cocoa_joystick.m

//========================================================================
// GLFW - An OpenGL framework
// Platform:    Cocoa/NSOpenGL
// API Version: 2.7
// WWW:         http://www.glfw.org/
//------------------------------------------------------------------------
// Copyright (c) 2009-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================

#include "internal.h"

#include <unistd.h>
#include <ctype.h>

#include <mach/mach.h>
#include <mach/mach_error.h>

#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/IOCFPlugIn.h>
#include <IOKit/hid/IOHIDLib.h>
#include <IOKit/hid/IOHIDKeys.h>
#include <Kernel/IOKit/hidsystem/IOHIDUsageTables.h>


//------------------------------------------------------------------------
// Joystick state
//------------------------------------------------------------------------

typedef struct
{
    int present;
    char product[256];

    IOHIDDeviceInterface** interface;

    int numAxes;
    int numButtons;
    int numHats;

    CFMutableArrayRef axes;
    CFMutableArrayRef buttons;
    CFMutableArrayRef hats;

} _glfwJoystick;

static _glfwJoystick _glfwJoysticks[GLFW_JOYSTICK_LAST + 1];


typedef struct
{
    IOHIDElementCookie cookie;

    long value;

    long min;
    long max;

    long minReport;
    long maxReport;

} _glfwJoystickElement;


void GetElementsCFArrayHandler( const void* value, void* parameter );


//========================================================================
// Adds an element to the specified joystick
//========================================================================

static void addJoystickElement( _glfwJoystick* joystick, CFTypeRef refElement )
{
    long elementType, usagePage, usage;
    CFTypeRef refElementType, refUsagePage, refUsage;

    refElementType = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementTypeKey ) );
    refUsagePage = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementUsagePageKey ) );
    refUsage = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementUsageKey ) );

    CFMutableArrayRef elementsArray = NULL;

    CFNumberGetValue( refElementType, kCFNumberLongType, &elementType );
    CFNumberGetValue( refUsagePage, kCFNumberLongType, &usagePage );
    CFNumberGetValue( refUsage, kCFNumberLongType, &usage );

    if( elementType == kIOHIDElementTypeInput_Axis ||
        elementType == kIOHIDElementTypeInput_Button ||
        elementType == kIOHIDElementTypeInput_Misc )
    {
        switch( usagePage ) /* only interested in kHIDPage_GenericDesktop and kHIDPage_Button */
        {
            case kHIDPage_GenericDesktop:
            {
                switch( usage )
                {
                    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:
                        joystick->numAxes++;
                        elementsArray = joystick->axes;
                        break;
                    case kHIDUsage_GD_Hatswitch:
                        joystick->numHats++;
                        elementsArray = joystick->hats;
                        break;
                }

                break;
            }

            case kHIDPage_Button:
                joystick->numButtons++;
                elementsArray = joystick->buttons;
                break;
            default:
                break;
        }

        if( elementsArray )
        {
            long number;
            CFTypeRef refType;

            _glfwJoystickElement* element = (_glfwJoystickElement*) malloc( sizeof( _glfwJoystickElement ) );

            CFArrayAppendValue( elementsArray, element );

            refType = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementCookieKey ) );
            if( refType && CFNumberGetValue( refType, kCFNumberLongType, &number ) )
            {
                element->cookie = (IOHIDElementCookie) number;
            }

            refType = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementMinKey ) );
            if( refType && CFNumberGetValue( refType, kCFNumberLongType, &number ) )
            {
                element->minReport = element->min = number;
            }

            refType = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementMaxKey ) );
            if( refType && CFNumberGetValue( refType, kCFNumberLongType, &number ) )
            {
                element->maxReport = element->max = number;
            }
        }
    }
    else
    {
        CFTypeRef refElementTop = CFDictionaryGetValue( refElement, CFSTR( kIOHIDElementKey ) );
        if( refElementTop )
        {
            CFTypeID type = CFGetTypeID( refElementTop );
            if( type == CFArrayGetTypeID() ) /* if element is an array */
            {
                CFRange range = { 0, CFArrayGetCount( refElementTop ) };
                CFArrayApplyFunction( refElementTop, range, GetElementsCFArrayHandler, joystick );
            }
        }
    }
}


