Line data    Source code

       1             : /* Copyright (C) 2021 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             : #ifndef INCLUDED_SMOOTHEDVALUE
      19             : #define INCLUDED_SMOOTHEDVALUE
      20             : 
      21             : #include "maths/MathUtil.h"
      22             : 
      23             : /**
      24             : * A value with exponential decay towards the target value.
      25             : */
      26             : class CSmoothedValue
      27             : {
      28             : public:
      29             :     CSmoothedValue(float value, float smoothness, float minDelta);
      30             : 
      31           0 :     float GetSmoothedValue() const
      32             :     {
      33           0 :         return m_Current;
      34             :     }
      35             : 
      36           0 :     void SetValueSmoothly(float value)
      37             :     {
      38           0 :         m_Target = value;
      39           0 :     }
      40             : 
      41           0 :     void AddSmoothly(float value)
      42             :     {
      43           0 :         m_Target += value;
      44           0 :     }
      45             : 
      46           0 :     void Add(float value)
      47             :     {
      48           0 :         m_Target += value;
      49           0 :         m_Current += value;
      50           0 :     }
      51             : 
      52           0 :     float GetValue() const
      53             :     {
      54           0 :         return m_Target;
      55             :     }
      56             : 
      57           0 :     void SetValue(float value)
      58             :     {
      59           0 :         m_Target = value;
      60           0 :         m_Current = value;
      61           0 :     }
      62             : 
      63           0 :     float GetSmoothness() const
      64             :     {
      65           0 :         return m_Smoothness;
      66             :     }
      67             : 
      68           0 :     void SetSmoothness(float smoothness)
      69             :     {
      70           0 :         m_Smoothness = smoothness;
      71           0 :     }
      72             : 
      73           0 :     void ClampSmoothly(float min, float max)
      74             :     {
      75           0 :         m_Target = Clamp<double>(m_Target, min, max);
      76           0 :     }
      77             : 
      78             :     float Update(float time);
      79             : 
      80             :     // Wrap so 'target' is in the range [min, max]
      81             :     void Wrap(float min, float max);
      82             : 
      83             : private:
      84             :     float m_Smoothness;
      85             : 
      86             :     double m_Target; // the value which m_Current is tending towards
      87             :     double m_Current;
      88             :     // (We use double because the extra precision is worthwhile here)
      89             : 
      90             :     float m_MinDelta; // cutoff where we stop moving (to avoid ugly shimmering effects)
      91             : };
      92             : 
      93             : #endif // INCLUDED_SMOOTHEDVALUE