From 89732989ff60119f74203e22116655027b503551 Mon Sep 17 00:00:00 2001
From: Edgar Simo <bobbens@gmail.com>
Date: Mon, 30 Jun 2008 21:38:29 +0000
Subject: [PATCH] Added some preliminary support for haptic effect control.

---
 src/haptic/SDL_haptic.c          | 14 ++++++
 src/haptic/SDL_syshaptic.h       |  7 +++
 src/haptic/linux/SDL_syshaptic.c | 81 +++++++++++++++++++++++++++++++-
 3 files changed, 100 insertions(+), 2 deletions(-)

diff --git a/src/haptic/SDL_haptic.c b/src/haptic/SDL_haptic.c
index a987ac65b..57a5c7671 100644
--- a/src/haptic/SDL_haptic.c
+++ b/src/haptic/SDL_haptic.c
@@ -273,6 +273,13 @@ SDL_HapticRunEffect(SDL_Haptic * haptic, int effect)
    if (!ValidHaptic(&haptic)) {
       return -1;
    }
+
+   /* Run the effect */
+   if (SDL_SYS_HapticRunEffect(haptic,&haptic->effects[effect]) < 0) {
+      return -1;
+   }
+
+   return 0;
 }
 
 /*
@@ -284,6 +291,13 @@ SDL_HapticDestroyEffect(SDL_Haptic * haptic, int effect)
    if (!ValidHaptic(&haptic)) {
       return;
    }
+
+   /* Not allocated */
+   if (haptic->effects[effect].hweffect == NULL) {
+      return;
+   }
+
+   SDL_SYS_HapticDestroyEffect(haptic, &haptic->effects[effect]);
 }
 
 
diff --git a/src/haptic/SDL_syshaptic.h b/src/haptic/SDL_syshaptic.h
index 8b9a5ff34..2368f4d0a 100644
--- a/src/haptic/SDL_syshaptic.h
+++ b/src/haptic/SDL_syshaptic.h
@@ -52,4 +52,11 @@ extern const char * SDL_SYS_HapticName(int index);
 extern int SDL_SYS_HapticOpen(SDL_Haptic * haptic);
 extern void SDL_SYS_HapticClose(SDL_Haptic * haptic);
 extern void SDL_SYS_HapticQuit(void);
+extern int SDL_SYS_HapticNewEffect(SDL_Haptic * haptic,
+      struct haptic_effect * effect);
+extern int SDL_SYS_HapticRunEffect(SDL_Haptic * haptic,
+      struct haptic_effect * effect);
+extern void SDL_SYS_HapticDestroyEffect(SDL_Haptic * haptic,
+      struct haptic_effect * effect);
+
 
diff --git a/src/haptic/linux/SDL_syshaptic.c b/src/haptic/linux/SDL_syshaptic.c
index df08ce5fa..8fdad82f6 100644
--- a/src/haptic/linux/SDL_syshaptic.c
+++ b/src/haptic/linux/SDL_syshaptic.c
@@ -64,7 +64,7 @@ struct haptic_hwdata
  */
 struct haptic_hweffect
 {
-   int id;
+   struct ff_effect effect;
 };
 
 
@@ -270,13 +270,90 @@ SDL_SYS_HapticQuit(void)
    SDL_hapticlist[0].fname = NULL;
 }
 
+/*
+ * Initializes the linux effect struct from a haptic_effect.
+ */
+static int
+SDL_SYS_ToFFEffect( struct ff_effect * dest, struct haptic_effect * src )
+{
+   SDL_memset(dest, 0, sizeof(struct ff_effect));
+   switch (src->effect.type) {
+      case SDL_HAPTIC_CONSTANT:
+         dest->type = FF_CONSTANT;
+
+         break;
+
+      default:
+         SDL_SetError("Unknown haptic effect type.");
+         return -1;
+   }
+
+   return 0;
+}
+
 /*
  * Creates a new haptic effect.
  */
 int
 SDL_SYS_HapticNewEffect(SDL_Haptic * haptic, struct haptic_effect * effect)
 {
-   return -1;
+   /* 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 */
+   if (SDL_SYS_ToFFEffect( &effect->hweffect->effect, effect ) != 0) {
+      return -1;
+   }
+   effect->hweffect->effect.id = -1; /* Have the kernel give it an id */
+
+   /* Upload the effect */
+   if (ioctl(haptic->hwdata->fd, EVIOCSFF, &effect->hweffect->effect) < 0) {
+      SDL_SetError("Error uploading effect to the haptic device.");
+      return -1;
+   }
+
+   return 0;
+}
+
+
+/*
+ * Runs an effect.
+ */
+int
+SDL_SYS_HapticRunEffect(SDL_Haptic * haptic, struct haptic_effect * effect)
+{
+   struct input_event run;
+
+   /* Prepare to run the effect */
+   run.type = EV_FF;
+   run.code = effect->hweffect->effect.id;
+   run.value = 1;
+
+   if (write(haptic->hwdata->fd, (const void*) &run, sizeof(run)) < 0) {
+      SDL_SetError("Unable to run the haptic effect.");
+      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("Error removing the effect from the haptic device.");
+   }
+   SDL_free(effect->hweffect);
+   effect->hweffect = NULL;
 }