//========================================================================
// GLFW - An OpenGL framework
// File: x11_joystick.c
// Platform: X11 (Unix)
// API version: 2.6
// WWW: http://glfw.sourceforge.net
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Camilla Berglund
//
// 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"
//========================================================================
// Note: Only Linux joystick input is supported at the moment. Other
// systems will behave as if there are no joysticks connected.
//========================================================================
#ifdef linux
#define _GLFW_USE_LINUX_JOYSTICKS
#endif // linux
//************************************************************************
//**** GLFW internal functions ****
//************************************************************************
#ifdef _GLFW_USE_LINUX_JOYSTICKS
//------------------------------------------------------------------------
// Here are the Linux joystick driver v1.x interface definitions that we
// use (we do not want to rely on <linux/joystick.h>):
//------------------------------------------------------------------------
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
// Joystick event types
#define JS_EVENT_BUTTON 0x01 /* button pressed/released */
#define JS_EVENT_AXIS 0x02 /* joystick moved */
#define JS_EVENT_INIT 0x80 /* initial state of device */
// Joystick event structure
struct js_event {
unsigned int time; /* (u32) event timestamp in milliseconds */
signed short value; /* (s16) value */
unsigned char type; /* (u8) event type */
unsigned char number; /* (u8) axis/button number */
};
// Joystick IOCTL commands
#define JSIOCGVERSION _IOR('j', 0x01, int) /* get driver version (u32) */
#define JSIOCGAXES _IOR('j', 0x11, char) /* get number of axes (u8) */
#define JSIOCGBUTTONS _IOR('j', 0x12, char) /* get number of buttons (u8) */
#endif // _GLFW_USE_LINUX_JOYSTICKS
//========================================================================
// _glfwInitJoysticks() - Initialize joystick interface
//========================================================================
void _glfwInitJoysticks( void )
{
#ifdef _GLFW_USE_LINUX_JOYSTICKS
int k, n, fd, joy_count;
char *joy_base_name, joy_dev_name[ 20 ];
int driver_version = 0x000800;
char ret_data;
#endif // _GLFW_USE_LINUX_JOYSTICKS
int i;
// Start by saying that there are no sticks
for( i = 0; i <= GLFW_JOYSTICK_LAST; ++ i )
{
_glfwJoy[ i ].Present = GL_FALSE;
}
#ifdef _GLFW_USE_LINUX_JOYSTICKS
// Try to open joysticks (nonblocking)
joy_count = 0;
for( k = 0; k <= 1 && joy_count <= GLFW_JOYSTICK_LAST; ++ k )
{
// Pick joystick base name
switch( k )
{
case 0:
joy_base_name = "/dev/input/js"; // USB sticks
break;
case 1:
joy_base_name = "/dev/js"; // "Legacy" sticks
break;
default:
continue; // (should never happen)
}
// Try to open a few of these sticks
for( i = 0; i <= 50 && joy_count <= GLFW_JOYSTICK_LAST; ++ i )
{
sprintf( joy_dev_name, "%s%d", joy_base_name, i );
fd = open( joy_dev_name, O_NONBLOCK );
if( fd != -1 )
{
// Remember fd
_glfwJoy[ joy_count ].fd = fd;
// Check that the joystick driver version is 1.0+
ioctl( fd, JSIOCGVERSION, &driver_version );
if( driver_version < 0x010000 )
{
// It's an old 0.x interface (we don't support it)
close( fd );
continue;
}
// Get number of joystick axes
ioctl( fd, JSIOCGAXES, &ret_data );
_glfwJoy[ joy_count ].NumAxes = (int) ret_data;
// Get number of joystick buttons
ioctl( fd, JSIOCGBUTTONS, &ret_data );
_glfwJoy[ joy_count ].NumButtons = (int) ret_data;
// Allocate memory for joystick state
_glfwJoy[ joy_count ].Axis =
(float *) malloc( sizeof(float) *
_glfwJoy[ joy_count ].NumAxes );
if( _glfwJoy[ joy_count ].Axis == NULL )
{
close( fd );
continue;
}
_glfwJoy[ joy_count ].Button =
(char *) malloc( sizeof(char) *
_glfwJoy[ joy_count ].NumButtons );
if( _glfwJoy[ joy_count ].Button == NULL )
{
free( _glfwJoy[ joy_count ].Axis );
close( fd );
continue;
}
// Clear joystick state
for( n = 0; n < _glfwJoy[ joy_count ].NumAxes; ++ n )
{
_glfwJoy[ joy_count ].Axis[ n ] = 0.0f;
