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/* Copyright (C) 2012 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#include "precompiled.h"
#include "simulation2/system/Component.h"
#include "ICmpMotion.h"
#include "ICmpPosition.h"
#include "simulation2/MessageTypes.h"
#include "graphics/Terrain.h"
class CCmpMotionBall : public ICmpMotion
{
public:
static void ClassInit(CComponentManager& componentManager)
{
componentManager.SubscribeToMessageType(MT_Update);
}
DEFAULT_COMPONENT_ALLOCATOR(MotionBall)
// Current speed in metres per second
float m_SpeedX, m_SpeedZ;
static std::string GetSchema()
{
return "<a:component type='test'/><ref name='anything'/>";
}
virtual void Init(const CParamNode& UNUSED(paramNode))
{
m_SpeedX = 0;
m_SpeedZ = 0;
}
virtual void Deinit()
{
}
virtual void Serialize(ISerializer& serialize)
{
serialize.NumberFloat_Unbounded("speed x", m_SpeedX);
serialize.NumberFloat_Unbounded("speed z", m_SpeedZ);
}
virtual void Deserialize(const CParamNode& paramNode, IDeserializer& deserialize)
{
Init(paramNode);
deserialize.NumberFloat_Unbounded("speed x", m_SpeedX);
deserialize.NumberFloat_Unbounded("speed z", m_SpeedZ);
}
virtual void HandleMessage(const CMessage& msg, bool UNUSED(global))
{
switch (msg.GetType())
{
case MT_Update:
{
fixed dt = static_cast<const CMessageUpdate&> (msg).turnLength;
Move(dt);
break;
}
}
}
void Move(fixed dt);
};
void CCmpMotionBall::Move(fixed dt)
{
CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
if (!cmpPosition)
return;
// TODO: this is all FP-unsafe
CFixedVector3D pos = cmpPosition->GetPosition();
float x = pos.X.ToFloat();
float z = pos.Z.ToFloat();
CVector3D normal = GetSimContext().GetTerrain().CalcExactNormal(x, z);
// Flatten the vector, to get the downhill force
float g = 10.f;
CVector3D force(g * normal.X, 0.f, g * normal.Z);
m_SpeedX += force.X;
m_SpeedZ += force.Z;
float drag = 0.5f; // fractional decay per second
float dt_ = dt.ToFloat();
m_SpeedX *= powf(drag, dt_);
m_SpeedZ *= powf(drag, dt_);
cmpPosition->MoveTo(entity_pos_t::FromFloat(x + m_SpeedX * dt_), entity_pos_t::FromFloat(z + m_SpeedZ * dt_));
}
REGISTER_COMPONENT_TYPE(MotionBall)
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