perlin.cpp File Reference

Code file for 2D Perlin noise functions. More...

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "Common.h"

Functions
float	noise2 (float vec[2])
void	normalize2 (float v[2])
void	swap (int &x, int &y)
void	initPerlin2D ()
	Initialize Perlin's permutation and gradient tables.
float	PerlinNoise2D (float x, float y, float alpha, float beta, int n)
	Generate a cell of 2D Perlin noise.

Function Documentation

void initPerlin2D

(

)

Initialize gradient and permutation tables.

float noise2

(

float

vec[2]

)

Compute a single octave at 2D noise at a single point.

Parameters

vec	Point at which to evaluate noise.

Returns

Noise value between -1.0 and 1.0.

void normalize2

(

float

v[2]

)

2D vector normalize. Works by side-effect.

Parameters

v	2D vector.

float PerlinNoise2D	(	float	x,
		float	y,
		float	alpha,
		float	beta,
		int	n
	)

Compute turbulence, also known as 1/f noise.

Parameters

x	X coordinate.
y	Y coordinate.
alpha	Persistence.
beta	Lacunarity.
n	Side of square grid.

Returns

Scale factor required to bring it down to range [-1, 1].

void swap	(	int &	x,
		int &	y
	)

Swap two values.

Parameters

x	First value.
y	Second value.