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/*************************************************************************
* Copyright (C) 2010 Tavian Barnes <tavianator@tavianator.com> *
* *
* This file is part of The Dimension Library. *
* *
* The Dimension Library is free software; you can redistribute it and/ *
* or modify it under the terms of the GNU Lesser General Public License *
* as published by the Free Software Foundation; either version 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension Library is distributed in the hope that it will be *
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty *
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this program. If not, see *
* <http://www.gnu.org/licenses/>. *
*************************************************************************/
/**
* @file
* Reflective finish.
*/
#include "dimension.h"
#include <math.h>
#include <stdlib.h>
/** Reflective finish payload. */
typedef struct dmnsn_reflection_params {
dmnsn_color min, max;
double falloff;
} dmnsn_reflection_params;
/** Reflective finish callback. */
static dmnsn_color
dmnsn_basic_reflection_fn(const dmnsn_reflection *reflection,
dmnsn_color reflect, dmnsn_color color,
dmnsn_vector ray, dmnsn_vector normal)
{
dmnsn_reflection_params *params = reflection->ptr;
double coeff = pow(fabs(dmnsn_vector_dot(ray, normal)), params->falloff);
return dmnsn_color_illuminate(
dmnsn_color_gradient(params->min, params->max, coeff),
reflect
);
}
dmnsn_reflection *
dmnsn_new_basic_reflection(dmnsn_color min, dmnsn_color max, double falloff)
{
dmnsn_reflection *reflection = dmnsn_new_reflection();
dmnsn_reflection_params *params
= dmnsn_malloc(sizeof(dmnsn_reflection_params));
params->min = min;
params->max = max;
params->falloff = falloff;
reflection->reflection_fn = dmnsn_basic_reflection_fn;
reflection->free_fn = dmnsn_free;
reflection->ptr = params;
return reflection;
}
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