[cola]

Yes, I agree. I thought I still needed to have touchAlyssumProtocol because it sets ev.time = TimeVal:now(), but now that I look at it again I think it's redundant.

I think this patch is basically how I want it to be, but I haven't run it! So there's probably some dumb syntax error in there or some other problem.

Spoiler:

diff -U 3 -r koreader/frontend/device/input.lua koreader2/frontend/device/input.lua
--- koreader/frontend/device/input.lua	2018-02-12 02:36:04.000000000 -0500
+++ koreader2/frontend/device/input.lua	2018-03-01 15:21:21.631488838 -0500
@@ -411,10 +411,32 @@
         if ev.code == SYN_REPORT then
             for _, MTSlot in pairs(self.MTSlots) do
                 self:setMtSlot(MTSlot.slot, "timev", TimeVal:new(ev.time))
+                if self.snow_protocol then
+                    -- if a slot appears in the current touch event, clear "unused"
+                    self:setMtSlot(MTSlot.slot, "unused", nil) 
+                end
+            end
+            if self.snow_protocol then
+                -- reset every slot that doesn't appear in the current touch event
+                -- (because on the H2O2, this is the only way we detect finger-up)
+                self.MTSlots = {}
+                for _, slot in pairs(self.ev_slots) do
+                    table.insert(self.MTSlots, slot)
+                    if slot.unused then
+                        slot.id = -1
+                        slot.timev = TimeVal:new(ev.time)
+                    end
+                end
             end
             -- feed ev in all slots to state machine
             local touch_ges = self.gesture_detector:feedEvent(self.MTSlots)
             self.MTSlots = {}
+            if self.snow_protocol then
+                -- go through all the ev_slots and set them to unused
+                for _, slot in pairs(self.ev_slots) do
+                    slot.unused = true
+                end
+            end
             if touch_ges then
                 self:gestureAdjustHook(touch_ges)
                 return Event:new("Gesture",
diff -U 3 -r koreader/frontend/device/kobo/device.lua koreader2/frontend/device/kobo/device.lua
--- koreader/frontend/device/kobo/device.lua	2018-02-12 02:36:04.000000000 -0500
+++ koreader2/frontend/device/kobo/device.lua	2018-03-01 15:21:34.948594206 -0500
@@ -104,7 +104,8 @@
 local KoboSnow = Kobo:new{
     model = "Kobo_snow",
     hasFrontlight = yes,
-    touch_alyssum_protocol = true,
+    touch_snow_protocol = true,
+    touch_mirrored_x = false,
     touch_probe_ev_epoch_time = true,
     display_dpi = 265,
     -- the bezel covers the top 11 pixels:
@@ -296,6 +297,10 @@
         self.input:registerEventAdjustHook(adjustTouchAlyssum)
     end
 
+    if self.touch_snow_protocol then
+        self.input.snow_protocol = true
+    end
+
     if self.touch_probe_ev_epoch_time then
         self.input:registerEventAdjustHook(function(_, ev)
             probeEvEpochTime(_, ev)