/*

SDL - Simple DirectMedia Layer

Copyright (C) 2008 Edgar Simo

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 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

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

slouken@libsdl.org

*/

#include "SDL_config.h"

#ifdef SDL_HAPTIC_LINUX

#include "SDL_haptic.h"

#include "../SDL_syshaptic.h"

#include "SDL_joystick.h"

#include "../../joystick/SDL_sysjoystick.h" /* For the real SDL_Joystick */

#include "../../joystick/linux/SDL_sysjoystick_c.h" /* For joystick hwdata */

#include <unistd.h> /* close */

#include <linux/input.h>

#include <sys/ioctl.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <linux/limits.h>

#include <limits.h> /* INT_MAX */

#include <string.h>

#include <errno.h>

#include <math.h>

#ifndef M_PI

# define M_PI 3.14159265358979323846

#endif

#define MAX_HAPTICS 32

/*

* List of available haptic devices.

*/

static struct

{

char *fname;

SDL_Haptic *haptic;

} SDL_hapticlist[MAX_HAPTICS];

/*

* Haptic system hardware data.

*/

struct haptic_hwdata

};

/*

* Haptic system effect data.

*/

struct haptic_hweffect

{

struct ff_effect effect; /* The linux kernel effect structure. */

};

#define test_bit(nr, addr) \

(((1UL << ((nr) & 31)) & (((const unsigned int *) addr)[(nr) >> 5])) != 0)

#define EV_TEST(ev,f) \

if (test_bit((ev), features)) ret |= (f);

/*

* Test whether a device has haptic properties.

* Returns available properties or 0 if there are none.

*/

static int

EV_IsHaptic(int fd)

{

unsigned int ret;

unsigned long features[1 + FF_MAX/sizeof(unsigned long)];

/* Ask device for what it has. */

ret = 0;

if (ioctl(fd, EVIOCGBIT(EV_FF, sizeof(features)), features) < 0) {

SDL_SetError("Haptic: Unable to get device's features: %s", strerror(errno));

return -1;

}

/* Convert supported features to SDL_HAPTIC platform-neutral features. */

EV_TEST(FF_CONSTANT, SDL_HAPTIC_CONSTANT);

EV_TEST(FF_PERIODIC, SDL_HAPTIC_SINE |

SDL_HAPTIC_SQUARE |

SDL_HAPTIC_TRIANGLE |

SDL_HAPTIC_SAWTOOTHUP |

SDL_HAPTIC_SAWTOOTHDOWN);

EV_TEST(FF_RAMP, SDL_HAPTIC_RAMP);

EV_TEST(FF_SPRING, SDL_HAPTIC_SPRING);

EV_TEST(FF_FRICTION, SDL_HAPTIC_FRICTION);

EV_TEST(FF_DAMPER, SDL_HAPTIC_DAMPER);

EV_TEST(FF_INERTIA, SDL_HAPTIC_INERTIA);

EV_TEST(FF_CUSTOM, SDL_HAPTIC_CUSTOM);

EV_TEST(FF_GAIN, SDL_HAPTIC_GAIN);

EV_TEST(FF_AUTOCENTER, SDL_HAPTIC_AUTOCENTER);

/* Return what it supports. */

return ret;

}

/*

* Tests whether a device is a mouse or not.

*/

static int

EV_IsMouse(int fd)

{

unsigned long argp[40];

/* Ask for supported features. */

if (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(argp)), argp) < 0) {

return -1;

}

/* Currently we only test for BTN_MOUSE which can give fake positives. */

if (test_bit(BTN_MOUSE,argp) != 0) {

return 1;

}

return 0;

}

/*

* Initializes the haptic subsystem by finding available devices.

*/

int

SDL_SYS_HapticInit(void)

{

const char joydev_pattern[] = "/dev/input/event%d";

dev_t dev_nums[MAX_HAPTICS];

char path[PATH_MAX];

struct stat sb;

int fd;

int i, j, k;

int duplicate;

int numhaptics;

numhaptics = 0;

/*

* Limit amount of checks to MAX_HAPTICS since we may or may not have

* permission to some or all devices.

