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-rw-r--r--src/renderer/tr_noise.c92
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diff --git a/src/renderer/tr_noise.c b/src/renderer/tr_noise.c
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+/*
+===========================================================================
+Copyright (C) 1999-2005 Id Software, Inc.
+Copyright (C) 2000-2009 Darklegion Development
+
+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];
+
+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;
+
+ 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;
+}