Implemented polar coordinates in linux.

SDL_ConditionEffect now takes into account both axes.
libsdl-org · Jul 6, 2008 · 8d55260 · 8d55260
1 parent 63bd05c
commit 8d55260
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Showing 2 changed files with 58 additions and 18 deletions.
diff --git a/include/SDL_haptic.h b/include/SDL_haptic.h
@@ -450,13 +450,17 @@ typedef struct SDL_HapticPeriodic {
  * \brief A structure containing a template for a Condition effect.
  *
  * Direction is handled by condition internals instead of a direction member.
+ *  Each of right_sat, lefT-sat, right_coeff, left_coeff, deadband and center
+ *  have two parameters, first is for x value, second is for y value following
+ *  the scheme set by SDL_HapticDirection.
  *
  * The struct handles the following effects:
  *   - SDL_HAPTIC_SPRING: Effect based on axes position.
  *   - SDL_HAPTIC_DAMPER: Effect based on axes velocity.
  *   - SDL_HAPTIC_INERTIA: Effect based on axes acceleration.
  *   - SDL_HAPTIC_FRICTION: Effect based on axes movement.
  *
+ * \sa SDL_HapticDirection
  * \sa SDL_HAPTIC_SPRING
  * \sa SDL_HAPTIC_DAMPER
  * \sa SDL_HAPTIC_INERTIA
@@ -476,12 +480,12 @@ typedef struct SDL_HapticCondition {
    Uint16 interval; /**< How soon it can be triggered again after button. */
 
    /* Condition */
-   Uint16 right_sat; /**< Level when joystick is to the right. */
-   Uint16 left_sat; /**< Level when joystick is to the left. */
-   Sint16 right_coeff; /**< How fast to increase the force towards the right. */
-   Sint16 left_coeff; /**< How fast to increase the force towards the left. */
-   Uint16 deadband; /**< Size of the dead zone. */
-   Sint16 center; /**< Position of the dead zone. */
+   Uint16 right_sat[2]; /**< Level when joystick is to the right. */
+   Uint16 left_sat[2]; /**< Level when joystick is to the left. */
+   Sint16 right_coeff[2]; /**< How fast to increase the force towards the right. */
+   Sint16 left_coeff[2]; /**< How fast to increase the force towards the left. */
+   Uint16 deadband[2]; /**< Size of the dead zone. */
+   Sint16 center[2]; /**< Position of the dead zone. */
 } SDL_HapticCondition;
 /**
  * \struct SDL_HapticRamp
@@ -574,7 +578,7 @@ typedef union SDL_HapticEffect {
    Uint16 type; /**< Effect type. */
    SDL_HapticConstant constant; /**< Constant effect. */
    SDL_HapticPeriodic periodic; /**< Periodic effect. */
-   SDL_HapticCondition condition[2]; /**< Condition effect, one for each axis. */
+   SDL_HapticCondition condition; /**< Condition effect. */
    SDL_HapticRamp ramp; /**< Ramp effect. */
 } SDL_HapticEffect;
 

diff --git a/src/haptic/linux/SDL_syshaptic.c b/src/haptic/linux/SDL_syshaptic.c
@@ -111,6 +111,9 @@ EV_IsHaptic(int fd)
    return ret;
 }
 
+/*
+ * Initializes the haptic subsystem by finding available devices.
+ */
 int
 SDL_SYS_HapticInit(void)
 {
@@ -328,6 +331,31 @@ SDL_SYS_HapticQuit(void)
    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;
+
+   switch (dir->type) {
+      case SDL_HAPTIC_POLAR:
+         tmp = ((dir->dir[0] % 36000) * 0xFFFF) / 36000;
+         return (Uint16) tmp;
+         break;
+      case SDL_HAPTIC_CARTESIAN:
+         /* TODO implement cartesian for linux since it's not supported
+          * by driver */
+         break;
+
+      default:
+         return -1;
+   }
+
+   return 0;
+}
+
 #define  CLAMP(x)    (((x) > 32767) ? 32767 : x)
 /*
  * Initializes the linux effect struct from a haptic_effect.
@@ -351,7 +379,7 @@ SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )
 
          /* Header */
          dest->type = FF_CONSTANT;
-         dest->direction = CLAMP(constant->direction);
+         dest->direction = SDL_SYS_ToDirection(&constant->direction);
 
          /* Replay */
          dest->replay.length = CLAMP(constant->length);
@@ -381,7 +409,7 @@ SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )
 
          /* Header */
          dest->type = FF_PERIODIC;
-         dest->direction = CLAMP(periodic->direction);
+         dest->direction = SDL_SYS_ToDirection(&periodic->direction);
 
          /* Replay */
          dest->replay.length = CLAMP(periodic->length);
@@ -430,7 +458,7 @@ SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )
             dest->type = FF_INERTIA;
          else if (dest->type == SDL_HAPTIC_FRICTION)
             dest->type = FF_FRICTION;
-         dest->direction = CLAMP(condition->direction);
+         dest->direction = 0; /* Handled by the condition-specifics. */
 
          /* Replay */
          dest->replay.length = CLAMP(condition->length);
@@ -440,13 +468,21 @@ SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )
          dest->trigger.button = CLAMP(condition->button);
          dest->trigger.interval = CLAMP(condition->interval);
 
-         /* Condition - TODO handle axes */
-         dest->u.condition[0].right_saturation = CLAMP(condition->right_sat);
-         dest->u.condition[0].left_saturation = CLAMP(condition->left_sat);
-         dest->u.condition[0].right_coeff = condition->right_coeff;
-         dest->u.condition[0].left_coeff = condition->left_coeff;
-         dest->u.condition[0].deadband = CLAMP(condition->deadband);
-         dest->u.condition[0].center = condition->center;
+         /* 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;
 
@@ -455,7 +491,7 @@ SDL_SYS_ToFFEffect( struct ff_effect * dest, SDL_HapticEffect * src )
 
          /* Header */
          dest->type = FF_RAMP;
-         dest->direction = CLAMP(ramp->direction);
+         dest->direction = SDL_SYS_ToDirection(&ramp->direction);
 
          /* Replay */
          dest->replay.length = CLAMP(ramp->length);