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Diffstat (limited to 'source/blender/freestyle/intern/system/RandGen.cpp')
| -rw-r--r-- | source/blender/freestyle/intern/system/RandGen.cpp | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/source/blender/freestyle/intern/system/RandGen.cpp b/source/blender/freestyle/intern/system/RandGen.cpp new file mode 100644 index 00000000000..193df1b4239 --- /dev/null +++ b/source/blender/freestyle/intern/system/RandGen.cpp @@ -0,0 +1,132 @@ +/* + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program 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. + * + * This program 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 this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * The Original Code is Copyright (C) 2010 Blender Foundation. + * All rights reserved. + * + * The Original Code is: all of this file. + * + * Contributor(s): none yet. + * + * ***** END GPL LICENSE BLOCK ***** + */ + +/** \file blender/freestyle/intern/system/RandGen.cpp + * \ingroup freestyle + * \brief Pseudo-random number generator + * \author Fredo Durand + * \date 20/05/2003 + */ + +#include "RandGen.h" + +// +// Macro definitions +// +/////////////////////////////////////////////////////////////////////////////// + +#define N 16 +#define MASK ((unsigned)(1 << (N - 1)) + (1 << (N - 1)) - 1) +#define X0 0x330E +#define X1 0xABCD +#define X2 0x1234 +#define A0 0xE66D +#define A1 0xDEEC +#define A2 0x5 +#define C 0xB +#define HI_BIT (1L << (2 * N - 1)) + +#define LOW(x) ((unsigned)(x) & MASK) +#define HIGH(x) LOW((x) >> N) + +#define MUL(x, y, z) \ + { \ + long l = (long)(x) * (long)(y); \ + (z)[0] = LOW(l); \ + (z)[1] = HIGH(l); \ + } + +#define CARRY(x, y) ((unsigned long)((long)(x) + (long)(y)) > MASK) +#define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y))) +#define SET3(x, x0, x1, x2) ((x)[0] = (x0), (x)[1] = (x1), (x)[2] = (x2)) +#define SETLOW(x, y, n) SET3(x, LOW((y)[n]), LOW((y)[(n)+1]), LOW((y)[(n)+2])) +#define SEED(x0, x1, x2) (SET3(x, x0, x1, x2), SET3(a, A0, A1, A2), c = C) + +#define REST(v) \ + for (i = 0; i < 3; i++) { \ + xsubi[i] = x[i]; \ + x[i] = temp[i]; \ + } \ + return (v); \ + (void) 0 + +#define NEST(TYPE, f, F) \ + TYPE f(register unsigned short *xsubi) { \ + register int i; \ + register TYPE v; \ + unsigned temp[3]; \ + for (i = 0; i < 3; i++) { \ + temp[i] = x[i]; \ + x[i] = LOW(xsubi[i]); \ + } \ + v = F(); \ + REST(v); \ + } + +static unsigned x[3] = { + X0, + X1, + X2 +}; +static unsigned a[3] = { + A0, + A1, + A2 +}; +static unsigned c = C; + +// +// Methods implementation +// +/////////////////////////////////////////////////////////////////////////////// + +real RandGen::drand48() +{ + static real two16m = 1.0 / (1L << N); + next(); + return (two16m * (two16m * (two16m * x[0] + x[1]) + x[2])); +} + +void RandGen::srand48(long seedval) +{ + SEED(X0, LOW(seedval), HIGH(seedval)); +} + +void RandGen::next() +{ + unsigned p[2], q[2], r[2], carry0, carry1; + + MUL(a[0], x[0], p); + ADDEQU(p[0], c, carry0); + ADDEQU(p[1], carry0, carry1); + MUL(a[0], x[1], q); + ADDEQU(p[1], q[0], carry0); + MUL(a[1], x[0], r); + x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] + a[0] * x[2] + a[1] * x[1] + a[2] * x[0]); + x[1] = LOW(p[1] + r[0]); + x[0] = LOW(p[0]); +} |