//========================================================================
// Adds an element to the specified joystick
//========================================================================

void GetElementsCFArrayHandler( const void* value, void* parameter )
{
    if( CFGetTypeID( value ) == CFDictionaryGetTypeID() )
    {
        addJoystickElement( (_glfwJoystick*) parameter, (CFTypeRef) value );
    }
}


//========================================================================
// Returns the value of the specified element of the specified joystick
//========================================================================

static long getElementValue( _glfwJoystick* joystick, _glfwJoystickElement* element )
{
    IOReturn result = kIOReturnSuccess;
    IOHIDEventStruct hidEvent;
    hidEvent.value = 0;

    if( joystick && element && joystick->interface )
    {
        result = (*(joystick->interface))->getElementValue( joystick->interface,
                                                            element->cookie,
                                                            &hidEvent );
        if( kIOReturnSuccess == result )
        {
            /* record min and max for auto calibration */
            if( hidEvent.value < element->minReport )
            {
                element->minReport = hidEvent.value;
            }
            if( hidEvent.value > element->maxReport )
            {
                element->maxReport = hidEvent.value;
            }
        }
    }

    /* auto user scale */
    return (long) hidEvent.value;
}


//========================================================================
// Removes the specified joystick
//========================================================================

static void removeJoystick( _glfwJoystick* joystick )
{
    int i;

    if( joystick->present )
    {
        joystick->present = GL_FALSE;

        for( i = 0;  i < joystick->numAxes;  i++ )
        {
            _glfwJoystickElement* axes =
                (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->axes, i );
            free( axes );
        }
        CFArrayRemoveAllValues( joystick->axes );
        joystick->numAxes = 0;

        for( i = 0;  i < joystick->numButtons;  i++ )
        {
            _glfwJoystickElement* button =
                (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->buttons, i );
            free( button );
        }
        CFArrayRemoveAllValues( joystick->buttons );
        joystick->numButtons = 0;

        for( i = 0;  i < joystick->numHats;  i++ )
        {
            _glfwJoystickElement* hat =
                (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->hats, i );
            free( hat );
        }
        CFArrayRemoveAllValues( joystick->hats );
        joystick->hats = 0;

        (*(joystick->interface))->close( joystick->interface );
        (*(joystick->interface))->Release( joystick->interface );

        joystick->interface = NULL;
    }
}


//========================================================================
// Callback for user-initiated joystick removal
//========================================================================

static void removalCallback( void* target, IOReturn result, void* refcon, void* sender )
{
    removeJoystick( (_glfwJoystick*) refcon );
}


//========================================================================
// Polls for joystick events and updates GFLW state
//========================================================================

static void pollJoystickEvents( void )
{
    int i;
    CFIndex j;

    for( i = 0;  i < GLFW_JOYSTICK_LAST + 1;  i++ )
    {
        _glfwJoystick* joystick = &_glfwJoysticks[i];

        if( joystick->present )
        {
            for( j = 0;  j < joystick->numButtons;  j++ )
            {
                _glfwJoystickElement* button =
                    (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->buttons, j );
                button->value = getElementValue( joystick, button );
            }

            for( j = 0;  j < joystick->numAxes;  j++ )
            {
                _glfwJoystickElement* axes =
                    (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->axes, j );
                axes->value = getElementValue( joystick, axes );
            }

            for( j = 0;  j < joystick->numHats;  j++ )
            {
                _glfwJoystickElement* hat =
                    (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick->hats, j );
                hat->value = getElementValue( joystick, hat );
            }
        }
    }
}


//************************************************************************
//****                  GLFW internal functions                       ****
//************************************************************************

