Core/Spells: Improve charge path logic, get a point to the target and then reduce it by the necessary distance

3 files changed, 48 insertions, 6 deletions

diff --git a/src/server/game/Movement/PathGenerator.cpp b/src/server/game/Movement/PathGenerator.cpp
index d6912bac7c8..3140fc23296 100644
--- a/src/server/game/Movement/PathGenerator.cpp
+++ b/src/server/game/Movement/PathGenerator.cpp
@@ -882,3 +882,41 @@ float PathGenerator::Dist3DSqr(G3D::Vector3 const& p1, G3D::Vector3 const& p2) c
 {
     return (p1 - p2).squaredLength();
 }
+
+void PathGenerator::ReducePathLenghtByDist(float dist)
+{
+    if (GetPathType() == PATHFIND_BLANK)
+    {
+        TC_LOG_ERROR("maps", "PathGenerator::ReducePathLenghtByDist called before path was built");
+        return;
+    }
+
+    if (_pathPoints.size() < 2) // path building failure
+        return;
+
+    uint32 i = _pathPoints.size();
+    G3D::Vector3 nextVec = _pathPoints[--i];
+    while (i > 0)
+    {
+        G3D::Vector3 currVec = _pathPoints[--i];
+        G3D::Vector3 diffVec = (nextVec - currVec);
+        float len = diffVec.length();
+        if (len > dist)
+        {
+            float step = dist / len;
+            // same as nextVec
+            _pathPoints[i + 1] -= diffVec * step;
+            _pathPoints.resize(i + 2);
+            break;
+        }
+        else if (i == 0) // at second point
+        {
+            _pathPoints[1] = _pathPoints[0];
+            _pathPoints.resize(2);
+            break;
+        }
+
+        dist -= len;
+        nextVec = currVec; // we're going backwards
+    }
+}
diff --git a/src/server/game/Movement/PathGenerator.h b/src/server/game/Movement/PathGenerator.h
index 6e0d72ec8da..a9a13c37251 100644
--- a/src/server/game/Movement/PathGenerator.h
+++ b/src/server/game/Movement/PathGenerator.h
@@ -72,6 +72,8 @@ class PathGenerator
 
         PathType GetPathType() const { return _type; }
 
+        void ReducePathLenghtByDist(float dist); // path must be already built
+
     private:
 
         dtPolyRef _pathPolyRefs[MAX_PATH_LENGTH];   // array of detour polygon references
diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 1407a4975d9..0d7dd8819af 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -5043,22 +5043,24 @@ SpellCastResult Spell::CheckCast(bool strict)
                     if (!target)
                         return SPELL_FAILED_DONT_REPORT;
 
-                    //target->GetContactPoint(m_caster, pos.m_positionX, pos.m_positionY, pos.m_positionZ);
-                    Position pos = target->GetFirstCollisionPosition(CONTACT_DISTANCE, target->GetRelativeAngle(m_caster));
+                    float objSize = target->GetObjectSize();
+                    float range = m_spellInfo->GetMaxRange(true, m_caster, this) * 1.5f + objSize; // can't be overly strict
 
-                    //first try with raycast, if it fails fall back to normal path
-                    m_preGeneratedPath.SetPathLengthLimit(m_spellInfo->GetMaxRange(true) * 1.5f);
-                    bool result = m_preGeneratedPath.CalculatePath(pos.m_positionX, pos.m_positionY, pos.m_positionZ + target->GetObjectSize(), false, true);
+                    m_preGeneratedPath.SetPathLengthLimit(range);
+                    // first try with raycast, if it fails fall back to normal path
+                    bool result = m_preGeneratedPath.CalculatePath(target->GetPositionX(), target->GetPositionY(), target->GetPositionZ() + target->GetObjectSize(), false, true);
                     if (m_preGeneratedPath.GetPathType() & PATHFIND_SHORT)
                         return SPELL_FAILED_OUT_OF_RANGE;
                     else if (!result || m_preGeneratedPath.GetPathType() & PATHFIND_NOPATH)
                     {
-                        result = m_preGeneratedPath.CalculatePath(pos.m_positionX, pos.m_positionY, pos.m_positionZ + target->GetObjectSize(), false, false);
+                        result = m_preGeneratedPath.CalculatePath(target->GetPositionX(), target->GetPositionY(), target->GetPositionZ() + target->GetObjectSize(), false, false);
                         if (m_preGeneratedPath.GetPathType() & PATHFIND_SHORT)
                             return SPELL_FAILED_OUT_OF_RANGE;
                         else if (!result || m_preGeneratedPath.GetPathType() & PATHFIND_NOPATH)
                             return SPELL_FAILED_NOPATH;
                     }
+
+                    m_preGeneratedPath.ReducePathLenghtByDist(objSize); // move back
                 }
                 break;
             }