LimitValue.h

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// SPDX-FileCopyrightText: Deutsches Elektronen-Synchrotron DESY, MSK, ChimeraTK Project <chimeratk-support@desy.de>
// SPDX-License-Identifier: LGPL-3.0-or-later
#pragma once
 
#include "ApplicationModule.h"
#include "ScalarAccessor.h"
 
namespace ChimeraTK {
 
  template<typename UserType>
  struct LimitValueModuleBase : public ApplicationModule {
    using ApplicationModule::ApplicationModule;
 
    ScalarPushInput<UserType> input{this, "input", "", "The input value to be limited into the range."};
    ScalarOutput<UserType> output{this, "output", "", "The output value after limiting."};
    ScalarOutput<int> isLimited{
        this, "isLimited", "", "Boolean set to true if the value was limited and to false otherwise."};
 
    void applyLimit(UserType min, UserType max) {
      bool wasLimited = isLimited;
 
      // clamp input value into given range
      UserType value = input;
      if(value > max) {
        output = max;
        isLimited = true;
      }
      else if(value < min) {
        output = min;
        isLimited = true;
      }
      else {
        output = value;
        isLimited = false;
      }
 
      // write output. isLimited is only written when changed
      output.write();
      if(isLimited != wasLimited) isLimited.write();
      wasLimited = isLimited;
    }
  };
 
  template<typename UserType>
  struct LimitValue : public LimitValueModuleBase<UserType> {
    using LimitValueModuleBase<UserType>::LimitValueModuleBase;
    ScalarPushInput<UserType> min{this, "min", "", "The minimum allowed value."};
    ScalarPushInput<UserType> max{this, "max", "", "The maximum allowed value."};
    using LimitValueModuleBase<UserType>::input;
    using LimitValueModuleBase<UserType>::applyLimit;
 
    void mainLoop() {
      auto readGroup = this->readAnyGroup();
      while(true) {
        applyLimit(min, max);
        // wait for new input values (at the end, since we want to process the
        // initial values first)
        readGroup.readAny();
      }
    }
  };
 
  template<typename UserType, UserType min, UserType max>
  struct FixedLimitValue : public LimitValueModuleBase<UserType> {
    using LimitValueModuleBase<UserType>::LimitValueModuleBase;
    using LimitValueModuleBase<UserType>::input;
    using LimitValueModuleBase<UserType>::applyLimit;
 
    void mainLoop() {
      while(true) {
        applyLimit(min, max);
        // wait for new input values (at the end, since we want to process the
        // initial values first)
        input.read();
      }
    }
  };
 
} // namespace ChimeraTK