vdi-cloud/terminal/moonlight/patches/0002-vdi-absolute-click-barrier.patch

--- a/src/InputStream.c
+++ b/src/InputStream.c
@@ -86,11 +86,16 @@
     int deltaX, deltaY;
     bool dirty; // Update ready to send (queued packet holder in packetQueue)
 } currentRelativeMouseState;
-static struct {
-    int x, y;
-    int width, height;
-    bool dirty; // Update ready to send (queued packet holder in packetQueue)
-} currentAbsoluteMouseState;
+// Only this packet may absorb newer positions. A button event seals the batch.
+static PPACKET_HOLDER currentQueuedAbsoluteMousePacket;
+
+static void latchAbsoluteMousePacket(PPACKET_HOLDER holder) {
+    PltLockMutex(&batchedInputMutex);
+    if (currentQueuedAbsoluteMousePacket == holder) {
+        currentQueuedAbsoluteMousePacket = NULL;
+    }
+    PltUnlockMutex(&batchedInputMutex);
+}
 
 // Initializes the input stream
 int initializeInputStream(void) {
@@ -120,7 +125,7 @@
 
     memset(currentGamepadSensorState, 0, sizeof(currentGamepadSensorState));
     memset(&currentRelativeMouseState, 0, sizeof(currentRelativeMouseState));
-    memset(&currentAbsoluteMouseState, 0, sizeof(currentAbsoluteMouseState));
+    currentQueuedAbsoluteMousePacket = NULL;
     PltCreateMutex(&batchedInputMutex);
 
     return 0;
@@ -444,24 +449,9 @@
                 now = PltGetMillis();
             }
 
-            PltLockMutex(&batchedInputMutex);
-
-            // Populate the packet with the latest state
-            holder->packet.mouseMoveAbs.x = BE16(currentAbsoluteMouseState.x);
-            holder->packet.mouseMoveAbs.y = BE16(currentAbsoluteMouseState.y);
-
-            // There appears to be a rounding error in GFE's scaling calculation which prevents
-            // the cursor from reaching the far edge of the screen when streaming at smaller
-            // resolutions with a higher desktop resolution (like streaming 720p with a desktop
-            // resolution of 1080p, or streaming 720p/1080p with a desktop resolution of 4K).
-            // Subtracting one from the reference dimensions seems to work around this issue.
-            holder->packet.mouseMoveAbs.width = BE16(currentAbsoluteMouseState.width - 1);
-            holder->packet.mouseMoveAbs.height = BE16(currentAbsoluteMouseState.height - 1);
-
-            // The state change is no longer pending
-            currentAbsoluteMouseState.dirty = false;
-
-            PltUnlockMutex(&batchedInputMutex);
+            // Payload was filled by the producer under the same mutex. Latch
+            // only our packet; a later batch may already be queued after a click.
+            latchAbsoluteMousePacket(holder);
 
             lastMousePacketTime = now;
         }
@@ -780,52 +770,37 @@
     }
 
     PltLockMutex(&batchedInputMutex);
-
-    // Overwrite the previous mouse location with the new one
-    currentAbsoluteMouseState.x = x;
-    currentAbsoluteMouseState.y = y;
-    currentAbsoluteMouseState.width = referenceWidth;
-    currentAbsoluteMouseState.height = referenceHeight;
-
-    // Queue a packet holder if this is the only pending absolute mouse event
-    if (!currentAbsoluteMouseState.dirty) {
-        // Set the dirty flag to claim ownership of inserting the packet holder
-        // and unlock to allow other threads to enqueue or process input.
-        currentAbsoluteMouseState.dirty = true;
-        PltUnlockMutex(&batchedInputMutex);
-
+    holder = currentQueuedAbsoluteMousePacket;
+    bool newPacket = holder == NULL;
+    if (newPacket) {
         holder = allocatePacketHolder(0);
         if (holder == NULL) {
-            currentAbsoluteMouseState.dirty = false;
+            PltUnlockMutex(&batchedInputMutex);
             return -1;
         }
-
         holder->channelId = CTRL_CHANNEL_MOUSE;
-
-        // TODO: Send this as unreliable sequenced when we have a delayed reliable retransmission thread
         holder->enetPacketFlags = ENET_PACKET_FLAG_RELIABLE;
-
         holder->packet.mouseMoveAbs.header.size = BE32(sizeof(NV_ABS_MOUSE_MOVE_PACKET) - sizeof(uint32_t));
         holder->packet.mouseMoveAbs.header.magic = LE32(MOUSE_MOVE_ABS_MAGIC);
         holder->packet.mouseMoveAbs.unused = 0;
-
-        // Remaining fields are set in the input thread based on the latest currentAbsoluteMouseState values
-
+    }
+    holder->packet.mouseMoveAbs.x = BE16(x);
+    holder->packet.mouseMoveAbs.y = BE16(y);
+    // Preserve upstream's far-edge rounding workaround.
+    holder->packet.mouseMoveAbs.width = BE16(referenceWidth - 1);
+    holder->packet.mouseMoveAbs.height = BE16(referenceHeight - 1);
+    err = 0;
+    if (newPacket) {
+        currentQueuedAbsoluteMousePacket = holder;
         err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
         if (err != LBQ_SUCCESS) {
+            currentQueuedAbsoluteMousePacket = NULL;
             LC_ASSERT(err == LBQ_BOUND_EXCEEDED);
             Limelog("Input queue reached maximum size limit\n");
             freePacketHolder(holder);
-
-            // We weren't able to insert the entry, so let the next call try again
-            currentAbsoluteMouseState.dirty = false;
-        }
-    }
-    else {
-        // There's already a packet holder queued to send this event
-        PltUnlockMutex(&batchedInputMutex);
-        err = 0;
-    }
+        }
+    }
+    PltUnlockMutex(&batchedInputMutex);
 
     // This is not thread safe, but it's not a big deal because callers that want to
     // use LiSendRelativeMotionAsMousePositionEvent() must not mix these function
@@ -872,7 +847,11 @@
     holder->packet.mouseButton.header.magic = LE32(holder->packet.mouseButton.header.magic);
     holder->packet.mouseButton.button = (uint8_t)button;
 
+    PltLockMutex(&batchedInputMutex);
+    // Do not let a later position overwrite the move preceding this click.
+    currentQueuedAbsoluteMousePacket = NULL;
     err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
+    PltUnlockMutex(&batchedInputMutex);
     if (err != LBQ_SUCCESS) {
         LC_ASSERT(err == LBQ_BOUND_EXCEEDED);
         Limelog("Input queue reached maximum size limit\n");