mirror of
https://github.com/openmoh/openmohaa.git
synced 2025-05-06 19:01:04 +03:00
96 lines
2.8 KiB
C
96 lines
2.8 KiB
C
/*
|
|
===========================================================================
|
|
Copyright (C) 1999-2005 Id Software, Inc.
|
|
Copyright (C) 2006 Robert Beckebans <trebor_7@users.sourceforge.net>
|
|
|
|
This file is part of XreaL source code.
|
|
|
|
XreaL source code is free software; you can redistribute it
|
|
and/or modify it under the terms of the GNU General Public License as
|
|
published by the Free Software Foundation; either version 2 of the License,
|
|
or (at your option) any later version.
|
|
|
|
XreaL source code 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with XreaL source code; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
===========================================================================
|
|
*/
|
|
// tr_noise.c
|
|
#include "tr_local.h"
|
|
|
|
#define NOISE_SIZE 256
|
|
#define NOISE_MASK ( NOISE_SIZE - 1 )
|
|
|
|
#define VAL( a ) s_noise_perm[ ( a ) & ( NOISE_MASK )]
|
|
#define INDEX( x, y, z, t ) VAL( x + VAL( y + VAL( z + VAL( t ) ) ) )
|
|
|
|
static float s_noise_table[NOISE_SIZE];
|
|
static int s_noise_perm[NOISE_SIZE];
|
|
|
|
#define LERP( a, b, w ) ( a * ( 1.0f - w ) + b * w )
|
|
|
|
static float GetNoiseValue(int x, int y, int z, int t)
|
|
{
|
|
int index = INDEX((int)x, (int)y, (int)z, (int)t);
|
|
|
|
return s_noise_table[index];
|
|
}
|
|
|
|
void R_NoiseInit(void)
|
|
{
|
|
int i;
|
|
|
|
srand(1001);
|
|
|
|
for(i = 0; i < NOISE_SIZE; i++)
|
|
{
|
|
s_noise_table[i] = (float)(((rand() / (float)RAND_MAX) * 2.0 - 1.0));
|
|
s_noise_perm[i] = (unsigned char)(rand() / (float)RAND_MAX * 255);
|
|
}
|
|
}
|
|
|
|
float R_NoiseGet4f(float x, float y, float z, float t)
|
|
{
|
|
int i;
|
|
int ix, iy, iz, it;
|
|
float fx, fy, fz, ft;
|
|
float front[4];
|
|
float back[4];
|
|
float fvalue, bvalue, value[2], finalvalue;
|
|
|
|
ix = (int)floor(x);
|
|
fx = x - ix;
|
|
iy = (int)floor(y);
|
|
fy = y - iy;
|
|
iz = (int)floor(z);
|
|
fz = z - iz;
|
|
it = (int)floor(t);
|
|
ft = t - it;
|
|
|
|
for(i = 0; i < 2; i++)
|
|
{
|
|
front[0] = GetNoiseValue(ix, iy, iz, it + i);
|
|
front[1] = GetNoiseValue(ix + 1, iy, iz, it + i);
|
|
front[2] = GetNoiseValue(ix, iy + 1, iz, it + i);
|
|
front[3] = GetNoiseValue(ix + 1, iy + 1, iz, it + i);
|
|
|
|
back[0] = GetNoiseValue(ix, iy, iz + 1, it + i);
|
|
back[1] = GetNoiseValue(ix + 1, iy, iz + 1, it + i);
|
|
back[2] = GetNoiseValue(ix, iy + 1, iz + 1, it + i);
|
|
back[3] = GetNoiseValue(ix + 1, iy + 1, iz + 1, it + i);
|
|
|
|
fvalue = LERP(LERP(front[0], front[1], fx), LERP(front[2], front[3], fx), fy);
|
|
bvalue = LERP(LERP(back[0], back[1], fx), LERP(back[2], back[3], fx), fy);
|
|
|
|
value[i] = LERP(fvalue, bvalue, fz);
|
|
}
|
|
|
|
finalvalue = LERP(value[0], value[1], ft);
|
|
|
|
return finalvalue;
|
|
}
|