所以我试着在c++中实现perlin噪声，并用raylib渲染它。我成功地实现了它，但不能渲染它。它只是显示黑屏，即使perlinNoise函数返回一些值。有人能帮忙吗？

#include <math.h>
#include <iostream>
#include <vector>

#include "raylib.h"

using namespace std;

int p[] = {151, 160, 137, 91,  90,  15,  131, 13,  201, 95,  96,  53,  194, 233,
           7,   225, 140, 36,  103, 30,  69,  142, 8,   99,  37,  240, 21,  10,
           23,  190, 6,   148, 247, 120, 234, 75,  0,   26,  197, 62,  94,  252,
           219, 203, 117, 35,  11,  32,  57,  177, 33,  88,  237, 149, 56,  87,
           174, 20,  125, 136, 171, 168, 68,  175, 74,  165, 71,  134, 139, 48,
           27,  166, 77,  146, 158, 231, 83,  111, 229, 122, 60,  211, 133, 230,
           220, 105, 92,  41,  55,  46,  245, 40,  244, 102, 143, 54,  65,  25,
           63,  161, 1,   216, 80,  73,  209, 76,  132, 187, 208, 89,  18,  169,
           200, 196, 135, 130, 116, 188, 159, 86,  164, 100, 109, 198, 173, 186,
           3,   64,  52,  217, 226, 250, 124, 123, 5,   202, 38,  147, 118, 126,
           255, 82,  85,  212, 207, 206, 59,  227, 47,  16,  58,  17,  182, 189,
           28,  42,  223, 183, 170, 213, 119, 248, 152, 2,   44,  154, 163, 70,
           221, 153, 101, 155, 167, 43,  172, 9,   129, 22,  39,  253, 19,  98,
           108, 110, 79,  113, 224, 232, 178, 185, 112, 104, 218, 246, 97,  228,
           251, 34,  242, 193, 238, 210, 144, 12,  191, 179, 162, 241, 81,  51,
           145, 235, 249, 14,  239, 107, 49,  192, 214, 31,  181, 199, 106, 157,
           184, 84,  204, 176, 115, 121, 50,  45,  127, 4,   150, 254, 138, 236,
           205, 93,  222, 114, 67,  29,  24,  72,  243, 141, 128, 195, 78,  66,
           215, 61,  156, 180};

float fade(float t) { return t * t * t * (6 * t * t - 15 * t + 10); }

float lerp(float a0, float a1, float t) { return a0 + t * (a1 - a0); }

float dotp(Vector2 a, Vector2 b) { return a.x * b.x + a.y * b.y; }

Vector2 grad(int a) {
  int l = a % 4;
  Vector2 v;

  if (l == 0) {
    v = {1.0, 1.0};
  } else if (l == 1) {
    v = {-1.0, 1.0};
  } else if (l == 2) {
    v = {-1.0, -1.0};
  } else {
    v = {1.0, -1.0};
  }

  return v;
}

float perlinNoise(float x, float y) {
  // 1 - Topleft, 2 - topright, 3 - bottom left, 4 - bottom right
  int xInd = (int)floor(x) & 255;
  int yInd = (int)floor(y) & 255;

  x -= (int)floor(x);
  y -= (int)floor(y);

  // Direction Vectors
  Vector2 D_1 = {x, y};
  Vector2 D_2 = {x - 1.0, y};
  Vector2 D_3 = {x, y - 1.0};
  Vector2 D_4 = {x - 1.0, y - 1.0};

  // Gradient Vectors
  Vector2 G_1 = grad(p[p[xInd + 1] + yInd + 1]);
  Vector2 G_2 = grad(p[p[xInd] + yInd + 1]);
  Vector2 G_3 = grad(p[p[xInd + 1] + yInd]);
  Vector2 G_4 = grad(p[p[xInd] + yInd]);

  // Dot Products
  float dot1 = dotp(D_1, G_1);
  float dot2 = dotp(D_2, G_2);
  float dot3 = dotp(D_3, G_3);
  float dot4 = dotp(D_4, G_4);

  // Fade Values
  float u = fade(x);
  float v = fade(y);

  return lerp(lerp(dot1, dot2, u), lerp(dot3, dot4, u), v);
}

int main(void) {
  const int screenWidth = 512;
  const int screenHeight = 512;

  cout << perlinNoise(1.5, 1.5) << '\n';

  InitWindow(screenWidth, screenHeight, "perlins go brrrrrrrrrrrrr");

  SetTargetFPS(60);

  while (!WindowShouldClose()) {
    BeginDrawing();

    ClearBackground(BLACK);

    for (int y = 0; y < 512; y++) {
      for (int x = 0; x < 512; x++) {
        float n = perlinNoise(x * 0.01, y * 0.01);
        n += 1;
        n /= 2;
        int c = round(n * 255);
        Color col{c, c, c, (char)256};
        DrawPixel(x, y, col);
      }
    }

    EndDrawing();
  }

  CloseWindow();

  return 0;
}

我试图通过给每个像素分配一些颜色来渲染它。我想问题可能是变量“颜色”。也许我没有正确地分配值。