Negative input values result in invalid noise result

[SenneW-2158088]

When using the function like:

  for (int x = -2; x < 2; x++) {

    for (int z = -2; z < 2; z++) {
      std::cout << "("<< x << ", " << z << ")" << std::endl;
      std::cout << db::perlin(x * 0.2f, z * 0.2f) << std::endl; 
    }
    std::cout << std::endl;
  }

this results in very high output noise values when there is a negative number involved:

(-2, -2)
-1.11151e+28
(-2, -1)
-1.10544e+28
(-2, 0)
1.68817e+15
(-2, 1)
1.39458e+15

(-1, -2)
-1.10803e+28
(-1, -1)
-1.10199e+28
(-1, 0)
1.68027e+15
(-1, 1)
1.38806e+15

(0, -2)
1.68158e+15
(0, -1)
1.67371e+15
(0, 0)
0
(0, 1)
-0.046336

(1, -2)
1.68227e+15
(1, -1)
1.67439e+15
(1, 0)
0.188416
(1, 1)
0.128483

[daniilsjb]

Hello! Sorry for not dealing with this issue sooner, I had busy several months. I fixed the problem, it was a small mistake specific to the 2D implementation of the noise. I decided to play around with adding an interactive visualization of the algorithm and, indeed, the image was a complete mess for negative coordinates. Thanks for noticing this!