public PerlinNoise(int octaves, float amplitude, float roughness, Vector2 offset, NormaliseMode normaliseMode)
{
this.seed = new System.Random().Next(1000000000);
this.octaves = octaves;
this.amplitude = amplitude;
this.roughness = roughness;
this.offset = offset;
this.normaliseMode = normaliseMode;
System.Random prng = new System.Random(this.seed);
this.octaveOffsets = new Vector2[this.octaves];
for (int i = 0; i < octaves; i++)
{
float offsetX = prng.Next(-100000, 100000) + this.offset.x;
float offsetY = prng.Next(-100000, 100000) - this.offset.y;
this.octaveOffsets[i] = new Vector2(offsetX, offsetY);
maxPossibleHeight += (float)Mathf.Pow(this.roughness, i) * this.amplitude;
}
}
public static float[,] GenerateNoiseMap(int width, int height, float scale, int octaves, float persistance, float lacunarity, int seed, Vector2 offset, NormaliseMode normMode)
{
if (scale <= 0)
{
scale = 0.001f;
}
System.Random prng = new System.Random(seed);
float amplitude = 1;
float freq = 1;
float noiseHeight = 0;
float maxPossHeight = 0f;
float minPossHeight = 0f;
// Sample each octave from a new part (increases noise)
Vector2[] octaveOffsets = new Vector2[octaves];
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);
maxPossHeight += amplitude;
amplitude *= persistance;
}
// Used to normalise the noisemap at end
float maxNoiseVal = float.MinValue;
float minNoiseVal = float.MaxValue;
// Used to offset the noise to the centre instead of top-left
float hWidth = width / 2f;
float hHeight = height / 2f;
float[,] noiseMap = new float[width, height];
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
amplitude = 1;
freq = 1;
noiseHeight = 0;
for (int i = 0; i < octaves; i++)
{
float sampleX = (x - hWidth + octaveOffsets[i].x) / scale * freq;
float sampleY = (y - hHeight + octaveOffsets[i].y) / scale * freq;
float perlinVal = Mathf.PerlinNoise(sampleX, sampleY) * 2 - 1;
noiseHeight += perlinVal * amplitude;
amplitude *= persistance;
freq *= lacunarity;
}
if (noiseHeight > maxNoiseVal)
{
maxNoiseVal = noiseHeight;
}
else if (noiseHeight < minNoiseVal)
{
minNoiseVal = noiseHeight;
}
noiseMap[x, height - 1 - y] = noiseHeight;
}
}
// Normalise noisemap between min and max values to be between 0f - 1f
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
if (normMode == NormaliseMode.Local)
{
noiseMap[x, y] = Mathf.InverseLerp(minNoiseVal, maxNoiseVal, noiseMap[x, y]);
}
if (normMode == NormaliseMode.Global)
{
noiseMap[x, y] = ((noiseMap[x, y] + 1) / (2f * maxPossHeight / 1.75f));
}
}
}
return(noiseMap);
}
public static float[,] GenerateNoiseMap(int mapWidth, int mapHeight, int seed, float scale, int octaves, float persistance, float lacunarity, Vector2 offset, NormaliseMode normalisedMode)
{
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 (normalisedMode == NormaliseMode.Local)
{
noiseMap[x, y] = Mathf.InverseLerp(minLocalNoiseHeight, maxLocalNoiseHeight, noiseMap[x, y]);
}
else
{
float normalisedHeight = (noiseMap[x, y] + 1) / (maxPossibleHeight);
noiseMap[x, y] = Mathf.Clamp(normalisedHeight, 0, int.MaxValue);
}
}
}
return(noiseMap);
}
public static float[,] GenerateNoiseMap(int mapWidth, int mapHeight, float scale, int octaves, float persistance, float lacunarity, int seed, Vector2 offset, NormaliseMode normaliseMode)
{
System.Random prng = new System.Random(seed);
Vector2[] octavesOffsets = new Vector2[octaves];
float maxPossibleHeight = 0;
float amplitude = 1;
float frequency = 1;
for (int i = 0; i < octaves; i++) //randomly offset octabes from each other to make random landscape
{
float offsetx = prng.Next(-100000, 100000) + offset.x; //empirical values
