#include <math/mat4.h>

#include <math/float.h>

#include "test.h"

#include <stdio.h>

static const float eps = 1e-9;

static inline void print_mat4(mat4 m) {
  printf("\n");
  for (int i = 0; i < 4; ++i) {
    for (int j = 0; j < 4; ++j) {
      printf("%6.3f  ", mat4_at(m, i, j));
    }
    printf("\n");
  }
}

TEST_CASE(lookat_right) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(1, 0, 0),
                             /*up=*/vec3_make(0, 1, 0));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {0, 0, 1, 0},
      {0, 1, 0, 0},
      {1, 0, 0, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

TEST_CASE(lookat_left) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(-1, 0, 0),
                             /*up=*/vec3_make(0, 1, 0));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {0, 0, -1, 0},
      {0, 1, 0, 0},
      {-1, 0, 0, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

TEST_CASE(lookat_up) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(0, 1, 0),
                             /*up=*/vec3_make(0, 0, 1));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {1, 0, 0, 0},
      {0, 0, 1, 0},
      {0, 1, 0, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

TEST_CASE(lookat_down) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(0, -1, 0),
                             /*up=*/vec3_make(0, 0, -1));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {1, 0, 0, 0},
      {0, 0, -1, 0},
      {0, -1, 0, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

TEST_CASE(lookat_forward) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(0, 0, -1),
                             /*up=*/vec3_make(0, 1, 0));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {1, 0, 0, 0},
      {0, 1, 0, 0},
      {0, 0, -1, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

TEST_CASE(lookat_back) {
  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
                             /*target=*/vec3_make(0, 0, 1),
                             /*up=*/vec3_make(0, 1, 0));

  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
      {-1, 0, 0, 0},
      {0, 1, 0, 0},
      {0, 0, 1, 0},
      {0, 0, 0, 1},
  });

  TEST_TRUE(mat4_eq(m, expected, eps));
}

int main() { return 0; }