//========================================================================
// Initialize joystick interface
//========================================================================

void _glfwInitJoysticks( void )
{
    int deviceCounter = 0;
    IOReturn result = kIOReturnSuccess;
    mach_port_t masterPort = 0;
    io_iterator_t objectIterator = 0;
    CFMutableDictionaryRef hidMatchDictionary = NULL;
    io_object_t ioHIDDeviceObject = 0;

    result = IOMasterPort( bootstrap_port, &masterPort );
    hidMatchDictionary = IOServiceMatching( kIOHIDDeviceKey );
    if( kIOReturnSuccess != result || !hidMatchDictionary )
    {
        if( hidMatchDictionary )
        {
            CFRelease( hidMatchDictionary );
        }

        return;
    }

    result = IOServiceGetMatchingServices( masterPort,
                                           hidMatchDictionary,
                                           &objectIterator );
    if( result != kIOReturnSuccess )
    {
        return;
    }

    if( !objectIterator ) /* there are no joysticks */
    {
        return;
    }

    while( ( ioHIDDeviceObject = IOIteratorNext( objectIterator ) ) )
    {
        CFMutableDictionaryRef hidProperties = 0;
        kern_return_t result;
        CFTypeRef refCF = 0;

        IOCFPlugInInterface** ppPlugInInterface = NULL;
        HRESULT plugInResult = S_OK;
        SInt32 score = 0;

        long usagePage, usage;

        result = IORegistryEntryCreateCFProperties( ioHIDDeviceObject,
                                                    &hidProperties,
                                                    kCFAllocatorDefault,
                                                    kNilOptions );

        if( result != kIOReturnSuccess )
        {
            continue;
        }

        /* Check device type */
        refCF = CFDictionaryGetValue( hidProperties, CFSTR( kIOHIDPrimaryUsagePageKey ) );
        if( refCF )
        {
            CFNumberGetValue( refCF, kCFNumberLongType, &usagePage );
            if( usagePage != kHIDPage_GenericDesktop )
            {
                /* We are not interested in this device */
                continue;
            }
        }

        refCF = CFDictionaryGetValue( hidProperties, CFSTR( kIOHIDPrimaryUsageKey ) );
        if( refCF )
        {
            CFNumberGetValue( refCF, kCFNumberLongType, &usage );

            if( usage != kHIDUsage_GD_Joystick &&
                usage != kHIDUsage_GD_GamePad &&
                usage != kHIDUsage_GD_MultiAxisController )
            {
                /* We are not interested in this device */
                continue;
            }
        }

        _glfwJoystick* joystick = &_glfwJoysticks[deviceCounter];

        joystick->present = GL_TRUE;

        result = IOCreatePlugInInterfaceForService( ioHIDDeviceObject,
                                                    kIOHIDDeviceUserClientTypeID,
                                                    kIOCFPlugInInterfaceID,
                                                    &ppPlugInInterface,
                                                    &score );

        if( kIOReturnSuccess != result )
        {
            return;
        }

        plugInResult = (*ppPlugInInterface)->QueryInterface( ppPlugInInterface,
                                                             CFUUIDGetUUIDBytes( kIOHIDDeviceInterfaceID ),
                                                             (void *) &(joystick->interface) );

        if( plugInResult != S_OK )
        {
            return;
        }

        (*ppPlugInInterface)->Release( ppPlugInInterface );

        (*(joystick->interface))->open( joystick->interface, 0 );
        (*(joystick->interface))->setRemovalCallback( joystick->interface,
                                                      removalCallback,
                                                      joystick,
                                                      joystick );

        /* Get product string */
        refCF = CFDictionaryGetValue( hidProperties, CFSTR( kIOHIDProductKey ) );
        if( refCF )
        {
            CFStringGetCString( refCF,
                                (char*) &(joystick->product),
                                256,
                                CFStringGetSystemEncoding() );
        }

        joystick->numAxes = 0;
        joystick->numButtons = 0;
        joystick->numHats = 0;
        joystick->axes = CFArrayCreateMutable( NULL, 0, NULL );
        joystick->buttons = CFArrayCreateMutable( NULL, 0, NULL );
        joystick->hats = CFArrayCreateMutable( NULL, 0, NULL );