float offsety = prng.Next(-100000, 100000) - offset.y;
octavesOffsets [i] = new Vector2(offsetx, offsety);
maxPossibleHeight += amplitude;
amplitude *= persistance;
}
float[,] noiseMap = new float [mapWidth, mapHeight];
if (scale <= 0)
{
scale = 0.0001f;
}
float maxLocalNoiseHeight = float.MinValue;
float minLocalNoiseHeight = float.MaxValue;
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 + octavesOffsets [i].x) / scale * frequency; // + offset.x;
float sampleY = (y + octavesOffsets[i].y) / scale * frequency; //+ offset.y;
float perlinValue = Mathf.PerlinNoise(sampleX, sampleY) * 2 - 1; // multiply by 2 and negate one to ensure in range -1 to 1
noiseHeight += perlinValue * amplitude;
amplitude *= persistance;
frequency *= lacunarity;
}
//get range of noise height values to defina a max and a min value (to allow for normalisation)
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 (normaliseMode == NormaliseMode.local) //if generating single chunk - ie not procedural
{
noiseMap [x, y] = Mathf.InverseLerp(minLocalNoiseHeight, maxLocalNoiseHeight, noiseMap [x, y]); //inverselerp method standardises the noiseheingt (it returns a value between 0-1)
}
else
{
float normalisedHeight = (noiseMap [x, y] + 1) / (2f * maxPossibleHeight / 5f); //reverses the operation above. The final float is an empirical correction to compensate for scaling by the maxpossible height
noiseMap[x, y] = Mathf.Clamp(normalisedHeight, 0, int.MaxValue);
}
}
}
return(noiseMap);
}
public static float[,] GenerateNoiseMap(int _width, int _height, int _seed, float _scale, int _octaves, float _persistence, float _lacunarity, Vector2 _offset, NormaliseMode _normaliseMode)
{
float[,] noiseMap = new float[_width, _height];
System.Random prng = new System.Random(_seed);
Vector2[] octaveOffsets = new Vector2[_octaves];
float maxGlobalNoiseHeight = 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);
maxGlobalNoiseHeight += amplitude;
amplitude *= _persistence;
}
if (_scale <= 0)
{
_scale = 0.0001f;
}
float maxLocalNoiseHeight = float.MinValue;
float minLocalNoiseHeight = float.MaxValue;
float halfWidth = _width / 2;
float halfHeight = _height / 2;
for (int y = 0; y < _height; y++)
{
for (int x = 0; x < _width; x++)
{
frequency = 1;
amplitude = 1;
float noiseHeight = 0;
for (int i = 0; i < _octaves; i++)
{
// the higher the freuency, the further away the sample points,
// this means the height changes more rapidly
float sampleX = (x - halfWidth + octaveOffsets[i].x) / _scale * frequency;
float sampleY = (y - halfHeight + octaveOffsets[i].y) / _scale * frequency;
// generate values between -1 and 1 so that there can be dips in the
// terrain when it is later generated
float perlinValue = Mathf.PerlinNoise(sampleX, sampleY) * 2 - 1;
noiseHeight += perlinValue * amplitude;
amplitude *= _persistence;
// frequency increases per octave since lacunarity is greater
// than 1.
frequency *= _lacunarity;
}
// work out the range of the noisemap values
if (noiseHeight > maxLocalNoiseHeight)
{
maxLocalNoiseHeight = noiseHeight;
}
else if (noiseHeight < minLocalNoiseHeight)
{
minLocalNoiseHeight = noiseHeight;
}
noiseMap[x, y] = noiseHeight;
}
}
// normalise the noise map
for (int y = 0; y < _height; y++)
{
for (int x = 0; x < _width; x++)
{
if (_normaliseMode == NormaliseMode.Local)
{
noiseMap[x, y] = Mathf.InverseLerp(minLocalNoiseHeight, maxLocalNoiseHeight, noiseMap[x, y]);
}
else
{
// make the height values consistent across the entire map
float normalizedHeight = (noiseMap[x, y] + 1) / (2 * maxGlobalNoiseHeight / 1.75f);
noiseMap[x, y] = Mathf.Clamp(normalizedHeight, 0, int.MaxValue);
}
}
}
return(noiseMap);
}
