public static float[,] GenerateNoiseMap(int mapWidth, int mapHeight, int seed, float scale, int octaves, float persistance, float lacunarity, Vector2 offset, NormalizeMode normalizeMode) {
float[,] noiseMap = new float[mapWidth,mapHeight];
System.Random prng = new System.Random (seed);
Vector2[] octaveOffsets = new Vector2[octaves];
float maxPossibleHeight = 0;
float amplitude = 1;
float frequency = 1;
for (int i = 0; i < octaves; i++) {
float offsetX = prng.Next (-100000, 100000) + offset.x;
float offsetY = prng.Next (-100000, 100000) - offset.y;
octaveOffsets [i] = new Vector2 (offsetX, offsetY);
maxPossibleHeight += amplitude;
amplitude *= persistance;
}
if (scale <= 0) {
scale = 0.0001f;
}
float maxLocalNoiseHeight = float.MinValue;
float minLocalNoiseHeight = float.MaxValue;
float halfWidth = mapWidth / 2f;
float halfHeight = mapHeight / 2f;
for (int y = 0; y < mapHeight; y++) {
for (int x = 0; x < mapWidth; x++) {
amplitude = 1;
frequency = 1;
float noiseHeight = 0;
for (int i = 0; i < octaves; i++) {
float sampleX = (x-halfWidth + octaveOffsets[i].x) / scale * frequency;
float sampleY = (y-halfHeight + octaveOffsets[i].y) / scale * frequency;
float perlinValue = Mathf.PerlinNoise (sampleX, sampleY) * 2 - 1;
noiseHeight += perlinValue * amplitude;
amplitude *= persistance;
frequency *= lacunarity;
}
if (noiseHeight > maxLocalNoiseHeight) {
maxLocalNoiseHeight = noiseHeight;
} else if (noiseHeight < minLocalNoiseHeight) {
minLocalNoiseHeight = noiseHeight;
}
noiseMap [x, y] = noiseHeight;
}
}
for (int y = 0; y < mapHeight; y++) {
for (int x = 0; x < mapWidth; x++) {
if (normalizeMode == NormalizeMode.Local) {
noiseMap [x, y] = Mathf.InverseLerp (minLocalNoiseHeight, maxLocalNoiseHeight, noiseMap [x, y]);
} else {
float normalizedHeight = (noiseMap [x, y] + 1) / (maxPossibleHeight/0.9f);
noiseMap [x, y] = Mathf.Clamp(normalizedHeight,0, int.MaxValue);
}
}
}
return noiseMap;
}