split out bounding box computation

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

1 files changed, 24 insertions, 0 deletions

diff --git a/src/grail-gestures.c b/src/grail-gestures.c
index f1e2093..33d848c 100644
--- a/src/grail-gestures.c
+++ b/src/grail-gestures.c
@@ -218,3 +218,27 @@ void gru_end(struct grail *ge, int gid, const struct move_model *m,
                     prop, nprop);
 }
 
+void gru_compute_bbox(struct grail_coord *min, struct grail_coord *max,
+                      const struct touch_frame *frame)
+{
+        float x, y;
+        int i;
+        if (frame->nactive < 1)
+                return;
+        x = frame->active[0]->prop[TP_POS_X];
+        y = frame->active[0]->prop[TP_POS_Y];
+        min->x = max->x = x;
+        min->y = max->y = y;
+        for (i = 1; i < frame->nactive; i++) {
+                x = frame->active[i]->prop[TP_POS_X];
+                y = frame->active[i]->prop[TP_POS_Y];
+                if (x < min->x)
+                        min->x = x;
+                if (y < min->y)
+                        min->y = y;
+                if (x > max->x)
+                        max->x = x;
+                if (y > max->y)
+                        max->y = y;
+        }
+}