Differential D1615 Diff 6869 binaries/data/mods/public/maps/random/rmgen/perlin_noise.js

Changeset View

Standalone View

binaries/data/mods/public/maps/random/rmgen/perlin_noise.js

				/*
				*Perlin noise. Returns 1D array list of heights for each point given. With default paramenters returns in the range of [-1,1]
				*@param {Array} points - Points
				*@param {Number} frequency - float value >= 1. Noise size, higher value makes noise more compact
				@param {Number} octaves - int value >= 1Sub noise levels, higher the value gives noise more definition *can be as high as desired while the original frequcny doesn't reach < 1
				*@param {Number} scale - Scale size of the perlin noise (in the three axis)
				*@param {Number} vertical_scale - Scale size of the perlin noise (in the vertical axis)
				*@param {Bool} positive - Returns only on the range of [0,1] (in the case of default paremeters)
				*@return {Array}
				*/
				function perlin_noise(points, frequency = 10, octaves = 1, scale = 1, vertical_scale = 1, positive = false)
				{
				const size = points.length;
				let heights = Array(size).fill(0);
				frequency /= scale;
				let weight = 1;
				const frequency_multiplier = 1.333333;
				const weight_multiplier = 0.75;

				for (let octave = 0; octave < octaves; octave++)
				{
				let noise2D = new Noise2D(frequency);
				for (let i = 0; i < size; i++)
				{
				const ix = (points[i].x / 256.0) % 1;
				const iy = (points[i].y / 256.0) % 1;
				//noise2D gives values between [0.15,0.85]
				//transform to a range of [-1,1]
				const val = (noise2D.get(ix, iy) - 0.15) / 0.7 * 2 - 1;
				heights[i] += val * weight;
				}
				frequency *= frequency_multiplier;
				weight *= weight_multiplier;
				}
				heights.forEach((v, i, a) => a[i] = scale vertical_scale)

				if (positive)
				{
				const hdisp = vertical_scale * scale * Array(octaves).fill().map((e, i) => Math.pow(weight_multiplier, i + 1)).reduce((a, b) => a + b);
				heights.forEach((v, i, a) => a[i] = (v + hdisp) * 0.5)
				}

				return heights;
				}

				/*
				*Perlin noise for individual points
				*/
				function perlin_noise_point(frequency = 10, octaves = 1, scale = 1, vertical_scale = 1, positive = false)
				{
				this.frequency = frequency / scale;
				this.octaves = octaves;
				this.scale = scale;
				this.vertical_scale = vertical_scale;
				this.positive = positive;
				this.frequency_multiplier = 1.333333;
				this.weight_multiplier = 0.75;
				let frequency_i = this.frequency;
				let weight_i = 1;

				this.noise2D = [];
				this.weights = [];
				for (let octave = 0; octave < this.octaves; octave++)
				{
				this.noise2D.push(new Noise2D(frequency_i))
				this.weights.push(weight_i)
				frequency_i *= this.frequency_multiplier;
				weight_i *= this.weight_multiplier;
				}

				this.hdisp = this.vertical_scale * this.scale * Array(this.octaves).fill().map((e, i) => Math.pow(this.weight_multiplier, i + 1)).reduce((a, b) => a + b)
				}

				perlin_noise_point.prototype.get = function(point)
				{
				let height = 0;
				for (let i = 0; i < this.octaves; i++)
				{
				const x = (point.x / 256.0) % 1;
				const y = (point.y / 256.0) % 1;
				//noise2D gives values between [0.15,0.85]
				//give range [-1,1]
				const val = (this.noise2D[i].get(x, y) - 0.15) / 0.7 * 2 - 1;
				height += val * this.weights[i];
				}

				height = this.scale this.vertical_scale;

				return this.positive ? (height + this.hdisp) * 0.5 : height;
				}
				No newline at end of file