Merge lp:~chasedouglas/geis/fix-deltas into lp:geis

[Chase Douglas]

Fix delta calculation when synchronous events are not enabled.

[Stephen M. Webb (bregma)]

Should the radius and angle really be reset to zero when the number of touches change? That doesn't make a lot of sense to me from a functional point of view.

[Chase Douglas (chasedouglas)]

I merely copied and pasted the radius and angle bits. After thinking some more, the angle should be reset to 0 (it's inherently a relative value), and the radius should be reset to 1 as it represents the ratio of the current radius to the original radius.

I'll fix this up.

[lp:~chasedouglas/geis/fix-deltas]

256. By Chase Douglas on 2012-04-20

Calculate radius deltas as a ratio from previous geis event

The radius values are scale factors from the geis begin event, so the
deltas should be scale factors from the previous geis event too.

257. By Chase Douglas on 2012-04-20

Merged delta-test into fix-deltas.

[Chase Douglas (chasedouglas)]

I have fixed the radius deltas now. Please review.

review: Needs Resubmitting

[Stephen M. Webb (bregma)]

OK.

review: Approve

=== modified file 'libutouch-geis/backend/grail/geis_grail_backend.c'
--- libutouch-geis/backend/grail/geis_grail_backend.c	2012-04-18 16:39:21 +0000
+++ libutouch-geis/backend/grail/geis_grail_backend.c	2012-04-20 15:45:25 +0000
@@ -65,7 +65,10 @@
   unsigned int slice_id;
   uint64_t     timestamp;
   GeisFloat    angle;
+  GeisFloat    position_x;
+  GeisFloat    position_y;
   GeisFloat    radius;
+  unsigned int num_touches;
 };
 
 
@@ -195,7 +198,6 @@
                                 GeisFrame               frame)
 {
   UGGestureTypeMask ugmask = grail_slice_get_recognized(slice);
-  const UGTransform *T = grail_slice_get_transform(slice);
   const UGTransform *C = grail_slice_get_cumulative_transform(slice);
 
   geis_frame_add_attr(frame, geis_attr_new(GEIS_GESTURE_ATTRIBUTE_GESTURE_NAME,
@@ -217,14 +219,18 @@
                                              GEIS_ATTR_TYPE_FLOAT,
                                              &position_y));
 
-    GeisFloat delta_x = (*T)[0][2];
+    GeisFloat delta_x = position_x - slice_state->position_x;
     geis_frame_add_attr(frame, geis_attr_new(GEIS_GESTURE_ATTRIBUTE_DELTA_X,
                                              GEIS_ATTR_TYPE_FLOAT,
                                              &delta_x));
-    GeisFloat delta_y = (*T)[1][2];
+    slice_state->position_x = position_x;
+
+    GeisFloat delta_y = position_y - slice_state->position_y;
     geis_frame_add_attr(frame, geis_attr_new(GEIS_GESTURE_ATTRIBUTE_DELTA_Y,
                                              GEIS_ATTR_TYPE_FLOAT,
                                              &delta_y));
+    slice_state->position_y = position_y;
+
     if (delta_t > 0.0f)
     {
       GeisFloat x_velocity = delta_x / delta_t;
@@ -249,7 +255,7 @@
                                              GEIS_ATTR_TYPE_FLOAT,
                                              &r));
 
-    GeisFloat dr = r - slice_state->radius;
+    GeisFloat dr = r / slice_state->radius;
     geis_frame_add_attr(frame, geis_attr_new(GEIS_GESTURE_ATTRIBUTE_RADIUS_DELTA,
                                              GEIS_ATTR_TYPE_FLOAT,
                                              &dr));
@@ -345,16 +351,46 @@
 _grail_be_slice_state_new(GeisGrailBackend gbe,
                           UGSlice          slice)
 {
+  const UGTransform *C = grail_slice_get_cumulative_transform(slice);
   struct _GeisSliceState new_slice_state = {
     .slice_id = grail_slice_get_id(slice),
     .timestamp = 0, 
     .angle = 0.0f,
-    .radius = 0.0f
+    .position_x = grail_slice_get_original_center_x(slice) + (*C)[0][2],
+    .position_y = grail_slice_get_original_center_y(slice) + (*C)[1][2],
+    .radius = 1.0f,
+    .num_touches = grail_slice_get_num_touches(slice)
   };
   geis_bag_append(gbe->slice_states, &new_slice_state);
   return _grail_be_slice_state_from_ugslice(gbe, slice);
 }
 
+/**
+ * Update a slice state for a grail slice.
+ *
+ * @param[in] slice_state the geis slice state
+ * @param[in] slice       a grail slice
+ *
+ * This function resets the slice state if the number of touches has changed.
+ */
+static void
+_grail_be_slice_state_update(struct _GeisSliceState *slice_state, UGSlice slice)
+{
+  
+  if (slice_state->num_touches != grail_slice_get_num_touches(slice))
+  {
+    const UGTransform *C = grail_slice_get_cumulative_transform(slice);
+
+    slice_state->angle = 0.0f;
+    slice_state->position_x = grail_slice_get_original_center_x(slice) +
+                              (*C)[0][2];
+    slice_state->position_x = grail_slice_get_original_center_x(slice) +
+                              (*C)[1][2];
+    slice_state->radius = 1.0f;
+    slice_state->num_touches = grail_slice_get_num_touches(slice);
+  }
+}
+
 
 /**
  * Creates a geis event from a grail slice.
@@ -493,6 +529,8 @@
         slice_state->timestamp = timestamp;
       }
 
+      _grail_be_slice_state_update(slice_state, slice);
+
       GeisGroupSet  groupset = geis_groupset_new();
       GeisAttr      group_attr = geis_attr_new(GEIS_EVENT_ATTRIBUTE_GROUPSET,
                                                GEIS_ATTR_TYPE_POINTER,