[PATCH xf86-input-synaptics v2] Prefer multitouch over single-touch axis ranges

[Chase Douglas]

We still use single-touch data in most cases, but sometimes the
multitouch axes have higher resolution. Since we use the same XI
valuators to report ST and MT data, we must pick one axis and scale the
other to match. This change picks the MT axis ranges.

Signed-off-by: Chase Douglas <chase.douglas at canonical.com>
---
Changes since v1:
* Move proto_data members around so they compile when !HAVE_MTDEV
* Initialize scale factors in EventProtoDataAlloc so eventcomm-test passes

 src/eventcomm.c |   45 +++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/src/eventcomm.c b/src/eventcomm.c
index 6ffe265..e97faa8 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -65,6 +65,10 @@ struct eventcomm_proto_data
      * exists for readability of the code.
      */
     BOOL need_grab;
+    int st_to_mt_offset_x;
+    double st_to_mt_scale_x;
+    int st_to_mt_offset_y;
+    double st_to_mt_scale_y;
 #ifdef HAVE_MTDEV
     struct mtdev *mtdev;
     int axis_map[MT_ABS_SIZE];
@@ -76,7 +80,16 @@ struct eventcomm_proto_data
 struct eventcomm_proto_data *
 EventProtoDataAlloc(void)
 {
-    return calloc(1, sizeof(struct eventcomm_proto_data));
+    struct eventcomm_proto_data *proto_data;
+
+    proto_data = calloc(1, sizeof(struct eventcomm_proto_data));
+    if (!proto_data)
+        return NULL;
+
+    proto_data->st_to_mt_scale_x = 1;
+    proto_data->st_to_mt_scale_y = 1;
+
+    return proto_data;
 }
 
 #ifdef HAVE_MTDEV
@@ -363,6 +376,7 @@ static void
 event_query_axis_ranges(InputInfoPtr pInfo)
 {
     SynapticsPrivate *priv = (SynapticsPrivate *)pInfo->private;
+    struct eventcomm_proto_data *proto_data = priv->proto_data;
     unsigned long absbits[NBITS(ABS_MAX)] = {0};
     unsigned long keybits[NBITS(KEY_MAX)] = {0};
     char buf[256] = {0};
@@ -396,6 +410,26 @@ event_query_axis_ranges(InputInfoPtr pInfo)
 		      &priv->minw, &priv->maxw,
 		      NULL, NULL);
 
+    if (priv->has_touch)
+    {
+        int st_minx = priv->minx;
+        int st_maxx = priv->maxx;
+        int st_miny = priv->miny;
+        int st_maxy = priv->maxy;
+
+        event_get_abs(pInfo, pInfo->fd, ABS_MT_POSITION_X, &priv->minx,
+                      &priv->maxx, &priv->synpara.hyst_x, &priv->resx);
+        event_get_abs(pInfo, pInfo->fd, ABS_MT_POSITION_Y, &priv->miny,
+                      &priv->maxy, &priv->synpara.hyst_y, &priv->resy);
+
+        proto_data->st_to_mt_offset_x = priv->minx - st_minx;
+        proto_data->st_to_mt_scale_x =
+            (priv->maxx - priv->minx) / (st_maxx - st_minx);
+        proto_data->st_to_mt_offset_y = priv->miny - st_miny;
+        proto_data->st_to_mt_scale_y =
+            (priv->maxy - priv->miny) / (st_maxy - st_miny);
+    }
+
     SYSCALL(rc = ioctl(pInfo->fd, EVIOCGBIT(EV_KEY, sizeof(keybits)), keybits));
     if (rc >= 0)
     {
@@ -569,6 +603,7 @@ EventReadHwState(InputInfoPtr pInfo,
     struct SynapticsHwState *hw = comm->hwState;
     SynapticsPrivate *priv = (SynapticsPrivate *)pInfo->private;
     SynapticsParameters *para = &priv->synpara;
+    struct eventcomm_proto_data *proto_data = priv->proto_data;
 
     SynapticsResetTouchHwState(hw);
 
@@ -644,10 +679,12 @@ EventReadHwState(InputInfoPtr pInfo,
 	    if (ev.code < ABS_MT_SLOT) {
 		switch (ev.code) {
 		case ABS_X:
-		    hw->x = ev.value;
+		    hw->x = ev.value * proto_data->st_to_mt_scale_x +
+			proto_data->st_to_mt_offset_x;
 		    break;
 		case ABS_Y:
-		    hw->y = ev.value;
+		    hw->y = ev.value * proto_data->st_to_mt_scale_y +
+			proto_data->st_to_mt_offset_y;
 		    break;
 		case ABS_PRESSURE:
 		    hw->z = ev.value;
@@ -816,10 +853,10 @@ EventReadDevDimensions(InputInfoPtr pInfo)
 
     if (event_query_is_touchpad(pInfo->fd, (proto_data) ? proto_data->need_grab : TRUE))
     {
-        event_query_axis_ranges(pInfo);
 #ifdef HAVE_MTDEV
         event_query_touch(pInfo);
 #endif
+        event_query_axis_ranges(pInfo);
     }
     event_query_model(pInfo->fd, &priv->model, &priv->id_vendor, &priv->id_product);
 
-- 
1.7.8.3