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

#include "camera.h"
#include "transformations.h"
#include "runner.h"

static bool camera_test_0(const char ** scenario)
{
  *scenario = "Constructing a camera";

  float hsize = 160.0f;
  float vsize = 120.0f;
  float field_of_view = pi / 2.0f;

  struct camera c = camera(hsize, vsize, field_of_view);

  struct mat4x4 identity_matrix = mat4x4_identity();

  return
    float_equal(c.hsize, 160.0f) &&
    float_equal(c.vsize, 120.0f) &&
    float_equal(c.field_of_view, pi / 2.0f) &&
    mat4x4_equal(&c.transform, &identity_matrix);
}

static bool camera_test_1(const char ** scenario)
{
  *scenario = "The pixel size for a horizontal camera";

  struct camera c = camera(200.0f, 125.0f, pi / 2.0f);

  return float_equal(c.pixel_size, 0.01f);
}

static bool camera_test_2(const char ** scenario)
{
  *scenario = "The pixel size for a vertical camera";

  struct camera c = camera(125.0f, 200.0f, pi / 2.0f);

  return float_equal(c.pixel_size, 0.01f);
}

static bool camera_test_3(const char ** scenario)
{
  *scenario = "Constructing a ray through the center of the canvas";

  struct camera c = camera(201.0f, 101.0f, pi / 2.0f);
  struct ray r = camera_ray_for_pixel(&c, 100.0f, 50.0f);

  return
    tuple_equal(r.origin, point(0.0f, 0.0f, 0.0f)) &&
    tuple_equal(r.direction, vector(0.0f, 0.0f, -1.0f));
}

static bool camera_test_4(const char ** scenario)
{
  *scenario = "Constructing a ray through the corner of the canvas";

  struct camera c = camera(201.0f, 101.0f, pi / 2.0f);
  struct ray r = camera_ray_for_pixel(&c, 0.0f, 0.0f);

  return
    tuple_equal(r.origin, point(0.0f, 0.0f, 0.0f)) &&
    tuple_equal(r.direction, vector(0.66519f, 0.33259f, -0.66851f));
}

static bool camera_test_5(const char ** scenario)
{
  *scenario = "Constructing a ray when the camera is transformed";

  struct camera c = camera(201.0f, 101.0f, pi / 2.0f);
  struct mat4x4 rotate = rotation_y(pi / 4.0f);
  struct mat4x4 translate = translation(0.0f, -2.0f, 5.0f);
  c.transform = mat4x4_mul_m(&rotate, &translate);
  struct ray r = camera_ray_for_pixel(&c, 100.0f, 50.0f);

  return
    tuple_equal(r.origin, point(0.0f, 2.0f, -5.0f)) &&
    tuple_equal(r.direction, vector(0.7071067811865476f, 0.0f, -0.7071067811865476f));
}

static bool camera_test_6(const char ** scenario)
{
  *scenario = "Rendering a world with a camera";

  struct world w = default_world();
  struct camera c = camera(11.0f, 11.0f, pi / 2.0f);
  struct tuple from = point(0.0f, 0.0f, -5.0f);
  struct tuple to = point(0.0f, 0.0f, 0.0f);
  struct tuple up = vector(0.0f, 1.0f, 0.0f);
  c.transform = view_transform(from, to, up);
  struct canvas image;
  camera_render(&c, &w, &image);

  struct tuple col = canvas_pixel_at(&image, 5, 5);
  return
    tuple_equal(col, color(0.38066, 0.47583, 0.2855));
}

test_t camera_tests[] = {
  camera_test_0,
  camera_test_1,
  camera_test_2,
  camera_test_3,
  camera_test_4,
  camera_test_5,
  camera_test_6,
};

RUNNER(camera_tests)