Line data    Source code

       1             : /* Copyright (C) 2019 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 <cmath>
      21             : 
      22             : #include "graphics/SmoothedValue.h"
      23             : 
      24           0 : CSmoothedValue::CSmoothedValue(float value, float smoothness, float minDelta)
      25             :     : m_Target(value),
      26             :       m_Current(value),
      27             :       m_Smoothness(smoothness),
      28           0 :       m_MinDelta(minDelta)
      29             : {
      30           0 : }
      31             : 
      32           0 : float CSmoothedValue::Update(float time)
      33             : {
      34           0 :     if (fabs(m_Target - m_Current) < m_MinDelta)
      35           0 :         return 0.0f;
      36             : 
      37           0 :     double p = pow(static_cast<double>(m_Smoothness), 10.0 * static_cast<double>(time));
      38             :     // (add the factor of 10 so that smoothnesses don't have to be tiny numbers)
      39             : 
      40           0 :     double delta = (m_Target - m_Current) * (1.0 - p);
      41           0 :     m_Current += delta;
      42           0 :     return static_cast<float>(delta);
      43             : }
      44             : 
      45           0 : void CSmoothedValue::Wrap(float min, float max)
      46             : {
      47           0 :     double t = fmod(m_Target - min, static_cast<double>(max - min));
      48           0 :     if (t < 0)
      49           0 :         t += max - min;
      50           0 :     t += min;
      51             : 
      52           0 :     m_Current += t - m_Target;
      53           0 :     m_Target = t;
      54           3 : }