*/

i = 0;

for (j = 0; j < MAX_HAPTICS; ++j) {

snprintf(path, PATH_MAX, joydev_pattern, i++);

/* check to see if file exists */

if (stat(path,&sb) != 0)

break;

/* check for duplicates */

duplicate = 0;

for (k = 0; (k < numhaptics) && !duplicate; ++k) {

if (sb.st_rdev == dev_nums[k]) {

duplicate = 1;

}

}

if (duplicate) {

continue;

}

/* try to open */

fd = open(path, O_RDWR, 0);

if (fd < 0) continue;

#ifdef DEBUG_INPUT_EVENTS

printf("Checking %s\n", path);

#endif

/* see if it works */

if (EV_IsHaptic(fd) > 0) {

SDL_hapticlist[numhaptics].fname = SDL_strdup(path);

SDL_hapticlist[numhaptics].haptic = NULL;

dev_nums[numhaptics] = sb.st_rdev;

++numhaptics;

}

close(fd);

}

return numhaptics;

}

/*

* Gets the name from a file descriptor.

*/

static const char *

SDL_SYS_HapticNameFromFD(int fd)

{

static char namebuf[128];

/* We use the evdev name ioctl. */

if (ioctl(fd, EVIOCGNAME(sizeof(namebuf)), namebuf) <= 0) {

return NULL;

}

return namebuf;

}

/*

* Return the name of a haptic device, does not need to be opened.

*/

const char *

SDL_SYS_HapticName(int index)

{

int fd;

const char *name;

/* Open the haptic device. */

name = NULL;

fd = open(SDL_hapticlist[index].fname, O_RDONLY, 0);

if (fd >= 0) {

name = SDL_SYS_HapticNameFromFD(fd);

if (name==NULL) {

/* No name found, return device character device */

name = SDL_hapticlist[index].fname;

}

}

close(fd);

return name;

}

/*

* Opens the haptic device from the file descriptor.

*/

static int

SDL_SYS_HapticOpenFromFD(SDL_Haptic * haptic, int fd)

{

const char *name;

/* Allocate the hwdata */

haptic->hwdata = (struct haptic_hwdata *)

SDL_malloc(sizeof(*haptic->hwdata));

if (haptic->hwdata == NULL) {

SDL_OutOfMemory();

goto open_err;

}

SDL_memset(haptic->hwdata, 0, sizeof(*haptic->hwdata));

/* Set the data. */

haptic->hwdata->fd = fd;

haptic->supported = EV_IsHaptic(fd);

haptic->naxes = 2; /* Hardcoded for now, not sure if it's possible to find out. */

/* Set the effects */

if (ioctl(fd, EVIOCGEFFECTS, &haptic->neffects) < 0) {

SDL_SetError("Haptic: Unable to query device memory: %s", strerror(errno));

goto open_err;

}

haptic->nplaying = haptic->neffects; /* Linux makes no distinction. */

haptic->effects = (struct haptic_effect *)

SDL_malloc(sizeof(struct haptic_effect) * haptic->neffects);

if (haptic->effects == NULL) {

SDL_OutOfMemory();

goto open_err;

}

/* Clear the memory */

SDL_memset(haptic->effects, 0,

sizeof(struct haptic_effect) * haptic->neffects);

return 0;

/* Error handling */

open_err:

close(fd);

if (haptic->hwdata != NULL) {

free(haptic->hwdata);

haptic->hwdata = NULL;

}

return -1;

}

/*

* Opens a haptic device for usage.

*/

int

SDL_SYS_HapticOpen(SDL_Haptic * haptic)

{

int fd;

int ret;

/* Open the character device */

fd = open(SDL_hapticlist[haptic->index].fname, O_RDWR, 0);

if (fd < 0) {

SDL_SetError("Haptic: Unable to open %s: %s",

SDL_hapticlist[haptic->index], strerror(errno));

return -1;

}

/* Try to create the haptic. */

ret = SDL_SYS_HapticOpenFromFD(haptic,fd); /* Already closes on error. */

if (ret < 0) {

return -1;

}

/* Set the fname. */

haptic->hwdata->fname = SDL_hapticlist[haptic->index].fname;

return 0;

}

/*

* Opens a haptic device from first mouse it finds for usage.

