A portable, open-source, coherent noise-generating library for C++

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# interp.h

    00001 // interp.h
    00002 //
    00003 // Copyright (C) 2003, 2004 Jason Bevins
    00004 //
    00005 // This library is free software; you can redistribute it and/or modify it
    00006 // under the terms of the GNU Lesser General Public License as published by
    00007 // the Free Software Foundation; either version 2.1 of the License, or (at
    00008 // your option) any later version.
    00009 //
    00010 // This library is distributed in the hope that it will be useful, but WITHOUT
    00011 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    00012 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
    00013 // License (COPYING.txt) for more details.
    00014 //
    00015 // You should have received a copy of the GNU Lesser General Public License
    00016 // along with this library; if not, write to the Free Software Foundation,
    00017 // Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    00018 //
    00019 // The developer's email is jlbezigvins@gmzigail.com (for great email, take
    00020 // off every 'zig'.)
    00021 //
    00022
    00023 #ifndef NOISE_INTERP_H
    00024 #define NOISE_INTERP_H
    00025
    00026 namespace noise
    00027 {
    00028
    00031
    00046   inline double CubicInterp (double n0, double n1, double n2, double n3,
    00047     double a)
    00048   {
    00049     double p = (n3 - n2) - (n0 - n1);
    00050     double q = (n0 - n1) - p;
    00051     double r = n2 - n0;
    00052     double s = n1;
    00053     return p * a * a * a + q * a * a + r * a + s;
    00054   }
    00055
    00067   inline double LinearInterp (double n0, double n1, double a)
    00068   {
    00069     return ((1.0 - a) * n0) + (a * n1);
    00070   }
    00071
    00082   inline double SCurve3 (double a)
    00083   {
    00084     return (a * a * (3.0 - 2.0 * a));
    00085   }
    00086
    00100   inline double SCurve5 (double a)
    00101   {
    00102     double a3 = a * a * a;
    00103     double a4 = a3 * a;
    00104     double a5 = a4 * a;
    00105     return (6.0 * a5) - (15.0 * a4) + (10.0 * a3);
    00106   }
    00107
    00108   // @}
    00109
    00110 }
    00111
    00112 #endif