src/joystick/darwin/SDL_sysjoystick.c
changeset 172 37e3ca9254c7
child 196 c4c4b221a5e5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/joystick/darwin/SDL_sysjoystick.c	Tue Sep 11 19:00:18 2001 +0000
@@ -0,0 +1,776 @@
+/*
+	SDL - Simple DirectMedia Layer
+	Copyright (C) 1997, 1998, 1999, 2000, 2001  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@devolution.com
+*/
+
+/* SDL joystick driver for Darwn / MacOS X, based on the IOKit HID API */
+/* Written 2001 by Max Horn */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <sys/errno.h>
+#include <sysexits.h>
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <IOKit/IOKitLib.h>
+#include <IOKit/IOCFPlugIn.h>
+#include <IOKit/IOUSBHIDParser.h>
+#include <IOKit/hid/IOHIDLib.h>
+#include <IOKit/hid/IOHIDKeys.h>
+#include <CoreFoundation/CoreFoundation.h>
+
+#include "SDL_error.h"
+#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;
+
+	struct recDevice* pNext;				// next device
+};
+typedef struct joystick_hwdata recDevice;
+
+
+/* Linked list of all available devices */
+static recDevice *gpDeviceList = NULL;
+
+
+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
+ */
+
+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 */
+
+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 */
+
+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;
+}
+
+/* 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
+ */
+
+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);
+	}
+	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)
+ */
+
+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:
+									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(pDevice);
+				pDevice = NULL;
+			}
+			CFRelease (hidProperties);
+		}
+		else
+		{
+			DisposePtr(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 = NULL;
+	io_iterator_t hidObjectIterator = NULL;
+	CFMutableDictionaryRef hidMatchDictionary = NULL;
+	recDevice *device, *lastDevice;
+	io_object_t ioHIDDeviceObject = NULL;
+	UInt32 usagePage = kHIDPage_GenericDesktop;
+	UInt32 usage = kHIDUsage_GD_Joystick; /* We probably also should check for gamepads? */
+	
+	SDL_numjoysticks = 0;
+	
+	if (NULL != 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 != NULL) && (usagePage) && (usage))
+	{
+		/* Add key for device type (joystick, in this case) to refine the matching dictionary. */
+		CFNumberRef refUsage = NULL, refUsagePage = NULL;
+
+		refUsage = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &usagePage);
+		CFDictionarySetValue (hidMatchDictionary, CFSTR (kIOHIDPrimaryUsageKey), refUsage);
+		refUsagePage = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &usage);
+		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) || (NULL == hidObjectIterator))
+	{
+		SDL_SetError("Joystick: Couldn't create a HID object iterator.");
+		return -1;
+	}
+	/* 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);
+		/* 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;
+	
+	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 != joystick->buttons[i] )
+			SDL_PrivateJoystickButton(joystick, i, value);
+		element = element->pNext;
+		++i;
+	}
+	
+	element = device->firstHat;
+	i = 0;
+	while (element)
+	{
+		Uint8 pos;
+
+		value = HIDGetElementValue(device, element);
+		switch(value)
+		{
+			case 0:
+				pos = SDL_HAT_CENTERED;
+				break;
+			case 1:
+				pos = SDL_HAT_UP;
+				break;
+			case 2:
+				pos = SDL_HAT_RIGHTUP;
+				break;
+			case 3:
+				pos = SDL_HAT_RIGHT;
+				break;
+			case 4:
+				pos = SDL_HAT_RIGHTDOWN;
+				break;
+			case 5:
+				pos = SDL_HAT_DOWN;
+				break;
+			case 6:
+				pos = SDL_HAT_LEFTDOWN;
+				break;
+			case 7:
+				pos = SDL_HAT_LEFT;
+				break;
+			case 8:
+				pos = SDL_HAT_LEFTUP;
+				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);
+}