more terse packing for GameControlData message

4 files changed, 48 insertions, 28 deletions

diff --git a/indra/newview/llagent.cpp b/indra/newview/llagent.cpp
index a84f8adab9..e948c8bb64 100644
--- a/indra/newview/llagent.cpp
+++ b/indra/newview/llagent.cpp
@@ -5305,7 +5305,6 @@ void LLAgent::applyExternalActions(const LLGameControl::AgentActions& actions)
 void LLAgent::toggleFlycam()
 {
     mUsingFlycam = !mUsingFlycam;
-    LL_INFOS("adebug") << "using_flycam=" << mUsingFlycam << LL_ENDL; // adebug
     if (mUsingFlycam)
     {
         // copy main camera transform to flycam
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index b3331d4b06..88925e6aa8 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -1378,27 +1378,45 @@ void sendGameControlData()
     msg->addU8Fast(_PREHASH_ActionMode, state.mActionMode);
 
     // Non-modal canonical axes/buttons: pack every available value every message,
-    // whether or not it changed since the last one (no per-field diffing).
+    // whether or not it changed since the last one (no per-field diffing). Trailing
+    // zero axes are truncated and the Buttons block is skipped entirely when zero --
+    // the server assumes anything not packed is zero -- to save bytes.
     size_t num_axes = state.mAxes.size();
-    for (U8 i = 0; i < num_axes; ++i)
+    while (num_axes > 0 && state.mAxes[num_axes - 1] == 0)
+    {
+        --num_axes;
+    }
+    for (size_t i = 0; i < num_axes; ++i)
     {
         msg->nextBlockFast(_PREHASH_Axes);
         msg->addS16Fast(_PREHASH_Value, state.mAxes[i]);
     }
-    msg->nextBlockFast(_PREHASH_Buttons);
-    msg->addU32Fast(_PREHASH_Flags, state.mButtons);
+    if (state.mButtons != 0)
+    {
+        msg->nextBlockFast(_PREHASH_Buttons);
+        msg->addU32Fast(_PREHASH_Flags, state.mButtons);
+    }
 
-    // Modal semantic axes/buttons: same always-pack-everything policy, but the
-    // number of axes packed depends on ActionMode -- see message_template.msg's
-    // GameControlData doc and LLGameControl::numSemanticAxesForMode().
-    U8 num_mode_axes = LLGameControl::numSemanticAxesForMode((LLGameControl::AgentControlMode)state.mActionMode);
-    for (U8 i = 0; i < num_mode_axes; ++i)
+    // Modal semantic axes/buttons: same truncation policy, except the number of
+    // axes considered depends on ActionMode -- see message_template.msg's
+    // GameControlData doc and LLGameControl::numSemanticAxesForMode() -- since the
+    // server computes its own expected axis count from the mode and zeros anything
+    // not packed.
+    size_t num_mode_axes = LLGameControl::numSemanticAxesForMode((LLGameControl::AgentControlMode)state.mActionMode);
+    while (num_mode_axes > 0 && state.mSemanticAxes[num_mode_axes - 1] == 0)
+    {
+        --num_mode_axes;
+    }
+    for (size_t i = 0; i < num_mode_axes; ++i)
     {
         msg->nextBlockFast(_PREHASH_ModeAxes);
         msg->addS16Fast(_PREHASH_Value, state.mSemanticAxes[i]);
     }
-    msg->nextBlockFast(_PREHASH_ModeButtons);
-    msg->addU32Fast(_PREHASH_Flags, state.mSemanticButtons);
+    if (state.mSemanticButtons != 0)
+    {
+        msg->nextBlockFast(_PREHASH_ModeButtons);
+        msg->addU32Fast(_PREHASH_Flags, state.mSemanticButtons);
+    }
 
     LLGameControl::updateResendPeriod();
     gAgent.sendMessage();
diff --git a/scripts/messages/message_template.msg b/scripts/messages/message_template.msg
index 59077aa43d..e4f2c0844d 100644
--- a/scripts/messages/message_template.msg
+++ b/scripts/messages/message_template.msg
@@ -9298,20 +9298,20 @@ version 2.0
     }
 }
 
