OpenSceneGraph/examples/osgshaders/Noise.h

52 lines
2.1 KiB
C++

/* -*-c++-*-
*
* OpenSceneGraph example, osgshaders.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/************************************************************************
* *
* 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__