real_world_dataset/custom_source/pathtracing.c

#include <math.h>
#include <stdio.h>

float fresnelReflectanceAtNormal_f(float index) {
  float partial = (1.0f - index) / (1.0f + index);
  return partial * partial;
}

double fresnelReflectanceAtNormal_d(double index) {
  double partial = (1.0 - index) / (1.0 + index);
  return partial * partial;
}

float blinToBeckmann_f(float alpha) {
  return sqrtf(2.0f / (alpha + 2.0f));
}

float beckmannToBlinn_f(float slope) {
  return 2.0f / (slope * slope) - 2.0f;
}

double blinToBeckmann_d(double alpha) {
  return sqrtf(2.0 / (alpha + 2.0));
}

double beckmannToBlinn_d(double slope) {
  return 2.0 / (slope * slope) - 2.0;
}

int main() {
    float xf;
    double xd;
    int l;

    l = scanf("%f", &xf);
    l = scanf("%lf", &xd);

    printf("%f\n",  fresnelReflectanceAtNormal_f(xf));
    printf("%lf\n", fresnelReflectanceAtNormal_d(xd));

    printf("%f\n",  blinToBeckmann_f(xf));
    printf("%lf\n", blinToBeckmann_d(xd));

    printf("%f\n",  beckmannToBlinn_f(xf));
    printf("%lf\n", beckmannToBlinn_d(xd));
}