Nathan Gaudu destroyermanxyz

Please consider using http://lygia.xyz instead of copy/pasting this functions. It expand suport for voronoi, voronoise, fbm, noise, worley, noise, derivatives and much more, through simple file dependencies. Take a look to https://github.com/patriciogonzalezvivo/lygia/tree/main/generative

Generic 1,2,3 Noise

float rand(float n){return fract(sin(n) * 43758.5453123);}

float noise(float p){
	float fl = floor(p);
  float fc = fract(p);

	// fragment shader
	//
	// RGBA color to RGBA greyscale
	//
	// smooth transition based on u_colorFactor: 0.0 = original, 1.0 = greyscale
	//
	// http://www.johndcook.com/blog/2009/08/24/algorithms-convert-color-grayscale/
	// "The luminosity method is a more sophisticated version of the average method.
	// It also averages the values, but it forms a weighted average to account for human perception.
	// We’re more sensitive to green than other colors, so green is weighted most heavily. The formula

	float contrast(float mValue, float mScale, float mMidPoint) {
	return clamp( (mValue - mMidPoint) * mScale + mMidPoint, 0.0, 1.0);
	}

	float contrast(float mValue, float mScale) {
	return contrast(mValue, mScale, .5);
	}

	vec3 contrast(vec3 mValue, float mScale, float mMidPoint) {
	return vec3( contrast(mValue.r, mScale, mMidPoint), contrast(mValue.g, mScale, mMidPoint), contrast(mValue.b, mScale, mMidPoint) );