Core/Movement: Fix random position finding near edges, avoid big z-coordinate differences

1 files changed, 36 insertions, 2 deletions

diff --git a/src/server/game/Entities/Object/Object.cpp b/src/server/game/Entities/Object/Object.cpp
index c1ecc3b74e7..3528a7f3053 100755
--- a/src/server/game/Entities/Object/Object.cpp
+++ b/src/server/game/Entities/Object/Object.cpp
@@ -2659,8 +2659,42 @@ void WorldObject::GetNearPoint(WorldObject const* /*searcher*/, float &x, float
 void WorldObject::MovePosition(Position &pos, float dist, float angle)
 {
     angle += m_orientation;
-    pos.m_positionX += dist * cos(angle);
-    pos.m_positionY += dist * sin(angle);
+    float destx, desty, destz, ground, floor;
+    destx = pos.m_positionX + dist * cos(angle);
+    desty = pos.m_positionY + dist * sin(angle);
+
+    // Prevent invalid coordinates here, position is unchanged
+    if (!Trinity::IsValidMapCoord(destx, desty))
+    {
+        sLog->outCrash("WorldObject::MovePosition invalid coordinates X: %f and Y: %f were passed!", destx, desty);
+        return;
+    }
+
+    ground = GetMap()->GetHeight(GetPhaseMask(), destx, desty, MAX_HEIGHT, true);
+    floor = GetMap()->GetHeight(GetPhaseMask(), destx, desty, pos.m_positionZ, true);
+    destz = fabs(ground - pos.m_positionZ) <= fabs(floor - pos.m_positionZ) ? ground : floor;
+
+    float step = dist/10.0f;
+
+    for (uint8 j = 0; j < 10; ++j)
+    {
+        // do not allow too big z changes
+        if (fabs(pos.m_positionZ - destz) > 6)
+        {
+            destx -= step * cos(angle);
+            desty -= step * sin(angle);
+            ground = GetMap()->GetHeight(GetPhaseMask(), destx, desty, MAX_HEIGHT, true);
+            floor = GetMap()->GetHeight(GetPhaseMask(), destx, desty, pos.m_positionZ, true);
+            destz = fabs(ground - pos.m_positionZ) <= fabs(floor - pos.m_positionZ) ? ground : floor;
+        }
+        // we have correct destz now
+        else
+        {
+            pos.Relocate(destx, desty, destz);
+            break;
+        }
+    }
+
     Trinity::NormalizeMapCoord(pos.m_positionX);
     Trinity::NormalizeMapCoord(pos.m_positionY);
     UpdateGroundPositionZ(pos.m_positionX, pos.m_positionY, pos.m_positionZ);