/*

 * Copyright (C) 2005 Oliver Hunt <ojh16@student.canterbury.ac.nz>.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. 

 */

kernel vec4 basic(sampler inputNormalVectors, sampler inputLightVectors, __color inputLightingColor, float inputSurfaceScale, float inputSpecularConstant,

        float inputSpecularExponent, float inputKernelUnitLengthX, float inputKernelUnitLengthY)

{

    vec2 pos = samplerCoord(inputLightVectors);

    vec2 posn = samplerCoord(inputNormalVectors);

    vec3 l = sample(inputLightVectors, pos).xyz;

    vec3 n = sample(inputNormalVectors, posn).xyz;

    vec3 h = l+vec3(0.0, 0.0, 1.0);

    h = normalize(h);

    float nh = inputSpecularConstant*pow((dot(n, h)), inputSpecularExponent);

    vec4 res = inputLightingColor * nh;

    res.a = max(res.r, res.g);

    res.a = max(res.a, res.b);

    return res;

}