Open Shading Language

/*
Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
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 Sony Pictures Imageworks 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.
*/


// A veritable cornucopia of noise-based functions.


shader noise
    (
        string type = "perlin",
        int dimensions = 3,
        float frequency = 1,
        float lacunarity = 2,
        float gain = 0.5,
        int octaves = 4,
        float amplitude = 1,
        int signed = 0,
        point p = P,
        output float F = 0,
        output color C = 0
    )
{
    // We need to declare these temporary variables because you can't
    // take the address of an output param in a function call.
    float ftmp;
    color ctmp;

    // Call the right noise function based on the 'type' string
    if (type == "perlin" || type == "noise") {
        if (dimensions == 2)
            ftmp = noise ("perlin", point(p[0]*frequency, p[1]*frequency, 0));
        else if (dimensions == 4)
            ftmp = noise ("perlin", p, frequency);  // 4-D version
        else
            ftmp = noise ("perlin", p * frequency);
    } else if (type == "uperlin" || type == "unoise") {
        if (dimensions == 2)
            ftmp = noise ("uperlin", point(p[0]*frequency, p[1]*frequency, 0));
        else if (dimensions == 4)
            ftmp = noise ("uperlin", p, frequency);  // 4-D version
        else
            ftmp = noise ("uperlin", p * frequency);
    } else if (type == "cell" || type == "cellnoise") {
        if (dimensions == 2)
            ftmp = cellnoise (point(p[0]*frequency, p[1]*frequency, 0));
        else if (dimensions == 4)
            ftmp = cellnoise (p, frequency);
        else
            ftmp = cellnoise (p * frequency);
    } else if (type == "hash" || type == "hashnoise") {
        if (dimensions == 2)
            ftmp = hashnoise (point(p[0]*frequency, p[1]*frequency, 0));
        else if (dimensions == 4)
            ftmp = hashnoise (p, frequency);
        else
            ftmp = hashnoise (p * frequency);
    } else if (type == "worley") {
        if (dimensions == 2)
            ftmp = worleynoise (point(p[0]*frequency, p[1]*frequency, 0), lacunarity, ftmp, ctmp);
        else if (dimensions == 4)
            ftmp = worleynoise (p, frequency, lacunarity, ftmp, ctmp);
        else
            ftmp = worleynoise (p * frequency, lacunarity, ftmp, ctmp);
    } else if (type == "fbm") {
        if (dimensions == 2)
            ftmp = fbm (point(p[0]*frequency, p[1]*frequency, 0), octaves, lacunarity, gain);
        else
            ftmp = fbm (p*frequency, octaves, lacunarity, gain);
    } else if (type == "turbulence" || type == "turb") {
        if (dimensions == 2)
            ftmp = turbulence (point(p[0]*frequency, p[1]*frequency, 0), octaves, lacunarity, gain);
        else
            ftmp = turbulence (p*frequency, octaves, lacunarity, gain);
    } else if (type == "vnoise") {
        if (dimensions == 2)
            ctmp = vnoise (point(p[0]*frequency, p[1]*frequency, 0));
        else if (dimensions == 4)
            ctmp = vnoise (p, frequency);
        else
            ctmp = vnoise (p * frequency);
    } else if (type == "vfbm") {
        if (dimensions == 2)
            ctmp = vfbm (point(p[0]*frequency, p[1]*frequency, 0), octaves, lacunarity, gain);
        else
            ctmp = vfbm (p*frequency, octaves, lacunarity, gain);
    } else if (type == "vturbulence" || type == "vturb") {
        if (dimensions == 2)
            ctmp = vturbulence (point(p[0]*frequency, p[1]*frequency, 0), octaves, lacunarity, gain);
        else
            ctmp = vturbulence (p*frequency, octaves, lacunarity, gain);
    } else {
        // Unknown noise type -- just output 0
        ftmp = 0;
        ctmp = 0;
    }


    if (isconnected(C)) {
        // If C is hooked up, assume they want the color version
        if (signed)
            C = ctmp * amplitude;
        else
            C = (ctmp * 0.5 + 0.5) * amplitude;
        F = luminance(C);
    } else {
        // If C is not hooked up, assume they want the float version
        if (signed)
            F = ftmp * amplitude;
        else
            F = (ftmp * 0.5 + 0.5) * amplitude;
        C = F;
    }
}