OpenSceneGraph/examples/osgshaders/Noise.h

31 lines
1.1 KiB
C

/************************************************************************
* *
* Copyright (C) 2002 3Dlabs Inc. Ltd. *
* *
***********************************************************************/
#ifndef __ogl2_demo_h__
#define __ogl2_demo_h__
extern void SetNoiseFrequency(int frequency);
extern double noise1(double arg);
extern double noise2(double vec[2]);
extern double noise3(double vec[3]);
extern void normalize2(double vec[2]);
extern void normalize3(double vec[3]);
/*
In what follows "alpha" is the weight when the sum is formed.
Typically it is 2, As this approaches 1 the function is noisier.
"beta" is the harmonic scaling/spacing, typically 2.
*/
extern double PerlinNoise1D(double x,double alpha, double beta, int n);
extern double PerlinNoise2D(double x,double y,double alpha, double beta, int n);
extern double PerlinNoise3D(double x,double y,double z,double alpha, double beta, int n);
#endif // __ogl2_demo_h__