        CFTypeRef refTopElement = CFDictionaryGetValue( hidProperties,
                                                        CFSTR( kIOHIDElementKey ) );
        CFTypeID type = CFGetTypeID( refTopElement );
        if( type == CFArrayGetTypeID() )
        {
            CFRange range = { 0, CFArrayGetCount( refTopElement ) };
            CFArrayApplyFunction( refTopElement,
                                  range,
                                  GetElementsCFArrayHandler,
                                  (void*) joystick);
        }

        deviceCounter++;
    }
}


//========================================================================
// Close all opened joystick handles
//========================================================================

void _glfwTerminateJoysticks( void )
{
    int i;

    for( i = 0;  i < GLFW_JOYSTICK_LAST + 1;  i++ )
    {
        _glfwJoystick* joystick = &_glfwJoysticks[i];
        removeJoystick( joystick );
    }
}


//************************************************************************
//****               Platform implementation functions                ****
//************************************************************************

//========================================================================
// Determine joystick capabilities
//========================================================================

int _glfwPlatformGetJoystickParam( int joy, int param )
{
    if( !_glfwJoysticks[joy].present )
    {
        // TODO: Figure out if this is an error
        return GL_FALSE;
    }

    switch( param )
    {
        case GLFW_PRESENT:
            return GL_TRUE;

        case GLFW_AXES:
            return (int) CFArrayGetCount( _glfwJoysticks[joy].axes );

        case GLFW_BUTTONS:
            return (int) CFArrayGetCount( _glfwJoysticks[joy].buttons ) +
                   ((int) CFArrayGetCount( _glfwJoysticks[joy].hats )) * 4;

        default:
            break;
    }

    return GL_FALSE;
}


//========================================================================
// Get joystick axis positions
//========================================================================

int _glfwPlatformGetJoystickPos( int joy, float *pos, int numaxes )
{
    int i;

    if( joy < GLFW_JOYSTICK_1 || joy > GLFW_JOYSTICK_LAST )
    {
        return 0;
    }

    _glfwJoystick joystick = _glfwJoysticks[joy];

    if( !joystick.present )
    {
        // TODO: Figure out if this is an error
        return 0;
    }

    numaxes = numaxes < joystick.numAxes ? numaxes : joystick.numAxes;

    // Update joystick state
    pollJoystickEvents();

    for( i = 0;  i < numaxes;  i++ )
    {
        _glfwJoystickElement* axes =
            (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick.axes, i );

        long readScale = axes->maxReport - axes->minReport;

        if( readScale == 0 )
        {
            pos[i] = axes->value;
        }
        else
        {
            pos[i] = (2.0f * (axes->value - axes->minReport) / readScale) - 1.0f;
        }

        //printf("%ld, %ld, %ld\n", axes->value, axes->minReport, axes->maxReport);

        if( i & 1 )
        {
            pos[i] = -pos[i];
        }
    }

    return numaxes;
}


//========================================================================
// Get joystick button states
//========================================================================

int _glfwPlatformGetJoystickButtons( int joy, unsigned char *buttons, int numbuttons )
{
    int i, j, button;

    if( joy < GLFW_JOYSTICK_1 || joy > GLFW_JOYSTICK_LAST )
    {
        return 0;
    }

    _glfwJoystick joystick = _glfwJoysticks[joy];

    if( !joystick.present )
    {
        // TODO: Figure out if this is an error
        return 0;
    }

    // Update joystick state
    pollJoystickEvents();

    for( button = 0;  button < numbuttons && button < joystick.numButtons;  button++ )
    {
        _glfwJoystickElement* element = (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick.buttons, button );
        buttons[button] = element->value ? GLFW_PRESS : GLFW_RELEASE;
    }

    // Virtual buttons - Inject data from hats
    // Each hat is exposed as 4 buttons which exposes 8 directions with concurrent button presses

    const int directions[9] = { 1, 3, 2, 6, 4, 12, 8, 9, 0 }; // Bit fields of button presses for each direction, including nil

    for( i = 0;  i < joystick.numHats;  i++ )
    {
        _glfwJoystickElement* hat = (_glfwJoystickElement*) CFArrayGetValueAtIndex( joystick.hats, i );
        int value = hat->value;
        if( value < 0 || value > 8 )
        {
            value = 8;
        }

        for( j = 0;  j < 4 && button < numbuttons;  j++ )
        {
            buttons[button++] = directions[value] & (1 << j) ? GLFW_PRESS : GLFW_RELEASE;
        }
    }

    return button;
}