root/trunk/orca/gl/joystick.c

//============================================================================
//
// joystick.c
//
// Copyright (C) 2005 Karl Robillard
//
//============================================================================


#ifdef __linux__

#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <linux/joystick.h>
#include "gx.h"


enum JoystickValue    // joystick object
{
    JV_NAME = 2,
    JV_FD,
    JV_AXIS_COUNT,
    JV_BTN_COUNT,
    JV_INPUT
};


static int jsOpen( OValue* a1, OContext* ctx )
{
    char* dev;
    int fd;

    if( ! orIs( a1, OT_WORD ) )
        return 0;
    if( a1->word.atom != gEnv.atom_joystick )
        return 0;

    dev = getenv( "JOYSTICK_DEV" );
    if( ! dev )
        //dev = "/dev/js0";
        dev = "/dev/input/js0";

    fd = open( dev, O_RDONLY | O_NONBLOCK );
    if( fd >= 0 )
    {
        char buttons, axes;
        char name[80];
        OIndex i;
        OBlock* blk;
        OBlock* cblk;
        OValue* val;
        OValue* end;


        val = orLookupPath( OT_WORD, orInternAtom( "joystick-port", 13 ),
                            OR_LPATH_END );
        if( ! val )
            return 1;

        orCloneObject( &val->ctx, ctx );
        cblk = orBlockPtr( ctx->vblkN );

        ioctl( fd, JSIOCGAXES, &axes );
        ioctl( fd, JSIOCGBUTTONS, &buttons );
        ioctl( fd, JSIOCGNAME(sizeof(name)), &name );

        val = cblk->values + JV_FD;
        orSetTF( val, OT_INTEGER );
        orInt(val) = fd;

        i = orMakeCString( name, -1 );
        val = cblk->values + JV_NAME;
        orSetTF( val, OT_STRING );
        orSetSeries( val, i, 0 );

        val = cblk->values + JV_AXIS_COUNT;
        orSetTF( val, OT_INTEGER );
        orInt(val) = axes;

        val = cblk->values + JV_BTN_COUNT;
        orSetTF( val, OT_INTEGER );
        orInt(val) = buttons;

        blk = orMakeBlock( axes + buttons );
        blk->used = axes + buttons;
        val = blk->values;
        end = val + blk->used;
        while( val != end )
        {
            orSetTF( val, OT_INTEGER );
            orInt(val) = 0;
            ++val;
        }

        val = cblk->values + JV_INPUT;
        orSetTF( val, OT_BLOCK );
        orSetSeries( val, orBlockN(blk), 0 );
    }
    else
    {
        orErrorT( OR_ERROR_ACCESS, "cannot open device %s", dev );
    }

    return 1;
}


static void jsClose( OContext* ctx )
{
    OBlock* vblk;
    OValue* val;
    int fd;

    vblk = orBlockPtr( ctx->vblkN );
    val = vblk->values + JV_FD;
    if( orIs( val, OT_INTEGER ) )
    {
        fd = orInt(val);
        if( fd > -1 )
        {
            close( fd );
            orSetTF( val, OT_NONE );
        }
    }
}


/*
  Set 'input block values.
*/
static void jsRead( OContext* ctx, OValue* a1 )
{
    int events = 0;
    OBlock* vblk;
    OValue* val;

    vblk = orBlockPtr( ctx->vblkN );
    val = vblk->values + JV_FD;

    if( orIs( val, OT_INTEGER ) && (orInt(val) > -1) )
    {
        int axes;
        int fd;
        struct js_event je;
        OBlock* blk;

        fd = orInt(val);

        val = vblk->values + JV_AXIS_COUNT;
        axes = orInt(val);

        val = vblk->values + JV_INPUT;
        blk = orBLOCK(val);
        val = blk->values;

        while( read(fd, &je, sizeof(struct js_event)) > 0 )
        {
            if( je.type & JS_EVENT_BUTTON )
            {
                // je.value will be 0 or 1.

                val[ je.number + axes ].integer = je.value;
            }
            else if( je.type & JS_EVENT_AXIS )
            {
                // je.value will be -32767 to +32767.

                val[ je.number ].integer = je.value;
            }
            events = 1;
        }

        if( errno != EAGAIN )
            perror( "Joystick read" );
    }

    orResult( OT_LOGIC, events );
}


static void jsWrite( OContext* ctx, OValue* a1 )
{
    (void) ctx;
    (void) a1;
}


OPortDevice joystickPortDev =
{
    jsOpen,
    jsClose,
    jsRead,
    jsWrite
};


#endif


//EOF