#include <stdbool.h>
#include <stdio.h>

#include "rays.h"
#include "planes.h"
#include "intersections_shapes.h"
#include "runner.h"
#include "matrices.h"
#include "transformations.h"

static bool planes_test_0(const char ** scenario)
{
  *scenario = "The normal of a plane is constant everywhere";

  struct tuple n1 = plane_normal_at(point(0.0f, 0.0f, 0.0f));
  struct tuple n2 = plane_normal_at(point(10.0f, 0.0f, -10.0f));
  struct tuple n3 = plane_normal_at(point(-5.0f, 0.0f, 150.0f));
  return
    tuple_equal(n1, vector(0.0f, 1.0f, 0.0f)) &&
    tuple_equal(n2, vector(0.0f, 1.0f, 0.0f)) &&
    tuple_equal(n3, vector(0.0f, 1.0f, 0.0f));
}

static bool planes_test_1(const char ** scenario)
{
  *scenario = "Intersect with a ray parallel to the plane";

  struct shape p = plane();
  struct ray r = ray(point(0.0f, 10.0f, 0.0f), vector(0.0f, 0.0f, 1.0f));
  struct intersections xs;
  xs.count = 0;
  plane_intersect(&p, r, &xs);
  return xs.count == 0;
}

static bool planes_test_2(const char ** scenario)
{
  *scenario = "Intersect with a coplanar ray";

  struct shape p = plane();
  struct ray r = ray(point(0.0f, 0.0f, 0.0f), vector(0.0f, 0.0f, 1.0f));
  struct intersections xs;
  xs.count = 0;
  plane_intersect(&p, r, &xs);
  return xs.count == 0;
}

static bool planes_test_3(const char ** scenario)
{
  *scenario = "A ray intersecting a plane from above";

  struct shape p = plane();
  struct ray r = ray(point(0.0f, 1.0f, 0.0f), vector(0.0f, -1.0f, 0.0f));
  struct intersections xs;
  xs.count = 0;
  plane_intersect(&p, r, &xs);
  return
    xs.count == 1 &&
    float_equal(xs.i[0].t, 1.0f) &&
    xs.i[0].object == &p;
}

static bool planes_test_4(const char ** scenario)
{
  *scenario = "A ray intersecting a plane from below";

  struct shape p = plane();
  struct ray r = ray(point(0.0f, -1.0f, 0.0f), vector(0.0f, 1.0f, 1.0f));
  struct intersections xs;
  xs.count = 0;
  plane_intersect(&p, r, &xs);
  return
    xs.count == 1 &&
    float_equal(xs.i[0].t, 1.0f) &&
    xs.i[0].object == &p;
}

test_t planes_tests[] = {
  planes_test_0,
  planes_test_1,
  planes_test_2,
  planes_test_3,
  planes_test_4,
};

RUNNER(planes_tests);