}
for( n = 0; n < _glfwJoy[ joy_count ].NumButtons; ++ n )
{
_glfwJoy[ joy_count ].Button[ n ] = GLFW_RELEASE;
}
// The joystick is supported and connected
_glfwJoy[ joy_count ].Present = GL_TRUE;
joy_count ++;
}
}
}
#endif // _GLFW_USE_LINUX_JOYSTICKS
}
//========================================================================
// _glfwTerminateJoysticks() - Close all opened joystick handles
//========================================================================
void _glfwTerminateJoysticks( void )
{
#ifdef _GLFW_USE_LINUX_JOYSTICKS
int i;
// Close any opened joysticks
for( i = 0; i <= GLFW_JOYSTICK_LAST; ++ i )
{
if( _glfwJoy[ i ].Present )
{
close( _glfwJoy[ i ].fd );
free( _glfwJoy[ i ].Axis );
free( _glfwJoy[ i ].Button );
_glfwJoy[ i ].Present = GL_FALSE;
}
}
#endif // _GLFW_USE_LINUX_JOYSTICKS
}
//========================================================================
// _glfwPollJoystickEvents() - Empty joystick event queue
//========================================================================
static void _glfwPollJoystickEvents( void )
{
#ifdef _GLFW_USE_LINUX_JOYSTICKS
struct js_event e;
int i;
// Get joystick events for all GLFW joysticks
for( i = 0; i <= GLFW_JOYSTICK_LAST; ++ i )
{
// Is the stick present?
if( _glfwJoy[ i ].Present )
{
// Read all queued events (non-blocking)
while( read(_glfwJoy[i].fd, &e, sizeof(struct js_event)) > 0 )
{
// We don't care if it's an init event or not
e.type &= ~JS_EVENT_INIT;
// Check event type
switch( e.type )
{
case JS_EVENT_AXIS:
_glfwJoy[ i ].Axis[ e.number ] = (float) e.value /
32767.0f;
// We need to change the sign for the Y axes, so that
// positive = up/forward, according to the GLFW spec.
if( e.number & 1 )
{
_glfwJoy[ i ].Axis[ e.number ] =
-_glfwJoy[ i ].Axis[ e.number ];
}
break;
case JS_EVENT_BUTTON:
_glfwJoy[ i ].Button[ e.number ] =
e.value ? GLFW_PRESS : GLFW_RELEASE;
break;
default:
break;
}
}
}
}
#endif // _GLFW_USE_LINUX_JOYSTICKS
}
//************************************************************************
//**** Platform implementation functions ****
//************************************************************************
//========================================================================
// _glfwPlatformGetJoystickParam() - Determine joystick capabilities
//========================================================================
int _glfwPlatformGetJoystickParam( int joy, int param )
{
// Is joystick present?
if( !_glfwJoy[ joy ].Present )
{
return 0;
}
switch( param )
{
case GLFW_PRESENT:
return GL_TRUE;
case GLFW_AXES:
return _glfwJoy[ joy ].NumAxes;
case GLFW_BUTTONS:
return _glfwJoy[ joy ].NumButtons;
default:
break;
}
return 0;
}
//========================================================================
// _glfwPlatformGetJoystickPos() - Get joystick axis positions
//========================================================================
int _glfwPlatformGetJoystickPos( int joy, float *pos, int numaxes )
{
int i;
// Is joystick present?
if( !_glfwJoy[ joy ].Present )
{
return 0;
}
// Update joystick state
_glfwPollJoystickEvents();
// Does the joystick support less axes than requested?
if( _glfwJoy[ joy ].NumAxes < numaxes )
{
numaxes = _glfwJoy[ joy ].NumAxes;
}
// Copy axis positions from internal state
for( i = 0; i < numaxes; ++ i )
{
pos[ i ] = _glfwJoy[ joy ].Axis[ i ];
}
return numaxes;
}
//========================================================================
// _glfwPlatformGetJoystickButtons() - Get joystick button states
//========================================================================
int _glfwPlatformGetJoystickButtons( int joy, unsigned char *buttons,
int numbuttons )
{
int i;
// Is joystick present?
if( !_glfwJoy[ joy ].Present )
{
return 0;
}
// Update joystick state
_glfwPollJoystickEvents();
// Does the joystick support less buttons than requested?
if( _glfwJoy[ joy ].NumButtons < numbuttons )
{
numbuttons = _glfwJoy[ joy ].NumButtons;
}
// Copy button states from internal state
for( i = 0; i < numbuttons; ++ i )
{
buttons[ i ] = _glfwJoy[ joy ].Button[ i ];
}
return numbuttons;
}