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author | Paweł Redman <pawel.redman@gmail.com> | 2017-03-22 17:56:34 +0100 |
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committer | Paweł Redman <pawel.redman@gmail.com> | 2017-03-22 17:56:34 +0100 |
commit | 6a777afc079c2a8d3af3ecd2145fe8dd50567a39 (patch) | |
tree | 520f4489cebf8564ef6cb27064ceea45cbc005b3 /src/renderer/tr_noise.c |
Diffstat (limited to 'src/renderer/tr_noise.c')
-rw-r--r-- | src/renderer/tr_noise.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/renderer/tr_noise.c b/src/renderer/tr_noise.c new file mode 100644 index 0000000..c8eeeed --- /dev/null +++ b/src/renderer/tr_noise.c @@ -0,0 +1,96 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +This file is part of Tremulous. + +Tremulous 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. + +Tremulous 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 Tremulous; 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; +} |