*/

int

SDL_SYS_HapticMouse(void)

{

int fd;

int i;

for (i=0; i<SDL_numhaptics; i++) {

/* Open the device. */

fd = open(SDL_hapticlist[i].fname, O_RDWR, 0);

if (fd < 0) {

SDL_SetError("Haptic: Unable to open %s: %s",

SDL_hapticlist[i], strerror(errno));

return -1;

}

if (EV_IsMouse(fd)) {

close(fd);

return i;

}

close(fd);

}

return -1;

}

/*

* Checks to see if a joystick has haptic features.

*/

int

SDL_SYS_JoystickIsHaptic(SDL_Joystick * joystick)

{

return EV_IsHaptic(joystick->hwdata->fd);

}

/*

* Checks to see if the haptic device and joystick and in reality the same.

*/

int

SDL_SYS_JoystickSameHaptic(SDL_Haptic * haptic, SDL_Joystick * joystick)

{

/* We are assuming linux is using evdev which should trump the old

* joystick methods. */

if (SDL_strcmp(joystick->hwdata->fname,haptic->hwdata->fname)==0) {

return 1;

}

return 0;

}

/*

* Opens a SDL_Haptic from a SDL_Joystick.

*/

int

SDL_SYS_HapticOpenFromJoystick(SDL_Haptic * haptic, SDL_Joystick * joystick)

{

int i;

int fd;

int ret;

/* Find the joystick in the haptic list. */

for (i=0; i<MAX_HAPTICS; i++) {

if (SDL_hapticlist[i].fname != NULL) {

if (SDL_strcmp(SDL_hapticlist[i].fname, joystick->hwdata->fname)==0) {

haptic->index = i;

}

}

}

fd = open(joystick->hwdata->fname, O_RDWR, 0);

ret = SDL_SYS_HapticOpenFromFD(haptic,fd); /* Already closes on error. */

if (ret < 0) {

return -1;

}

haptic->hwdata->fname = SDL_hapticlist[haptic->index].fname;

return 0;

}

/*

* Closes the haptic device.

*/

void

SDL_SYS_HapticClose(SDL_Haptic * haptic)

{

if (haptic->hwdata) {

/* Clean up */

close(haptic->hwdata->fd);

/* Free */

SDL_free(haptic->hwdata);

SDL_free(haptic->effects);

}

/* Clear the rest. */

SDL_memset(haptic, 0, sizeof(SDL_Haptic));

}

/*

* Clean up after system specific haptic stuff

*/

void

SDL_SYS_HapticQuit(void)

{

int i;

for (i=0; SDL_hapticlist[i].fname != NULL; i++) {

/* Opened and not closed haptics are leaked, this is on purpose.

* Close your haptic devices after usage. */

SDL_free(SDL_hapticlist[i].fname);

}

SDL_hapticlist[0].fname = NULL;

}

/*

* Returns the ff_effect usable direction from a SDL_HapticDirection.

*/

static Uint16

SDL_SYS_ToDirection( SDL_HapticDirection * dir )

{

Uint32 tmp;

float f; /* Ideally we'd use fixed point math instead of floats... */

switch (dir->type) {

case SDL_HAPTIC_POLAR:

/* Linux directions are inverted. */

tmp = (((18000 + dir->dir[0]) % 36000) * 0xFFFF) / 36000;

return (Uint16) tmp;

case SDL_HAPTIC_CARTESIAN:

/* We must invert "x" and "y" to go clockwise. */

f = atan2(dir->dir[0], dir->dir[1]);

tmp = (int)(f*18000./M_PI) % 36000;

tmp = (tmp * 0xFFFF) / 36000;

return (Uint16) tmp;

case SDL_HAPTIC_SPHERICAL:

tmp = (36000 - dir->dir[0]) + 27000; /* Convert to polars */

tmp = (((18000 + tmp) % 36000) * 0xFFFF) / 36000;

return (Uint16) tmp;

default:

SDL_SetError("Haptic: Unsupported direction type.");

return -1;

}

return 0;

}

#define CLAMP(x) (((x) > 32767) ? 32767 : x)

/*

* Initializes the linux effect struct from a haptic_effect.

