/* SPDX-License-Identifier: Apache-2.0
 * Copyright 2011-2022 Blender Foundation */

#include "stdcycles.h"

/* Checker */

float checker(point ip)
{
  point p;
  p[0] = (ip[0] + 0.000001) * 0.999999;
  p[1] = (ip[1] + 0.000001) * 0.999999;
  p[2] = (ip[2] + 0.000001) * 0.999999;

  int xi = (int)fabs(floor(p[0]));
  int yi = (int)fabs(floor(p[1]));
  int zi = (int)fabs(floor(p[2]));

  if ((xi % 2 == yi % 2) == (zi % 2)) {
    return 1.0;
  }
  else {
    return 0.0;
  }
}

shader node_checker_texture(
    int use_mapping = 0,
    matrix mapping = matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),
    float Scale = 5.0,
    point Vector = P,
    color Color1 = 0.8,
    color Color2 = 0.2,
    output float Fac = 0.0,
    output color Color = 0.0)
{
  point p = Vector;

  if (use_mapping)
    p = transform(mapping, p);

  Fac = checker(p * Scale);
  if (Fac == 1.0) {
    Color = Color1;
  }
  else {
    Color = Color2;
  }
}