++i; } element = device->firstHat; i = 0; while (element) { Uint8 pos = 0; value = HIDGetElementValue(device, element); if (element->max == 3) /* 4 position hatswitch - scale up value */ value *= 2; else if (element->max != 7) /* Neither a 4 nor 8 positions - fall back to default position (centered) */ value = -1; switch(value) { case 0: pos = SDL_HAT_UP; break; case 1: pos = SDL_HAT_RIGHTUP; break; case 2: pos = SDL_HAT_RIGHT; break; case 3: pos = SDL_HAT_RIGHTDOWN; break; case 4: pos = SDL_HAT_DOWN; break; case 5: pos = SDL_HAT_LEFTDOWN; break; case 6: pos = SDL_HAT_LEFT; break; case 7: pos = SDL_HAT_LEFTUP; break; default: /* Every other value is mapped to center. We do that because some * joysticks use 8 and some 15 for this value, and apparently * there are even more variants out there - so we try to be generous. */ pos = SDL_HAT_CENTERED; break; } if ( pos != joystick->hats[i] ) SDL_PrivateJoystickHat(joystick, i, pos); element = element->pNext; ++i; } return; } /* Function to close a joystick after use */ void SDL_SYS_JoystickClose(SDL_Joystick *joystick) { /* Should we do anything here? */ return; } /* Function to perform any system-specific joystick related cleanup */ void SDL_SYS_JoystickQuit(void) { while (NULL != gpDeviceList) gpDeviceList = HIDDisposeDevice (&gpDeviceList); }