-// GameControlData
 // viewer -> simulator
 // GameControlData - data from game controller
+// Carries canonical gamepad state plus mode-dependent semantic interpretation.
+// Replaces the deprecated GameControlInput (High 32).
 //
 // The Packet field of the AgentData is an increasing sequence number (with overflow
 // after 255) for each GameControlData message, used to ignore late arrivals for
-// out-of-order GameControlData messages.
+// out-of-order messages.
 //
 // The ActionMode field of the AgentData block represents the viewer's game-control
 // mode and is used to assign meaning to the semantic data (see below).
 //
-// Canonical Axes has up to 6 axes: the server will ignore any axes beyond 6 and if
-// fewer than 6 are packed then the server will assume the unpacked axes haven't changed
-// since last message.
+// Canonical Axes has up to 6 Values: the server will ignore any Values beyond 6 and if
+// fewer than 6 are packed then it will assume unpacked Values are zero.
 //   0 AXIS_LEFTX
 //   1 AXIS_LEFTY
 //   2 AXIS_RIGHTX
@@ -9345,22 +9345,22 @@ version 2.0
 //   ...
 //  31 BUTTON_31
 //
-// Semantic data is mostly the same as canonical, but reordered (and combined in the case of the triggers)
-// according to their meaning. The meaning of the semantic axis data depends on the mode.  The modes are:
+// Modal data is mostly the same as canonical, but reordered (and combined in the case of the triggers)
+// according to their semantic meanings, which depend on the mode.  The possible modes are:
 //   0 CONTROL_MODE_AVATAR
 //   1 CONTROL_MODE_MOUSELOOK
 //   2 CONTROL_MODE_FLYCAM
 //   3 CONTROL_MODE_CAPTIVE (sitting)
 //   4 CONTROL_MODE_MOUSE (mouse cursor)
 //
-// For AVATAR, MOUSELOOK, and CAPTIVE modes the axes are:
+// For AVATAR, MOUSELOOK, and CAPTIVE modes the semantics are:
 //   0 AXIS_STRAFE
 //   1 AXIS_ADVANCE
 //   2 AXIS_TURN
 //   3 AXIS_LOOK
 //   4 AXIS_RISE
 //
-// For FLYCAM the axes are:
+// For FLYCAM the semantics are:
 //   0 FLYCAM_AXIS_TRUCK
 //   1 FLYCAM_AXIS_DOLLY
 //   2 FLYCAM_AXIS_PAN
@@ -9375,10 +9375,9 @@ version 2.0
 //   2 AXIS_TURN
 //   3 AXIS_LOOK
 //
-// Similarly for semantic buttons the meaning of the bits depend on the mode:
-// TODO: document the semantic button bits for the various modes.
-// Carries canonical gamepad state plus mode-dependent semantic interpretation.
-// Replaces the deprecated GameControlInput (High 32).
+// Similarly for semantic ModeButtons the meaning of the Flags depend on the mode:
+// TODO: document the ModeButton Flags for the various modes.
+//
 {
     GameControlData High 33 NotTrusted Zerocoded
     {
@@ -9390,20 +9389,24 @@ version 2.0
     }
     // non-modal canonical data
     {
+        // server will zero unpacked Values
         Axes Variable
         { Value S16 }
     }
     {
-        Buttons Single
+        // server will zero unpacked Flags
+        Buttons Variable
         { Flags U32 }
     }
     // modal semantic data
     {
+        // server will zero unpacked Values
         ModeAxes Variable
         { Value S16 }
     }
     {
-        ModeButtons Single
+        // server will zero unpacked Flags
+        ModeButtons Variable
         { Flags U32 }
     }
 }
diff --git a/scripts/messages/message_template.msg.sha1 b/scripts/messages/message_template.msg.sha1
index de81fcb401..4d5fb79fbf 100644
--- a/scripts/messages/message_template.msg.sha1
+++ b/scripts/messages/message_template.msg.sha1
@@ -1 +1 @@
-147b08045d51245c55b1297000c8bd1c8e719e57
\ No newline at end of file
+b34ed9a5337e4429e4d2fd91512f48ca07a3de6e
\ No newline at end of file