AC:NH turnip price calculator

TurnipPrices.cpp

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>


// munged from https://github.com/simontime/Resead

namespace sead
{
class Random
{
public:
  void init();
  void init(uint32_t seed);
  void init(uint32_t seed1, uint32_t seed2, uint32_t seed3, uint32_t seed4);
  uint32_t getU32();
  uint64_t getU64();
  void getContext(uint32_t *seed1, uint32_t *seed2, uint32_t *seed3, uint32_t *seed4) const;

private:
  uint32_t mContext[4];
};

void Random::init()
{
  init(42069);
}

void Random::init(uint32_t seed)
{
  mContext[0] = 0x6C078965 * (seed ^ (seed >> 30)) + 1;
  mContext[1] = 0x6C078965 * (mContext[0] ^ (mContext[0] >> 30)) + 2;
  mContext[2] = 0x6C078965 * (mContext[1] ^ (mContext[1] >> 30)) + 3;
  mContext[3] = 0x6C078965 * (mContext[2] ^ (mContext[2] >> 30)) + 4;
}

void Random::init(uint32_t seed1, uint32_t seed2, uint32_t seed3, uint32_t seed4)
{
  if ((seed1 | seed2 | seed3 | seed4) == 0) // seeds must not be all zero.
  {
    seed1 = 1;
    seed2 = 0x6C078967;
    seed3 = 0x714ACB41;
    seed4 = 0x48077044;
  }

  mContext[0] = seed1;
  mContext[1] = seed2;
  mContext[2] = seed3;
  mContext[3] = seed4;
}

uint32_t Random::getU32()
{
  uint32_t n = mContext[0] ^ (mContext[0] << 11);

  mContext[0] = mContext[1];
  mContext[1] = mContext[2];
  mContext[2] = mContext[3];
  mContext[3] = n ^ (n >> 8) ^ mContext[3] ^ (mContext[3] >> 19);

  return mContext[3];
}

uint64_t Random::getU64()
{
  uint32_t n1 = mContext[0] ^ (mContext[0] << 11);
  uint32_t n2 = mContext[1];
  uint32_t n3 = n1 ^ (n1 >> 8) ^ mContext[3];

  mContext[0] = mContext[2];
  mContext[1] = mContext[3];
  mContext[2] = n3 ^ (mContext[3] >> 19);
  mContext[3] = n2 ^ (n2 << 11) ^ ((n2 ^ (n2 << 11)) >> 8) ^ mContext[2] ^ (n3 >> 19);

  return ((uint64_t)mContext[2] << 32) | mContext[3];
}

void Random::getContext(uint32_t *seed1, uint32_t *seed2, uint32_t *seed3, uint32_t *seed4) const
{
  *seed1 = mContext[0];
  *seed2 = mContext[1];
  *seed3 = mContext[2];
  *seed4 = mContext[3];
}
} // namespace sead

uint32_t pf(float f) {
  return *((uint32_t *)&f);
}
struct TurnipPrices
{
  int32_t basePrice;
  int32_t sellPrices[14];
  uint32_t whatPattern;
  int32_t tmp40;

  void calculate();

  // utility stuff for testing
  sead::Random rng;
  bool randbool()
  {
    return rng.getU32() & 0x80000000;
  }
  int randint(int min, int max)
  {
    return (((uint64_t)rng.getU32() * (uint64_t)(max - min + 1)) >> 32) + min;
  }
  float randfloat(float a, float b)
  {
    uint32_t val = 0x3F800000 | (rng.getU32() >> 9);
    float fval = *(float *)(&val);
    return a + ((fval - 1.0f) * (b - a));
  }
  float randfloatMockedLeft(float a, float b)
  {
    uint32_t val = 0x3F800000 | (0 >> 9);
    float fval = *(float *)(&val);
    return a + ((fval - 1.0f) * (b - a));
  }
  float randfloatMockedRight(float a, float b)
  {
    uint32_t val = 0x3F800000 | (UINT32_MAX >> 9);
    float fval = *(float *)(&val);
    return a + ((fval - 1.0f) * (b - a));
  }     
  float randfloatMockedMin(float a, float b)
  {
    return std::min(randfloatMockedLeft(a, b), randfloatMockedRight(a, b));
  }
  float randfloatMockedMax(float a, float b)
  {
    return std::max(randfloatMockedLeft(a, b), randfloatMockedRight(a, b));
  }    
  int intceil(float val)
  {
    return (int)(val + 0.99999f);
  }
};

void TurnipPrices::calculate()
{
  basePrice = randint(90, 110);
  int chance = randint(0, 99);

  // select the next pattern
  int nextPattern;

  if (whatPattern >= 4)
  {
    nextPattern = 2;
  }
  else
  {
    switch (whatPattern)
    {
    case 0:
      if (chance < 20)
      {
        nextPattern = 0;
      }
      else if (chance < 50)
      {
        nextPattern = 1;
      }
      else if (chance < 65)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 1:
      if (chance < 50)
      {
        nextPattern = 0;
      }
      else if (chance < 55)
      {
        nextPattern = 1;
      }
      else if (chance < 75)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 2:
      if (chance < 25)
      {
        nextPattern = 0;
      }
      else if (chance < 70)
      {
        nextPattern = 1;
      }
      else if (chance < 75)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    case 3:
      if (chance < 45)
      {
        nextPattern = 0;
      }
      else if (chance < 70)
      {
        nextPattern = 1;
      }
      else if (chance < 85)
      {
        nextPattern = 2;
      }
      else
      {
        nextPattern = 3;
      }
      break;
    }
  }

  whatPattern = nextPattern;

