Initial limit look at distance code

Author: FelixWolf

indra/newview/app_settings/settings.xml

@@ -16267,5 +16267,27 @@
       <key>Value</key>
       <integer>1</integer>
     </map>
+    <key>LimitLookAtHints</key>
+    <map>
+      <key>Comment</key>
+      <string>Whether or not to clamp the look at targets around the avatar head before sending</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>1</integer>
+    </map>
+    <key>LimitLookAtHintsDistance</key>
+    <map>
+      <key>Comment</key>
+      <string>Distance to limit look at target to</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>F32</string>
+      <key>Value</key>
+      <integer>4</integer>
+    </map>
 </map>
 </llsd>

indra/newview/llhudeffectlookat.cpp

@@ -37,6 +37,7 @@
 #include "lldrawable.h"
 #include "llviewerobjectlist.h"
 #include "llviewercontrol.h"
+#include "llvoavatarself.h"
 #include "llrendersphere.h"
 #include "llselectmgr.h"
 #include "llglheaders.h"
@@ -390,7 +391,7 @@ void LLHUDEffectLookAt::setTargetPosGlobal(const LLVector3d &target_pos_global)
 // setLookAt()
 // called by agent logic to set look at behavior locally, and propagate to sim
 //-----------------------------------------------------------------------------
-bool LLHUDEffectLookAt::setLookAt(ELookAtType target_type, LLViewerObject *object, LLVector3 position)
+bool LLHUDEffectLookAt::setLookAt(ELookAtType target_type, LLViewerObject* object, LLVector3 position)
 {
     static LLCachedControl<bool> enable_lookat_hints(gSavedSettings, "EnableLookAtHints", true);
     if (!enable_lookat_hints)
@@ -415,6 +416,29 @@ bool LLHUDEffectLookAt::setLookAt(ELookAtType target_type, LLViewerObject *objec
         return false;
     }
 
+    static LLCachedControl<bool> limit_lookat_hints(gSavedSettings, "LimitLookAtHints", true);
+    // Don't affect the look at if object is gAgentAvatarp (cursor head follow)
+    if (limit_lookat_hints && object != gAgentAvatarp)
+    {
+        // If it is a object
+        if (object)
+        {
+            position += object->getRenderPosition();
+            object = NULL;
+        }
+
+        LLVector3 agentHeadPosition = gAgentAvatarp->mHeadp->getWorldPosition();
+        float dist = (float)dist_vec(agentHeadPosition, position);
+
+        static LLCachedControl<F32> limit_lookat_hints_distance(gSavedSettings, "LimitLookAtHintsDistance", 2.0f);
+        if (dist > limit_lookat_hints_distance)
+        {
+            LLVector3 headOffset = position - agentHeadPosition;
+            headOffset *= limit_lookat_hints_distance / dist;
+            position.setVec(agentHeadPosition + headOffset);
+        }
+    }
+
     F32 current_time  = mTimer.getElapsedTimeF32();
 
     // type of lookat behavior or target object has changed