[PATCH evdev 3/3] Dummy process MT events (protocol A). (rev2)

[Benjamin Tissoires]

In case the driver receives a mt event, it stores it at the first
available place, i.e. it does not overrides older mt values.

At the end, in the EV_SYNC event, it only sends the values it has
filled.

Signed-off-by: Benjamin Tissoires <tissoire at cena.fr>
---
 src/evdev.c |   36 +++++++++++++++++++++++++++++++++---
 src/evdev.h |    1 +
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index 10fe81b..39a5047 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -412,6 +412,8 @@ EvdevProcessValuators(InputInfoPtr pInfo, int v[MAX_VALUATORS], int *num_v,
      */
     else if (pEvdev->abs && pEvdev->tool) {
         memcpy(v, pEvdev->vals, sizeof(int) * pEvdev->num_vals);
+        if (pEvdev->mt_current_touchpoint > pEvdev->mt_max_touchpoints)
+            pEvdev->mt_current_touchpoint = pEvdev->mt_max_touchpoints;
 
         if (pEvdev->swap_axes) {
             int tmp = v[0];
@@ -438,7 +440,8 @@ EvdevProcessValuators(InputInfoPtr pInfo, int v[MAX_VALUATORS], int *num_v,
             v[1] = (pEvdev->absinfo[ABS_Y].maximum - v[1] +
                     pEvdev->absinfo[ABS_Y].minimum);
 
-        *num_v = pEvdev->num_vals;
+        *num_v = pEvdev->num_vals - (pEvdev->mt_max_touchpoints -
+              pEvdev->mt_current_touchpoint) * pEvdev->mt_num_valuators;
         *first_v = 0;
     }
 }
@@ -540,7 +543,15 @@ EvdevProcessAbsoluteMotionEvent(InputInfoPtr pInfo, struct input_event *ev)
     if (EvdevWheelEmuFilterMotion(pInfo, ev))
         return;
 
-    pEvdev->vals[pEvdev->axis_map[ev->code]] = value;
+    if (ev->code < ABS_MT_TOUCH_MAJOR)
+        pEvdev->vals[pEvdev->axis_map[ev->code]] = value;
+    else if (pEvdev->mt_current_touchpoint < pEvdev->mt_max_touchpoints) {
+        /* MT value -> store it at the first available place */
+        pEvdev->vals[pEvdev->axis_map[ev->code] +
+            pEvdev->mt_current_touchpoint * pEvdev->mt_num_valuators] = value;
+    } else
+        return; /* mt-event, but not enough place to store it */
+
     if (ev->code == ABS_X)
         pEvdev->abs |= ABS_X_VALUE;
     else if (ev->code == ABS_Y)
@@ -682,6 +693,22 @@ EvdevProcessSyncEvent(InputInfoPtr pInfo, struct input_event *ev)
     pEvdev->num_queue = 0;
     pEvdev->abs = 0;
     pEvdev->rel = 0;
+    pEvdev->mt_current_touchpoint = 0;
+}
+
+/**
+ * Process the event SYN_MT_REPORT.
+ *
+ * This event is required only in the mt-protocol A (the oldest one). This
+ * protocol now handles devices that does not make tracking, so the processing
+ * consists in incrementing mt_current_touchpoint to be able to place the next
+ * mt-event after this one in the list of valuators.
+ */
+static void
+EvdevProcessMTSyncReport(InputInfoPtr pInfo, struct input_event *ev)
+{
+    EvdevPtr pEvdev = pInfo->private;
+    pEvdev->mt_current_touchpoint++;
 }
 
 /**
@@ -702,7 +729,10 @@ EvdevProcessEvent(InputInfoPtr pInfo, struct input_event *ev)
             EvdevProcessKeyEvent(pInfo, ev);
             break;
         case EV_SYN:
-            EvdevProcessSyncEvent(pInfo, ev);
+            if (ev->code == SYN_MT_REPORT)
+                EvdevProcessMTSyncReport(pInfo, ev);
+            else
+                EvdevProcessSyncEvent(pInfo, ev);
             break;
     }
 }
diff --git a/src/evdev.h b/src/evdev.h
index 852f06c..49733a7 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -197,6 +197,7 @@ typedef struct {
     unsigned int mt_num_valuators;
     unsigned int mt_max_touchpoints; /* the number of simultaneous touchpoints
                                       * the device can support */
+    unsigned int mt_current_touchpoint;
 } EvdevRec, *EvdevPtr;
 
 /* Event posting functions */
-- 
1.7.0.1