* Values above 32767 (for unsigned) are unspecified so we must clamp.

*/

static int

SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )

{

Uint32 tmp;

SDL_HapticConstant *constant;

SDL_HapticPeriodic *periodic;

SDL_HapticCondition *condition;

SDL_HapticRamp *ramp;

/* Clear up */

SDL_memset(dest, 0, sizeof(struct ff_effect));

switch (src->type) {

case SDL_HAPTIC_CONSTANT:

constant = &src->constant;

/* Header */

dest->type = FF_CONSTANT;

dest->direction = SDL_SYS_ToDirection(&constant->direction);

if (dest->direction < 0) return -1;

/* Replay */

dest->replay.length = (constant->length == SDL_HAPTIC_INFINITY) ?

0 : CLAMP(constant->length);

dest->replay.delay = CLAMP(constant->delay);

/* Trigger */

dest->trigger.button = CLAMP(constant->button);

dest->trigger.interval = CLAMP(constant->interval);

/* Constant */

dest->u.constant.level = constant->level;

/* Envelope */

dest->u.constant.envelope.attack_length = CLAMP(constant->attack_length);

dest->u.constant.envelope.attack_level = CLAMP(constant->attack_level);

dest->u.constant.envelope.fade_length = CLAMP(constant->fade_length);

dest->u.constant.envelope.fade_level = CLAMP(constant->fade_level);

break;

case SDL_HAPTIC_SINE:

case SDL_HAPTIC_SQUARE:

case SDL_HAPTIC_TRIANGLE:

case SDL_HAPTIC_SAWTOOTHUP:

case SDL_HAPTIC_SAWTOOTHDOWN:

periodic = &src->periodic;

/* Header */

dest->type = FF_PERIODIC;

dest->direction = SDL_SYS_ToDirection(&periodic->direction);

if (dest->direction < 0) return -1;

/* Replay */

dest->replay.length = (periodic->length == SDL_HAPTIC_INFINITY) ?

0 : CLAMP(periodic->length);

dest->replay.delay = CLAMP(periodic->delay);

/* Trigger */

dest->trigger.button = CLAMP(periodic->button);

dest->trigger.interval = CLAMP(periodic->interval);

/* Periodic */

if (periodic->type == SDL_HAPTIC_SINE)

dest->u.periodic.waveform = FF_SINE;

else if (periodic->type == SDL_HAPTIC_SQUARE)

dest->u.periodic.waveform = FF_SQUARE;

else if (periodic->type == SDL_HAPTIC_TRIANGLE)

dest->u.periodic.waveform = FF_TRIANGLE;

else if (periodic->type == SDL_HAPTIC_SAWTOOTHUP)

dest->u.periodic.waveform = FF_SAW_UP;

else if (periodic->type == SDL_HAPTIC_SAWTOOTHDOWN)

dest->u.periodic.waveform = FF_SAW_DOWN;

dest->u.periodic.period = CLAMP(periodic->period);

dest->u.periodic.magnitude = periodic->magnitude;

dest->u.periodic.offset = periodic->offset;

/* Phase is calculated based of offset from period and then clamped. */

tmp = ((periodic->phase % 36000) * dest->u.periodic.period) / 36000;

dest->u.periodic.phase = CLAMP(tmp);

/* Envelope */

dest->u.periodic.envelope.attack_length = CLAMP(periodic->attack_length);

dest->u.periodic.envelope.attack_level = CLAMP(periodic->attack_level);

dest->u.periodic.envelope.fade_length = CLAMP(periodic->fade_length);

dest->u.periodic.envelope.fade_level = CLAMP(periodic->fade_level);

break;

case SDL_HAPTIC_SPRING:

case SDL_HAPTIC_DAMPER:

case SDL_HAPTIC_INERTIA:

case SDL_HAPTIC_FRICTION:

condition = &src->condition;

/* Header */

if (condition->type == SDL_HAPTIC_SPRING)

dest->type = FF_SPRING;

else if (condition->type == SDL_HAPTIC_DAMPER)

dest->type = FF_DAMPER;

else if (condition->type == SDL_HAPTIC_INERTIA)

dest->type = FF_INERTIA;

else if (condition->type == SDL_HAPTIC_FRICTION)

dest->type = FF_FRICTION;

dest->direction = 0; /* Handled by the condition-specifics. */

/* Replay */

dest->replay.length = (condition->length == SDL_HAPTIC_INFINITY) ?

