// Automatically generated C++ file on Tue Nov  5 19:12:22 2024
//
// To build with Digital Mars C++ Compiler:
//
//    dmc -mn -WD constantontime.cpp kernel32.lib

#include <malloc.h>

extern "C" __declspec(dllexport) int (*Display)(const char *format, ...) = 0; // works like printf()
extern "C" __declspec(dllexport) const double *DegreesC                  = 0; // pointer to current circuit temperature
extern "C" __declspec(dllexport) const int *StepNumber                   = 0; // pointer to current step number
extern "C" __declspec(dllexport) const int *NumberSteps                  = 0; // pointer to estimated number of steps
extern "C" __declspec(dllexport) const char* const *InstanceName         = 0; // pointer to address of instance name
extern "C" __declspec(dllexport) const char *QUX                         = 0; // path to QUX.exe
extern "C" __declspec(dllexport) const bool *ForKeeps                    = 0; // pointer to whether being evaluated non-hypothetically
extern "C" __declspec(dllexport) const bool *HoldICs                     = 0; // pointer to whether instance initial conditions are being held
extern "C" __declspec(dllexport) int (*DFFT)(struct sComplex *u, bool inv, unsigned int N, double scale) = 0; // discrete Fast Fourier function

union uData
{
   bool b;
   char c;
   unsigned char uc;
   short s;
   unsigned short us;
   int i;
   unsigned int ui;
   float f;
   double d;
   long long int i64;
   unsigned long long int ui64;
   char *str;
   unsigned char *bytes;
};

// int DllMain() must exist and return 1 for a process to load the .DLL
// See https://docs.microsoft.com/en-us/windows/win32/dlls/dllmain for more information.
int __stdcall DllMain(void *module, unsigned int reason, void *reserved) { return 1; }

void bzero(void *ptr, unsigned int count)
{
   unsigned char *first = (unsigned char *) ptr;
   unsigned char *last  = first + count;
   while(first < last)
      *first++ = '\0';
}

// #undef pin names lest they collide with names in any header file(s) you might include.
#undef CLK
#undef Q
#undef Ton

struct sCONSTANTONTIME
{
  // declare the structure here
  bool lastQ;
  bool lastCLK;
  float Tclk;
};

extern "C" __declspec(dllexport) void constantontime(struct sCONSTANTONTIME **opaque, double t, union uData *data)
{
   bool   CLK = data[0].b; // input
   double Ton = data[1].d; // input
   bool  &Q   = data[2].b; // output

   if(!*opaque)
   {
      *opaque = (struct sCONSTANTONTIME *) malloc(sizeof(struct sCONSTANTONTIME));
      bzero(*opaque, sizeof(struct sCONSTANTONTIME));
   }
   struct sCONSTANTONTIME *inst = *opaque;

// Implement module evaluation code here:

   // rising edge : Set Q
   if ( (CLK != inst->lastCLK) & (CLK) ){
      Q = 1;
      inst->Tclk = t;   // record time of rising edge to inst->Tclk
   }

   // On time more than Ton (external) : Reset Q
   float OnTime = t - inst->Tclk;   // on time duration
   if ( OnTime > Ton ){
      Q = 0;
   }

   // Store current state
   inst->lastQ = Q;
   inst->lastCLK = CLK;
}

extern "C" __declspec(dllexport) double MaxExtStepSize(struct sCONSTANTONTIME *inst)
{
   return 1e308; // implement a good choice of max timestep size that depends on struct sCONSTANTONTIME
}

extern "C" __declspec(dllexport) void Trunc(struct sCONSTANTONTIME *inst, double t, union uData *data, double *timestep)
{ // limit the timestep to a tolerance if the circuit causes a change in struct sCONSTANTONTIME
   const double ttol = 1e-9; // 1ns default tolerance
   if(*timestep > ttol)
   {
      struct sCONSTANTONTIME tmp = *inst;
      constantontime(&(&tmp), t, data);
   // if(tmp != *inst) // implement a meaningful way to detect if the state has changed
   //    *timestep = ttol;
      if (tmp.lastQ != inst->lastQ)
         *timestep = ttol;
   }
}

extern "C" __declspec(dllexport) void Destroy(struct sCONSTANTONTIME *inst)
{
   free(inst);
}