/////////////////////////////////////////////////////////////////////////////
// dented.osl - displacement shader for dents
//
// help:
//   Makes a surface appear worn and dented.
//   
// Parameters:
//   Km - scales the overall amplitude
//   freq - scales the overall frequency
//   sharp - controls the fractal dimension of the dents (1 looks like
//           previously crumpled paper or cloth, 3 looks like worn metal).
//   shadingspace - the space that the dents (and their amplitudes) are
//                  are defined in (default: "shader")
//   Pref - if supplied, a reference mesh (defaults to the real geometry)
//
/////////////////////////////////////////////////////////////////////////////
// Copyright 2004 NVIDIA Corporation.  All Rights Reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// 
// * Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA nor the names of its contributors
//   may be used to endorse or promote products derived from this software
//   without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// (This is the Modified BSD License)
/////////////////////////////////////////////////////////////////////////////


#include "noises.h"


displacement
dented 
    [[ string help = "Dent displacement, procedural" ]]
(
    float Km = 1
        [[  string help = "Amplitude" ]],
    float sharp = 3
        [[  string help = "Sharpness",
            float min = 0 ]],
    float octaves = 6
        [[  string help = "Octaves of noise",
            float min = 1, float max = 8 ]],
    float freq = 1
        [[  string help = "Frequency" ]],
    point Pref = P
        [[  string help = "Reference pose (defaults to P)" ]],
    string shadingspace = "shader"
        [[  string help = "Shading space" ]],
    float shadingfreq = 1
        [[  string help = "Shading frequency" ]]
  )
{
    point Pshad = freq * shadingfreq * transform (shadingspace, Pref);
    float dPshad = sqrt(area(Pshad));

    float amp = turbulence (Pshad, dPshad, octaves, 2, 0.5);
    amp = pow (amp, sharp);
    displace (shadingspace, -Km*amp);
}