0 : CLAMP(condition->length);

dest->replay.delay = CLAMP(condition->delay);

/* Trigger */

dest->trigger.button = CLAMP(condition->button);

dest->trigger.interval = CLAMP(condition->interval);

/* Condition */

/* X axis */

dest->u.condition[0].right_saturation = CLAMP(condition->right_sat[0]);

dest->u.condition[0].left_saturation = CLAMP(condition->left_sat[0]);

dest->u.condition[0].right_coeff = condition->right_coeff[0];

dest->u.condition[0].left_coeff = condition->left_coeff[0];

dest->u.condition[0].deadband = CLAMP(condition->deadband[0]);

dest->u.condition[0].center = condition->center[0];

/* Y axis */

dest->u.condition[1].right_saturation = CLAMP(condition->right_sat[1]);

dest->u.condition[1].left_saturation = CLAMP(condition->left_sat[1]);

dest->u.condition[1].right_coeff = condition->right_coeff[1];

dest->u.condition[1].left_coeff = condition->left_coeff[1];

dest->u.condition[1].deadband = CLAMP(condition->deadband[1]);

dest->u.condition[1].center = condition->center[1];

break;

case SDL_HAPTIC_RAMP:

ramp = &src->ramp;

/* Header */

dest->type = FF_RAMP;

dest->direction = SDL_SYS_ToDirection(&ramp->direction);

if (dest->direction < 0) return -1;

/* Replay */

dest->replay.length = (ramp->length == SDL_HAPTIC_INFINITY) ?

0 : CLAMP(ramp->length);

dest->replay.delay = CLAMP(ramp->delay);

/* Trigger */

dest->trigger.button = CLAMP(ramp->button);

dest->trigger.interval = CLAMP(ramp->interval);

/* Ramp */

dest->u.ramp.start_level = ramp->start;

dest->u.ramp.end_level = ramp->end;

/* Envelope */

dest->u.ramp.envelope.attack_length = CLAMP(ramp->attack_length);

dest->u.ramp.envelope.attack_level = CLAMP(ramp->attack_level);

dest->u.ramp.envelope.fade_length = CLAMP(ramp->fade_length);

dest->u.ramp.envelope.fade_level = CLAMP(ramp->fade_level);

break;

default:

SDL_SetError("Haptic: Unknown effect type.");

return -1;

}

return 0;

}

/*

* Creates a new haptic effect.

*/

int

SDL_SYS_HapticNewEffect(SDL_Haptic * haptic, struct haptic_effect * effect,

SDL_HapticEffect * base)

{

struct ff_effect * linux_effect;

/* Allocate the hardware effect */

effect->hweffect = (struct haptic_hweffect *)

SDL_malloc(sizeof(struct haptic_hweffect));

if (effect->hweffect == NULL) {

SDL_OutOfMemory();

return -1;

}

/* Prepare the ff_effect */

linux_effect = &effect->hweffect->effect;

if (SDL_SYS_ToFFEffect( linux_effect, base ) != 0) {

goto new_effect_err;

}

linux_effect->id = -1; /* Have the kernel give it an id */

/* Upload the effect */

if (ioctl(haptic->hwdata->fd, EVIOCSFF, linux_effect) < 0) {

SDL_SetError("Haptic: Error uploading effect to the device: %s", strerror(errno));

goto new_effect_err;

}

return 0;

new_effect_err:

free(effect->hweffect);

effect->hweffect = NULL;

return -1;

}

/*

* Updates an effect.

*

* Note: Dynamically updating the direction can in some cases force

* the effect to restart and run once.

