change rotation units to angles

Use angle units, such that a complete revolution corresponds
to 2 pi.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

2 files changed, 8 insertions, 8 deletions

diff --git a/include/grail-types.h b/include/grail-types.h
index 9f7160d..83a653c 100644
--- a/include/grail-types.h
+++ b/include/grail-types.h
@@ -64,9 +64,9 @@
 #define GRAIL_PROP_PINCH_X2     5       /* bounding box x2 */
 #define GRAIL_PROP_PINCH_Y2     6       /* bounding box y2 */
 
-#define GRAIL_PROP_ROTATE_DA    0       /* arc delta */
-#define GRAIL_PROP_ROTATE_VA    1       /* arc velocity */
-#define GRAIL_PROP_ROTATE_A     2       /* arc */
+#define GRAIL_PROP_ROTATE_DA    0       /* angle delta */
+#define GRAIL_PROP_ROTATE_VA    1       /* angular velocity */
+#define GRAIL_PROP_ROTATE_A     2       /* angle */
 
 #define GRAIL_PROP_TAP_DT       0       /* tap time (ms) */
 #define GRAIL_PROP_TAP_X        1       /* horizontal position */
diff --git a/src/grail-gestures.c b/src/grail-gestures.c
index 1d49765..be53cc0 100644
--- a/src/grail-gestures.c
+++ b/src/grail-gestures.c
@@ -69,7 +69,7 @@ static float compute_rotation(float x, float y, float r,
                               const struct touch_frame *frame)
 {
         int i, n = frame->nactive;
-        float da = 0, da2 = 0;
+        float da = 0, darc2 = 0;
         if (n < 2)
                 return da;
         for (i = 0; i < n; i++) {
@@ -79,10 +79,10 @@ static float compute_rotation(float x, float y, float r,
                 float dy = t->prop[TP_POS_Y] - y;
                 float mx = t->prop[TP_POS_X] - ot->prop[TP_POS_X];
                 float my = t->prop[TP_POS_Y] - ot->prop[TP_POS_Y];
-                da2 += dx * my - dy * mx;
+                darc2 += dx * my - dy * mx;
         }
-        da2 /= n;
-        da = da2 / r;
+        darc2 /= n;
+        da = darc2 / (r * r);
         return da;
 }
 
@@ -150,7 +150,7 @@ void gru_init_motion(struct grail *ge)
         D[FM_X] = max.x - min.x;
         D[FM_Y] = max.y - min.y;
         D[FM_R] = sqrt(D[FM_X] * D[FM_X] + D[FM_Y] * D[FM_Y]);
-        D[FM_A] = D[FM_R];
+        D[FM_A] = 2 * M_PI;
         for (i = 0; i < DIM_FM; i++) {
                 m->fm[i].fuzz = D[i] / FM_SN[i];
                 m->fm[i].bar = D[i] / FM_BAR[i];