From b50f26e08618e22bd10f7ce4ab006f1e9be1329e Mon Sep 17 00:00:00 2001
From: Edgar Simo <bobbens@gmail.com>
Date: Tue, 1 Jul 2008 18:35:05 +0000
Subject: [PATCH] Added SDL_HapticUpdateEffect().

---
 include/SDL_haptic.h             | 10 ++++++++
 src/haptic/SDL_haptic.c          | 19 ++++++++++++++++
 src/haptic/SDL_syshaptic.h       |  2 ++
 src/haptic/linux/SDL_syshaptic.c | 39 ++++++++++++++++++++++++++++++--
 4 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/include/SDL_haptic.h b/include/SDL_haptic.h
index 8eb642ce7..4aa86fed6 100644
--- a/include/SDL_haptic.h
+++ b/include/SDL_haptic.h
@@ -240,6 +240,16 @@ extern DECLSPEC int SDL_HapticEffectSupported(SDL_Haptic * haptic, SDL_HapticEff
  */
 extern DECLSPEC int SDL_HapticNewEffect(SDL_Haptic * haptic, SDL_HapticEffect * effect);
 
+/*
+ * Uploads an effect.  Can be used dynamically, although behaviour when
+ * dynamically changing direction may be strange.  Specifically the effect
+ * may reupload itself and start playing from the start.  You cannot change
+ * the type either when running UpdateEffect.
+ *
+ * Returns the id of the effect on success, -1 on failure.
+ */
+extern DECLSPEC int SDL_HapticUpdateEffect(SDL_Haptic * haptic, int effect, SDL_HapticEffect * data);
+
 /*
  * Runs the haptic effect on it's assosciated haptic device.
  *
diff --git a/src/haptic/SDL_haptic.c b/src/haptic/SDL_haptic.c
index cbe6ad644..84fb5bada 100644
--- a/src/haptic/SDL_haptic.c
+++ b/src/haptic/SDL_haptic.c
@@ -291,6 +291,25 @@ ValidEffect(SDL_Haptic * haptic, int effect)
    return 1;
 }
 
+/*
+ * Updates an effect.
+ */
+int
+SDL_HapticUpdateEffect(SDL_Haptic * haptic, int effect, SDL_HapticEffect * data)
+{
+   if (!ValidHaptic(&haptic) || !ValidEffect(haptic,effect)) {
+      return -1;
+   }
+
+   /* Updates the effect */
+   if (SDL_SYS_HapticUpdateEffect(haptic,&haptic->effects[effect],data) < 0) {
+      return -1;
+   }
+
+   return 0;
+}
+
+
 /*
  * Runs the haptic effect on the device.
  */
diff --git a/src/haptic/SDL_syshaptic.h b/src/haptic/SDL_syshaptic.h
index 71aa66ac3..66dbcd6bc 100644
--- a/src/haptic/SDL_syshaptic.h
+++ b/src/haptic/SDL_syshaptic.h
@@ -54,6 +54,8 @@ 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, SDL_HapticEffect * base);
+extern int SDL_SYS_HapticUpdateEffect(SDL_Haptic * haptic,
+      struct haptic_effect * effect, SDL_HapticEffect * data);
 extern int SDL_SYS_HapticRunEffect(SDL_Haptic * haptic,
       struct haptic_effect * effect);
 extern int SDL_SYS_HapticStopEffect(SDL_Haptic * haptic,
diff --git a/src/haptic/linux/SDL_syshaptic.c b/src/haptic/linux/SDL_syshaptic.c
index 55e5b025b..606eeb94e 100644
--- a/src/haptic/linux/SDL_syshaptic.c
+++ b/src/haptic/linux/SDL_syshaptic.c
@@ -456,17 +456,52 @@ SDL_SYS_HapticNewEffect(SDL_Haptic * haptic, struct haptic_effect * effect,
    /* Prepare the ff_effect */
    linux_effect = &effect->hweffect->effect;
    if (SDL_SYS_ToFFEffect( linux_effect, base ) != 0) {
-      return -1;
+      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("Error uploading effect to the haptic device.");
-      return -1;
+      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("Error updating the haptic effect.");
+      return -1;
+   }
+
+   /* Copy the new effect into memory. */
+   SDL_memcpy( &effect->hweffect->effect, &linux_effect, sizeof(struct ff_effect) );
+
+   return effect->hweffect->effect.id;
 }