*/

int SDL_SYS_HapticUpdateEffect(SDL_Haptic * haptic,

struct haptic_effect * effect, SDL_HapticEffect * data)

{

struct ff_effect linux_effect;

/* Create the new effect */

if (SDL_SYS_ToFFEffect( &linux_effect, data ) != 0) {

return -1;

}

linux_effect.id = effect->hweffect->effect.id;

/* See if it can be uploaded. */

if (ioctl(haptic->hwdata->fd, EVIOCSFF, &linux_effect) < 0) {

SDL_SetError("Haptic: Error updating the effect: %s", strerror(errno));

return -1;

}

/* Copy the new effect into memory. */

SDL_memcpy( &effect->hweffect->effect, &linux_effect, sizeof(struct ff_effect) );

return effect->hweffect->effect.id;

}

/*

* Runs an effect.

*/

int

SDL_SYS_HapticRunEffect(SDL_Haptic * haptic, struct haptic_effect * effect,

Uint32 iterations)

{

struct input_event run;

/* Prepare to run the effect */

run.type = EV_FF;

run.code = effect->hweffect->effect.id;

/* We don't actually have infinity here, so we just do INT_MAX which is pretty damn close. */

run.value = (iterations > INT_MAX) ? INT_MAX : iterations;

if (write(haptic->hwdata->fd, (const void*) &run, sizeof(run)) < 0) {

SDL_SetError("Haptic: Unable to run the effect: %s", strerror(errno));

return -1;

}

return 0;

}

/*

* Stops an effect.

*/

int

SDL_SYS_HapticStopEffect(SDL_Haptic * haptic, struct haptic_effect * effect)

{

struct input_event stop;

stop.type = EV_FF;

stop.code = effect->hweffect->effect.id;

stop.value = 0;

if (write(haptic->hwdata->fd, (const void*) &stop, sizeof(stop)) < 0) {

SDL_SetError("Haptic: Unable to stop the effect: %s", strerror(errno));

return -1;

}

return 0;

}

/*

* Frees the effect.

*/

void

SDL_SYS_HapticDestroyEffect(SDL_Haptic * haptic, struct haptic_effect * effect)

{

if (ioctl(haptic->hwdata->fd, EVIOCRMFF, effect->hweffect->effect.id) < 0) {

SDL_SetError("Haptic: Error removing the effect from the device: %s",

strerror(errno));

}

SDL_free(effect->hweffect);

effect->hweffect = NULL;

}

/*

* Gets the status of a haptic effect.

*/

int

SDL_SYS_HapticGetEffectStatus(SDL_Haptic * haptic, struct haptic_effect * effect)

{

#if 0 /* Not supported atm. */

struct input_event ie;

ie.type = EV_FF;

ie.type = EV_FF_STATUS;

ie.code = effect->hweffect->effect.id;

if (write(haptic->hwdata->fd, &ie, sizeof(ie)) < 0) {

SDL_SetError("Haptic: Error getting device status.");

return -1;

}

return 0;

#endif

return -1;

}

/*

* Sets the gain.

*/

int

SDL_SYS_HapticSetGain(SDL_Haptic * haptic, int gain)

{

struct input_event ie;

ie.type = EV_FF;

ie.code = FF_GAIN;

ie.value = (0xFFFFUL * gain) / 100;

if (write(haptic->hwdata->fd, &ie, sizeof(ie)) < 0) {

SDL_SetError("Haptic: Error setting gain: %s", strerror(errno));

return -1;

}

return 0;

}

/*

* Sets the autocentering.

*/

int

SDL_SYS_HapticSetAutocenter(SDL_Haptic * haptic, int autocenter)

{

struct input_event ie;

ie.type = EV_FF;

ie.code = FF_AUTOCENTER;

ie.value = (0xFFFFUL * autocenter) / 100;

if (write(haptic->hwdata->fd, &ie, sizeof(ie)) < 0) {

SDL_SetError("Haptic: Error setting autocenter: %s", strerror(errno));

return -1;

}

return 0;

}

#endif /* SDL_HAPTIC_LINUX */