src/haptic/SDL_haptic.c
author Edgar Simo <bobbens@gmail.com>
Mon, 30 Jun 2008 16:48:16 +0000
branchgsoc2008_force_feedback
changeset 2477 97f75ea43a93
parent 2476 242d8a668ebb
child 2478 4fd783e0f34b
permissions -rw-r--r--
Starting to add infrastructure to handle haptic effects.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 2008 Edgar Simo
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 #include "SDL_config.h"
    23 
    24 #include "SDL_haptic_c.h"
    25 #include "SDL_syshaptic.h"
    26 
    27 
    28 static Uint8 SDL_numhaptics = 0;
    29 SDL_Haptic **SDL_haptics = NULL;
    30 static SDL_Haptic *default_haptic = NULL;
    31 
    32 
    33 /*
    34  * Initializes the Haptic devices.
    35  */
    36 int
    37 SDL_HapticInit(void)
    38 {  
    39    int arraylen;
    40    int status;
    41 
    42    SDL_numhaptics = 0;
    43    status = SDL_SYS_HapticInit();
    44    if (status >= 0) {
    45       arraylen = (status + 1) * sizeof(*SDL_haptics);
    46       SDL_haptics = (SDL_Haptic **) SDL_malloc(arraylen);
    47       if (SDL_haptics == NULL) {
    48          SDL_numhaptics = 0;
    49       } else {
    50          SDL_memset(SDL_haptics, 0, arraylen);
    51          SDL_numhaptics = status;
    52       }
    53       status = 0;
    54    }
    55    default_haptic = NULL;
    56 
    57    return status;
    58 }
    59 
    60 
    61 /*
    62  * Returns the number of available devices.
    63  */
    64 int
    65 SDL_NumHaptics(void)
    66 {
    67    return SDL_numhaptics;
    68 }
    69 
    70 
    71 /*
    72  * Gets the name of a Haptic device by index.
    73  */
    74 const char *
    75 SDL_HapticName(int device_index)
    76 {
    77    if ((device_index < 0) || (device_index >= SDL_numhaptics)) {
    78       SDL_SetError("There are %d haptic devices available", SDL_numhaptics);
    79       return NULL;
    80    }
    81    return SDL_SYS_HapticName(device_index);
    82 }
    83 
    84 
    85 /*
    86  * Opens a Haptic device.
    87  */
    88 SDL_Haptic *
    89 SDL_HapticOpen(int device_index)
    90 {
    91    int i;
    92    SDL_Haptic *haptic;
    93 
    94    if ((device_index < 0) || (device_index >= SDL_numhaptics)) {
    95       SDL_SetError("There are %d haptic devices available", SDL_numhaptics);
    96       return NULL;
    97    }
    98 
    99    /* If the haptic is already open, return it */
   100    for (i=0; SDL_haptics[i]; i++) {             
   101       if (device_index == SDL_haptics[i]->index) {
   102          haptic = SDL_haptics[i];
   103          ++haptic->ref_count;
   104          return haptic;
   105       }
   106    }
   107 
   108    /* Create the haptic device */
   109    haptic = (SDL_Haptic *) SDL_malloc((sizeof *haptic));
   110    if (haptic == NULL) {
   111       SDL_OutOfMemory();
   112       return NULL;
   113    }
   114 
   115    /* Initialize the haptic device */
   116    SDL_memset(haptic, 0, (sizeof *haptic));
   117    haptic->index = device_index;
   118    if (SDL_SYS_HapticOpen(haptic) < 0) {
   119       SDL_free(haptic);
   120       return NULL;
   121    }
   122 
   123    /* Add haptic to list */
   124    ++haptic->ref_count;
   125    for (i = 0; SDL_haptics[i]; ++i)
   126       /* Skip to next haptic */ ;
   127    SDL_haptics[i] = haptic;
   128 
   129    return haptic;
   130 }
   131 
   132 
   133 /*
   134  * Checks to see if the haptic device is valid
   135  */
   136 static int
   137 ValidHaptic(SDL_Haptic ** haptic)
   138 {
   139    int valid;
   140 
   141    if (*haptic == NULL) {
   142       SDL_SetError("Haptic device hasn't been opened yet");
   143       valid = 0;
   144    } else {
   145       valid = 1;
   146    }
   147    return valid;
   148 }
   149 
   150 
   151 /*
   152  * Closes a SDL_Haptic device.
   153  */
   154 void
   155 SDL_HapticClose(SDL_Haptic * haptic)
   156 {
   157    int i;
   158 
   159    /* Must be valid */
   160    if (!ValidHaptic(&haptic)) {
   161       return;
   162    }
   163 
   164    /* Check if it's still in use */
   165    if (--haptic->ref_count < 0) {
   166       return;
   167    }
   168 
   169    /* Close it */
   170    SDL_SYS_HapticClose(haptic);
   171 
   172    /* Remove from the list */
   173    for (i = 0; SDL_haptics[i]; ++i) {
   174       if (haptic == SDL_haptics[i]) {
   175          SDL_memcpy(&SDL_haptics[i], &SDL_haptics[i + 1],
   176                (SDL_numhaptics - i) * sizeof(haptic));
   177          break;
   178       }
   179    }
   180 
   181    /* Free */
   182    SDL_free(haptic);
   183 }
   184 
   185 /*
   186  * Cleans up after the subsystem.
   187  */
   188 void
   189 SDL_HapticQuit(void)
   190 {
   191    SDL_numhaptics = 0;
   192 
   193    SDL_SYS_HapticQuit();
   194    if (SDL_haptics != NULL) {
   195       SDL_free(SDL_haptics);
   196       SDL_haptics = NULL;
   197    }
   198 }
   199 
   200 
   201 /*
   202  * Creates a new haptic effect.
   203  */
   204 int
   205 SDL_HapticNewEffect(SDL_Haptic * haptic, SDL_HapticEffect * effect)
   206 {
   207    int i;
   208 
   209    /* Check for device validity. */
   210    if (!ValidHaptic(&haptic)) {
   211       return -1;
   212    }
   213 
   214    /* See if there's a free slot */
   215    for (i=0; i<haptic->neffects; i++) {
   216       if (haptic->effects[i].hweffect == NULL) {
   217 
   218          /* Now let the backend create the real effect */
   219          if (SDL_SYS_HapticNewEffect(haptic,&haptic->effects[i]) != 0) {
   220             return -1; /* Backend failed to create effect */
   221          }
   222          return i;
   223       }
   224    }
   225 
   226    SDL_SetError("Haptic device has no free space left.");
   227    return -1;
   228 }
   229 
   230 /*
   231  * Runs the haptic effect on the device.
   232  */
   233 int
   234 SDL_HapticRunEffect(SDL_Haptic * haptic, int effect)
   235 {
   236    if (!ValidHaptic(&haptic)) {
   237       return -1;
   238    }
   239 }
   240 
   241 /*
   242  * Gets rid of a haptic effect.
   243  */
   244 void
   245 SDL_HapticDestroyEffect(SDL_Haptic * haptic, int effect)
   246 {
   247    if (!ValidHaptic(&haptic)) {
   248       return;
   249    }
   250 }
   251 
   252