  /*
  if (checkGlobalFlag("FirstKabuBuy")) {
    if (!checkGlobalFlag("FirstKabuPattern")) {
      setGlobalFlag("FirstKabuPattern", true);
      whatPattern = 3;
    }
  }
  */

  for (int i = 2; i < 14; i++)
    sellPrices[i] = 0;
  sellPrices[0] = basePrice;
  sellPrices[1] = basePrice;

  int work;
  int decPhaseLen1, decPhaseLen2, peakStart;
  int hiPhaseLen1, hiPhaseLen2and3, hiPhaseLen3;
  float rate;

  switch (whatPattern)
  {
  case 0:
    // PATTERN 0: high, decreasing, high, decreasing, high
    work = 2;
    decPhaseLen1 = randbool() ? 3 : 2;
    decPhaseLen2 = 5 - decPhaseLen1;

    hiPhaseLen1 = randint(0, 6);
    hiPhaseLen2and3 = 7 - hiPhaseLen1;
    hiPhaseLen3 = randint(0, hiPhaseLen2and3 - 1);

    // high phase 1
    for (int i = 0; i < hiPhaseLen1; i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }

    // decreasing phase 1
    rate = randfloat(0.8, 0.6);
    for (int i = 0; i < decPhaseLen1; i++)
    {
      sellPrices[work++] = intceil(rate * basePrice);
      rate -= 0.04;
      rate -= randfloat(0, 0.06);
    }

    // high phase 2
    for (int i = 0; i < (hiPhaseLen2and3 - hiPhaseLen3); i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }

    // decreasing phase 2
    rate = randfloat(0.8, 0.6);
    for (int i = 0; i < decPhaseLen2; i++)
    {
      sellPrices[work++] = intceil(rate * basePrice);
      rate -= 0.04;
      rate -= randfloat(0, 0.06);
    }

    // high phase 3
    for (int i = 0; i < hiPhaseLen3; i++)
    {
      sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    }
    break;
  case 1:
    // PATTERN 1: decreasing middle, high spike, random low
    peakStart = randint(3, 9);
    rate = randfloat(0.9, 0.85);
    for (work = 2; work < peakStart; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, 2.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(2.0, 6.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, 2.0) * basePrice);
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    for (; work < 14; work++)
    {
      sellPrices[work] = intceil(randfloat(0.4, 0.9) * basePrice);
    }
    break;
  case 2:
    // PATTERN 2: consistently decreasing
    rate = 0.9;
    rate -= randfloat(0, 0.05);
    for (work = 2; work < 14; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }
    break;
  case 3:
    // PATTERN 3: decreasing, spike, decreasing
    peakStart = randint(2, 9);

    // decreasing phase before the peak
    rate = randfloat(0.9, 0.4);
    for (work = 2; work < peakStart; work++)
    {
      sellPrices[work] = intceil(rate * basePrice);
      rate -= 0.03;
      rate -= randfloat(0, 0.02);
    }

    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * (float)basePrice);
    sellPrices[work++] = intceil(randfloat(0.9, 1.4) * basePrice);
    rate = randfloat(1.4, 2.0);
    sellPrices[work++] = intceil(randfloat(1.4, rate) * basePrice) - 1;
    sellPrices[work++] = intceil(rate * basePrice);
    sellPrices[work++] = intceil(randfloat(1.4, rate) * basePrice) - 1;

    // decreasing phase after the peak
    if (work < 14)
    {
      rate = randfloat(0.9, 0.4);
      for (; work < 14; work++)
      {
        sellPrices[work] = intceil(rate * basePrice);
        rate -= 0.03;
        rate -= randfloat(0, 0.02);
      }
    }
    break;
  }

  sellPrices[0] = 0;
  sellPrices[1] = 0;
}

int main(int argc, char **argv)
{
  TurnipPrices turnips;
  turnips.rng.init();

  float checkingMin = turnips.randfloatMockedMin(1000.0, 2000.0),
        checkingMax = turnips.randfloatMockedMax(1000.0, 2000.0);

  printf("checkingMin, checkingMax are %f %f   exact? %d %d\n", checkingMin, checkingMax, checkingMin == 1000.0, checkingMax == 2000.0);  

  checkingMin = turnips.randfloatMockedMin(2000.0, 1000.0),
        checkingMax = turnips.randfloatMockedMax(2000.0, 1000.0);

  printf("checkingMin, checkingMax are %f %f   exact? %d %d\n", checkingMin, checkingMax, checkingMin == 1000.0, checkingMax == 2000.0);  

  float rateLow = turnips.randfloatMockedMin(0.9, 0.85);
  float rateHigh = turnips.randfloatMockedMax(0.9, 0.85);

  for (int work = 2; work < 6; work++)  {
    int priceMin = 999999, priceMax = 0;
    int priceLow, priceHigh;

    for (int basePrice = 90; basePrice <= 110; basePrice++) {   // could have added 20 directly
      priceLow = turnips.intceil(rateLow * basePrice);
      priceHigh = turnips.intceil(rateHigh * basePrice);

      priceMin = std::min(priceLow, priceMin);
      priceMax = std::max(priceHigh, priceMax);
    }

    printf("PRICE period %d   low %d   high %d\n", work, priceMin, priceMax);

    rateLow -= 0.03;
    rateHigh -= 0.03;

    rateLow -= turnips.randfloatMockedMax(0, 0.02);
    rateHigh -= turnips.randfloatMockedMin(0, 0.02);
  }


  return 0;
}

So I tried the first 4 periods:

checkingMin, checkingMax are 1000.000000 1999.999878   exact? 1 0
checkingMin, checkingMax are 1000.000122 2000.000000   exact? 0 1
PRICE period 2   low 77   high 99
PRICE period 3   low 73   high 96
PRICE period 4   low 68   high 93
PRICE period 5   low 64   high 90

So if period 5 above has a value of 63, it cannot be the high spike pattern.