src/noise.cpp


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/*
 * Minetest
 * Copyright (C) 2010-2014 celeron55, Perttu Ahola <celeron55@gmail.com>
 * Copyright (C) 2010-2014 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
 * 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 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 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.
 */

#include <math.h>
#include "noise.h"
#include <iostream>
#include <string.h> // memset
#include "debug.h"
#include "util/numeric.h"
#include "util/string.h"
#include "exceptions.h"

#define NOISE_MAGIC_X    1619
#define NOISE_MAGIC_Y    31337
#define NOISE_MAGIC_Z    52591
#define NOISE_MAGIC_SEED 1013

typedef float (*Interp2dFxn)(
		float v00, float v10, float v01, float v11,
		float x, float y);

typedef float (*Interp3dFxn)(
		float v000, float v100, float v010, float v110,
		float v001, float v101, float v011, float v111,
		float x, float y, float z);

float cos_lookup[16] = {