Line data    Source code

       1             : /* Copyright (C) 2022 Wildfire Games.
       2             :  * This file is part of 0 A.D.
       3             :  *
       4             :  * 0 A.D. is free software: you can redistribute it and/or modify
       5             :  * it under the terms of the GNU General Public License as published by
       6             :  * the Free Software Foundation, either version 2 of the License, or
       7             :  * (at your option) any later version.
       8             :  *
       9             :  * 0 A.D. is distributed in the hope that it will be useful,
      10             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12             :  * GNU General Public License for more details.
      13             :  *
      14             :  * You should have received a copy of the GNU General Public License
      15             :  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
      16             :  */
      17             : 
      18             : #include "precompiled.h"
      19             : 
      20             : #include "simulation2/system/Component.h"
      21             : #include "ICmpMotion.h"
      22             : 
      23             : #include "ICmpPosition.h"
      24             : #include "simulation2/MessageTypes.h"
      25             : 
      26             : #include "graphics/Terrain.h"
      27             : 
      28           0 : class CCmpMotionBall final : public ICmpMotion
      29             : {
      30             : public:
      31         116 :     static void ClassInit(CComponentManager& componentManager)
      32             :     {
      33         116 :         componentManager.SubscribeToMessageType(MT_Update);
      34         116 :     }
      35             : 
      36           0 :     DEFAULT_COMPONENT_ALLOCATOR(MotionBall)
      37             : 
      38             :     // Current speed in metres per second
      39             :     float m_SpeedX, m_SpeedZ;
      40             : 
      41         116 :     static std::string GetSchema()
      42             :     {
      43         116 :         return "<a:component type='test'/><ref name='anything'/>";
      44             :     }
      45             : 
      46           0 :     void Init(const CParamNode& UNUSED(paramNode)) override
      47             :     {
      48           0 :         m_SpeedX = 0;
      49           0 :         m_SpeedZ = 0;
      50           0 :     }
      51             : 
      52           0 :     void Deinit() override
      53             :     {
      54           0 :     }
      55             : 
      56           0 :     void Serialize(ISerializer& serialize) override
      57             :     {
      58           0 :         serialize.NumberFloat_Unbounded("speed x", m_SpeedX);
      59           0 :         serialize.NumberFloat_Unbounded("speed z", m_SpeedZ);
      60           0 :     }
      61             : 
      62           0 :     void Deserialize(const CParamNode& paramNode, IDeserializer& deserialize) override
      63             :     {
      64           0 :         Init(paramNode);
      65           0 :         deserialize.NumberFloat_Unbounded("speed x", m_SpeedX);
      66           0 :         deserialize.NumberFloat_Unbounded("speed z", m_SpeedZ);
      67           0 :     }
      68             : 
      69           0 :     void HandleMessage(const CMessage& msg, bool UNUSED(global)) override
      70             :     {
      71           0 :         switch (msg.GetType())
      72             :         {
      73           0 :         case MT_Update:
      74             :         {
      75           0 :             fixed dt = static_cast<const CMessageUpdate&> (msg).turnLength;
      76           0 :             Move(dt);
      77           0 :             break;
      78             :         }
      79             :         }
      80           0 :     }
      81             : 
      82             :     void Move(fixed dt);
      83             : };
      84             : 
      85           0 : void CCmpMotionBall::Move(fixed dt)
      86             : {
      87           0 :     CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
      88           0 :     if (!cmpPosition)
      89           0 :         return;
      90             : 
      91             :     // TODO: this is all FP-unsafe
      92             : 
      93           0 :     CFixedVector3D pos = cmpPosition->GetPosition();
      94           0 :     float x = pos.X.ToFloat();
      95           0 :     float z = pos.Z.ToFloat();
      96             : 
      97           0 :     CVector3D normal = GetSimContext().GetTerrain().CalcExactNormal(x, z);
      98             :     // Flatten the vector, to get the downhill force
      99           0 :     float g = 10.f;
     100           0 :     CVector3D force(g * normal.X, 0.f, g * normal.Z);
     101             : 
     102           0 :     m_SpeedX += force.X;
     103           0 :     m_SpeedZ += force.Z;
     104             : 
     105           0 :     float drag = 0.5f; // fractional decay per second
     106             : 
     107           0 :     float dt_ = dt.ToFloat();
     108             : 
     109           0 :     m_SpeedX *= powf(drag, dt_);
     110           0 :     m_SpeedZ *= powf(drag, dt_);
     111             : 
     112           0 :     cmpPosition->MoveTo(entity_pos_t::FromFloat(x + m_SpeedX * dt_), entity_pos_t::FromFloat(z + m_SpeedZ * dt_));
     113             : }
     114             : 
     115         119 : REGISTER_COMPONENT_TYPE(MotionBall)